Add m-esr52 at 52.6.0

30 files changed, 4815 insertions, 0 deletions

diff --git a/embedding/components/windowwatcher/moz.build b/embedding/components/windowwatcher/moz.build
new file mode 100644
index 000000000..31aa718c9
--- /dev/null
+++ b/embedding/components/windowwatcher/moz.build
@@ -0,0 +1,49 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+TEST_DIRS += ['test']
+
+XPIDL_SOURCES += [
+    'nsIDialogParamBlock.idl',
+    'nsIPromptFactory.idl',
+    'nsIPromptService.idl',
+    'nsIPromptService2.idl',
+    'nsIWindowWatcher.idl',
+    'nsPIPromptService.idl',
+    'nsPIWindowWatcher.idl',
+]
+
+XPIDL_MODULE = 'windowwatcher'
+
+EXPORTS += [
+    'nsPromptUtils.h',
+]
+
+UNIFIED_SOURCES += [
+    'nsAutoWindowStateHelper.cpp',
+    'nsWindowWatcher.cpp',
+]
+
+EXPORTS += [
+    'nsWindowWatcher.h',
+]
+
+if CONFIG['MOZ_XUL']:
+    UNIFIED_SOURCES += [
+        'nsDialogParamBlock.cpp',
+    ]
+
+FINAL_LIBRARY = 'xul'
+# For nsJSUtils
+LOCAL_INCLUDES += [
+    '/docshell/base',
+    '/dom/base',
+]
+
+if CONFIG['GNU_CXX']:
+    CXXFLAGS += ['-Wno-error=shadow']
+
+include('/ipc/chromium/chromium-config.mozbuild')
diff --git a/embedding/components/windowwatcher/nsAutoWindowStateHelper.cpp b/embedding/components/windowwatcher/nsAutoWindowStateHelper.cpp
new file mode 100644
index 000000000..068f2a6dc
--- /dev/null
+++ b/embedding/components/windowwatcher/nsAutoWindowStateHelper.cpp
@@ -0,0 +1,73 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsAutoWindowStateHelper.h"
+
+#include "mozilla/dom/Event.h"
+#include "nsIDocument.h"
+#include "nsIDOMEvent.h"
+#include "nsIDOMWindow.h"
+#include "nsPIDOMWindow.h"
+#include "nsString.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+/****************************************************************
+ ****************** nsAutoWindowStateHelper *********************
+ ****************************************************************/
+
+nsAutoWindowStateHelper::nsAutoWindowStateHelper(nsPIDOMWindowOuter* aWindow)
+  : mWindow(aWindow)
+  , mDefaultEnabled(DispatchEventToChrome("DOMWillOpenModalDialog"))
+{
+  if (mWindow) {
+    mWindow->EnterModalState();
+  }
+}
+
+nsAutoWindowStateHelper::~nsAutoWindowStateHelper()
+{
+  if (mWindow) {
+    mWindow->LeaveModalState();
+  }
+
+  if (mDefaultEnabled) {
+    DispatchEventToChrome("DOMModalDialogClosed");
+  }
+}
+
+bool
+nsAutoWindowStateHelper::DispatchEventToChrome(const char* aEventName)
+{
+  // XXXbz should we skip dispatching the event if the inner changed?
+  // That is, should we store both the inner and the outer?
+  if (!mWindow) {
+    return true;
+  }
+
+  // The functions of nsContentUtils do not provide the required behavior,
+  // so the following is inlined.
+  nsIDocument* doc = mWindow->GetExtantDoc();
+  if (!doc) {
+    return true;
+  }
+
+  ErrorResult rv;
+  RefPtr<Event> event = doc->CreateEvent(NS_LITERAL_STRING("Events"), rv);
+  if (rv.Failed()) {
+    rv.SuppressException();
+    return false;
+  }
+  event->InitEvent(NS_ConvertASCIItoUTF16(aEventName), true, true);
+  event->SetTrusted(true);
+  event->WidgetEventPtr()->mFlags.mOnlyChromeDispatch = true;
+
+  nsCOMPtr<EventTarget> target = do_QueryInterface(mWindow);
+  bool defaultActionEnabled;
+  target->DispatchEvent(event, &defaultActionEnabled);
+  return defaultActionEnabled;
+}
diff --git a/embedding/components/windowwatcher/nsAutoWindowStateHelper.h b/embedding/components/windowwatcher/nsAutoWindowStateHelper.h
new file mode 100644
index 000000000..875fb4ba0
--- /dev/null
+++ b/embedding/components/windowwatcher/nsAutoWindowStateHelper.h
@@ -0,0 +1,35 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef __nsAutoWindowStateHelper_h
+#define __nsAutoWindowStateHelper_h
+
+#include "nsCOMPtr.h"
+#include "nsPIDOMWindow.h"
+
+/**
+ * Helper class for dealing with notifications around opening modal
+ * windows.
+ */
+
+class nsPIDOMWindowOuter;
+
+class nsAutoWindowStateHelper
+{
+public:
+  explicit nsAutoWindowStateHelper(nsPIDOMWindowOuter* aWindow);
+  ~nsAutoWindowStateHelper();
+
+  bool DefaultEnabled() { return mDefaultEnabled; }
+
+protected:
+  bool DispatchEventToChrome(const char* aEventName);
+
+  nsCOMPtr<nsPIDOMWindowOuter> mWindow;
+  bool mDefaultEnabled;
+};
+
+#endif
diff --git a/embedding/components/windowwatcher/nsDialogParamBlock.cpp b/embedding/components/windowwatcher/nsDialogParamBlock.cpp
new file mode 100644
index 000000000..f6f7af967
--- /dev/null
+++ b/embedding/components/windowwatcher/nsDialogParamBlock.cpp
@@ -0,0 +1,101 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsDialogParamBlock.h"
+#include "nsString.h"
+#include "nsReadableUtils.h"
+
+NS_IMPL_ISUPPORTS(nsDialogParamBlock, nsIDialogParamBlock)
+
+nsDialogParamBlock::nsDialogParamBlock()
+  : mNumStrings(0)
+  , mString(nullptr)
+{
+  for (int32_t i = 0; i < kNumInts; i++) {
+    mInt[i] = 0;
+  }
+}
+
+nsDialogParamBlock::~nsDialogParamBlock()
+{
+  delete[] mString;
+}
+
+NS_IMETHODIMP
+nsDialogParamBlock::SetNumberStrings(int32_t aNumStrings)
+{
+  if (mString) {
+    return NS_ERROR_ALREADY_INITIALIZED;
+  }
+
+  mString = new nsString[aNumStrings];
+  if (!mString) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  mNumStrings = aNumStrings;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDialogParamBlock::GetInt(int32_t aIndex, int32_t* aResult)
+{
+  nsresult rv = InBounds(aIndex, kNumInts);
+  if (rv == NS_OK) {
+    *aResult = mInt[aIndex];
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+nsDialogParamBlock::SetInt(int32_t aIndex, int32_t aInt)
+{
+  nsresult rv = InBounds(aIndex, kNumInts);
+  if (rv == NS_OK) {
+    mInt[aIndex] = aInt;
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+nsDialogParamBlock::GetString(int32_t aIndex, char16_t** aResult)
+{
+  if (mNumStrings == 0) {
+    SetNumberStrings(kNumStrings);
+  }
+  nsresult rv = InBounds(aIndex, mNumStrings);
+  if (rv == NS_OK) {
+    *aResult = ToNewUnicode(mString[aIndex]);
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+nsDialogParamBlock::SetString(int32_t aIndex, const char16_t* aString)
+{
+  if (mNumStrings == 0) {
+    SetNumberStrings(kNumStrings);
+  }
+  nsresult rv = InBounds(aIndex, mNumStrings);
+  if (rv == NS_OK) {
+    mString[aIndex] = aString;
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+nsDialogParamBlock::GetObjects(nsIMutableArray** aObjects)
+{
+  NS_ENSURE_ARG_POINTER(aObjects);
+  NS_IF_ADDREF(*aObjects = mObjects);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDialogParamBlock::SetObjects(nsIMutableArray* aObjects)
+{
+  mObjects = aObjects;
+  return NS_OK;
+}
diff --git a/embedding/components/windowwatcher/nsDialogParamBlock.h b/embedding/components/windowwatcher/nsDialogParamBlock.h
new file mode 100644
index 000000000..c1b06ea53
--- /dev/null
+++ b/embedding/components/windowwatcher/nsDialogParamBlock.h
@@ -0,0 +1,45 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef __nsDialogParamBlock_h
+#define __nsDialogParamBlock_h
+
+#include "nsIDialogParamBlock.h"
+#include "nsIMutableArray.h"
+#include "nsCOMPtr.h"
+
+// {4E4AAE11-8901-46cc-8217-DAD7C5415873}
+#define NS_DIALOGPARAMBLOCK_CID \
+  {0x4e4aae11, 0x8901, 0x46cc, {0x82, 0x17, 0xda, 0xd7, 0xc5, 0x41, 0x58, 0x73}}
+
+class nsString;
+
+class nsDialogParamBlock : public nsIDialogParamBlock
+{
+public:
+  nsDialogParamBlock();
+
+  NS_DECL_NSIDIALOGPARAMBLOCK
+  NS_DECL_ISUPPORTS
+
+protected:
+  virtual ~nsDialogParamBlock();
+
+private:
+  enum { kNumInts = 8, kNumStrings = 16 };
+
+  nsresult InBounds(int32_t aIndex, int32_t aMax)
+  {
+    return aIndex >= 0 && aIndex < aMax ? NS_OK : NS_ERROR_ILLEGAL_VALUE;
+  }
+
+  int32_t mInt[kNumInts];
+  int32_t mNumStrings;
+  nsString* mString;
+  nsCOMPtr<nsIMutableArray> mObjects;
+};
+
+#endif
diff --git a/embedding/components/windowwatcher/nsIDialogParamBlock.idl b/embedding/components/windowwatcher/nsIDialogParamBlock.idl
new file mode 100644
index 000000000..d917776ec
--- /dev/null
+++ b/embedding/components/windowwatcher/nsIDialogParamBlock.idl
@@ -0,0 +1,42 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+ 
+#include "nsISupports.idl"
+interface nsIMutableArray;
+
+/**
+ * An interface to pass strings, integers and nsISupports to a dialog
+ */
+
+[scriptable, uuid(f76c0901-437a-11d3-b7a0-e35db351b4bc)]
+interface nsIDialogParamBlock:  nsISupports {
+
+  /** Get or set an integer to pass.
+   * Index must be in the range 0..7
+   */
+  int32_t GetInt( in int32_t inIndex );
+  void SetInt( in int32_t inIndex, in int32_t inInt );
+
+  /** Set the maximum number of strings to pass. Default is 16.
+   * Use before setting any string (If you want to change it from the default).
+   */
+  void SetNumberStrings( in int32_t inNumStrings );
+
+  /** Get or set an string to pass.
+    * Index starts at 0
+    */
+  wstring GetString( in int32_t inIndex );
+  void SetString( in int32_t inIndex, in wstring inString);
+  
+  /**
+   * A place where you can store an nsIMutableArray to pass nsISupports 
+   */
+  attribute nsIMutableArray objects;
+};
+
+%{C++
+#define NS_DIALOGPARAMBLOCK_CONTRACTID "@mozilla.org/embedcomp/dialogparam;1"
+%}
+
diff --git a/embedding/components/windowwatcher/nsIPromptFactory.idl b/embedding/components/windowwatcher/nsIPromptFactory.idl
new file mode 100644
index 000000000..b16db3d49
--- /dev/null
+++ b/embedding/components/windowwatcher/nsIPromptFactory.idl
@@ -0,0 +1,22 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface mozIDOMWindowProxy;
+
+/**
+ * This interface allows creating various prompts that have a specific parent.
+ */
+[scriptable, uuid(2803541c-c96a-4ff1-bd7c-9cb566d46aeb)]
+interface nsIPromptFactory : nsISupports
+{
+  /**
+   * Returns an object implementing the specified interface that creates
+   * prompts parented to aParent.
+   */
+  void getPrompt(in mozIDOMWindowProxy aParent, in nsIIDRef iid,
+                 [iid_is(iid),retval] out nsQIResult result);
+};
+
diff --git a/embedding/components/windowwatcher/nsIPromptService.idl b/embedding/components/windowwatcher/nsIPromptService.idl
new file mode 100644
index 000000000..24c75e3a9
--- /dev/null
+++ b/embedding/components/windowwatcher/nsIPromptService.idl
@@ -0,0 +1,346 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface mozIDOMWindowProxy;
+
+/**
+ * This is the interface to the embeddable prompt service; the service that
+ * implements nsIPrompt.  Its interface is designed to be just nsIPrompt, each
+ * method modified to take a parent window parameter.
+ *
+ * Accesskeys can be attached to buttons and checkboxes by inserting an &
+ * before the accesskey character in the checkbox message or button title.  For
+ * a real &, use && instead.  (A "button title" generally refers to the text
+ * label of a button.)
+ *
+ * One note: in all cases, the parent window parameter can be null.  However,
+ * these windows are all intended to have parents.  So when no parent is
+ * specified, the implementation should try hard to find a suitable foster
+ * parent.
+ *
+ * Implementations are free to choose how they present the various button
+ * types.  For example, while prompts that give the user a choice between OK
+ * and Cancel are required to return a boolean value indicating whether or not
+ * the user accepted the prompt (pressed OK) or rejected the prompt (pressed
+ * Cancel), the implementation of this interface could very well speak the
+ * prompt to the user instead of rendering any visual user-interface.  The
+ * standard button types are merely idioms used to convey the nature of the
+ * choice the user is to make.
+ *
+ * Because implementations of this interface may loosely interpret the various
+ * button types, it is advised that text messages passed to these prompts do
+ * not refer to the button types by name.  For example, it is inadvisable to
+ * tell the user to "Press OK to proceed."  Instead, such a prompt might be
+ * rewritten to ask the user: "Would you like to proceed?"
+ */
+[scriptable, uuid(404ebfa2-d8f4-4c94-8416-e65a55f9df5a)]
+interface nsIPromptService : nsISupports
+{
+  /**
+   * Puts up an alert dialog with an OK button.
+   *
+   * @param aParent
+   *        The parent window or null.
+   * @param aDialogTitle
+   *        Text to appear in the title of the dialog.
+   * @param aText
+   *        Text to appear in the body of the dialog.
+   */
+  void alert(in mozIDOMWindowProxy aParent,
+             in wstring aDialogTitle,
+             in wstring aText);
+
+  /**
+   * Puts up an alert dialog with an OK button and a labeled checkbox.
+   *
+   * @param aParent
+   *        The parent window or null.
+   * @param aDialogTitle
+   *        Text to appear in the title of the dialog.
+   * @param aText
+   *        Text to appear in the body of the dialog.
+   * @param aCheckMsg
+   *        Text to appear with the checkbox.
+   * @param aCheckState
+   *        Contains the initial checked state of the checkbox when this method
+   *        is called and the final checked state after this method returns.
+   */
+  void alertCheck(in mozIDOMWindowProxy aParent,
+                  in wstring aDialogTitle,
+                  in wstring aText,
+                  in wstring aCheckMsg,
+                  inout boolean aCheckState);
+
+  /**
+   * Puts up a dialog with OK and Cancel buttons.
+   *
+   * @param aParent
+   *        The parent window or null.
+   * @param aDialogTitle
+   *        Text to appear in the title of the dialog.
+   * @param aText
+   *        Text to appear in the body of the dialog.
+   *
+   * @return true for OK, false for Cancel
+   */
+  boolean confirm(in mozIDOMWindowProxy aParent,
+                  in wstring aDialogTitle,
+                  in wstring aText);
+
+  /**
+   * Puts up a dialog with OK and Cancel buttons and a labeled checkbox.
+   *
+   * @param aParent
+   *        The parent window or null.
+   * @param aDialogTitle
+   *        Text to appear in the title of the dialog.
+   * @param aText
+   *        Text to appear in the body of the dialog.
+   * @param aCheckMsg
+   *        Text to appear with the checkbox.
+   * @param aCheckState
+   *        Contains the initial checked state of the checkbox when this method
+   *        is called and the final checked state after this method returns.
+   *
+   * @return true for OK, false for Cancel
+   */
+  boolean confirmCheck(in mozIDOMWindowProxy aParent,
+                       in wstring aDialogTitle,
+                       in wstring aText,
+                       in wstring aCheckMsg,
+                       inout boolean aCheckState);
+
+  /**
+   * Button Flags
+   *
+   * The following flags are combined to form the aButtonFlags parameter passed
+   * to confirmEx.  See confirmEx for more information on how the flags may be
+   * combined.
+   */
+   
+  /**
+   * Button Position Flags
+   */
+  const unsigned long BUTTON_POS_0              = 1;
+  const unsigned long BUTTON_POS_1              = 1 << 8;
+  const unsigned long BUTTON_POS_2              = 1 << 16;
+     
+  /**
+   * Button Title Flags (used to set the labels of buttons in the prompt)
+   */
+  const unsigned long BUTTON_TITLE_OK            = 1;
+  const unsigned long BUTTON_TITLE_CANCEL        = 2;
+  const unsigned long BUTTON_TITLE_YES           = 3;
+  const unsigned long BUTTON_TITLE_NO            = 4;
+  const unsigned long BUTTON_TITLE_SAVE          = 5;
+  const unsigned long BUTTON_TITLE_DONT_SAVE     = 6;
+  const unsigned long BUTTON_TITLE_REVERT        = 7;
+  const unsigned long BUTTON_TITLE_IS_STRING     = 127;
+  
+  /**
+   * Button Default Flags (used to select which button is the default one)
+   */
+  const unsigned long BUTTON_POS_0_DEFAULT       = 0;
+  const unsigned long BUTTON_POS_1_DEFAULT       = 1 << 24;
+  const unsigned long BUTTON_POS_2_DEFAULT       = 1 << 25;
+
+  /**
+   * Causes the buttons to be initially disabled.  They are enabled after a
+   * timeout expires.  The implementation may interpret this loosely as the
+   * intent is to ensure that the user does not click through a security dialog
+   * too quickly.  Strictly speaking, the implementation could choose to ignore
+   * this flag.
+   */
+  const unsigned long BUTTON_DELAY_ENABLE        = 1 << 26;
+
+  /**
+   * Selects the standard set of OK/Cancel buttons.
+   */
+  const unsigned long STD_OK_CANCEL_BUTTONS      = (BUTTON_TITLE_OK     * BUTTON_POS_0) +
+                                                   (BUTTON_TITLE_CANCEL * BUTTON_POS_1);
+
+  /**
+   * Selects the standard set of Yes/No buttons.
+   */
+  const unsigned long STD_YES_NO_BUTTONS         = (BUTTON_TITLE_YES * BUTTON_POS_0) +
+                                                   (BUTTON_TITLE_NO  * BUTTON_POS_1);
+
+
+  /**
+   * Puts up a dialog with up to 3 buttons and an optional, labeled checkbox.
+   *
+   * @param aParent
+   *        The parent window or null.
+   * @param aDialogTitle
+   *        Text to appear in the title of the dialog.
+   * @param aText
+   *        Text to appear in the body of the dialog.
+   * @param aButtonFlags
+   *        A combination of Button Flags.
+   * @param aButton0Title
+   *        Used when button 0 uses TITLE_IS_STRING
+   * @param aButton1Title
+   *        Used when button 1 uses TITLE_IS_STRING
+   * @param aButton2Title
+   *        Used when button 2 uses TITLE_IS_STRING
+   * @param aCheckMsg
+   *        Text to appear with the checkbox.  Null if no checkbox.
+   * @param aCheckState    
+   *        Contains the initial checked state of the checkbox when this method
+   *        is called and the final checked state after this method returns.
+   *
+   * @return index of the button pressed.
+   *
+   * Buttons are numbered 0 - 2. The implementation can decide whether the
+   * sequence goes from right to left or left to right.  Button 0 is the
+   * default button unless one of the Button Default Flags is specified.
+   *
+   * A button may use a predefined title, specified by one of the Button Title
+   * Flags values.  Each title value can be multiplied by a position value to
+   * assign the title to a particular button.  If BUTTON_TITLE_IS_STRING is
+   * used for a button, the string parameter for that button will be used.  If
+   * the value for a button position is zero, the button will not be shown.
+   *
+   * In general, aButtonFlags is constructed per the following example:
+   *
+   *   aButtonFlags = (BUTTON_POS_0) * (BUTTON_TITLE_AAA) +
+   *                  (BUTTON_POS_1) * (BUTTON_TITLE_BBB) +
+   *                   BUTTON_POS_1_DEFAULT;
+   *
+   * where "AAA" and "BBB" correspond to one of the button titles.
+   */
+  int32_t confirmEx(in mozIDOMWindowProxy aParent,
+                    in wstring aDialogTitle,
+                    in wstring aText,
+                    in unsigned long aButtonFlags,
+                    in wstring aButton0Title,
+                    in wstring aButton1Title,
+                    in wstring aButton2Title,
+                    in wstring aCheckMsg,
+                    inout boolean aCheckState);
+
+  /**
+   * Puts up a dialog with an edit field and an optional, labeled checkbox.
+   *
+   * @param aParent
+   *        The parent window or null.
+   * @param aDialogTitle
+   *        Text to appear in the title of the dialog.
+   * @param aText
+   *        Text to appear in the body of the dialog.
+   * @param aValue
+   *        Contains the default value for the dialog field when this method
+   *        is called (null value is ok).  Upon return, if the user pressed
+   *        OK, then this parameter contains a newly allocated string value.
+   *        Otherwise, the parameter's value is unmodified.
+   * @param aCheckMsg
+   *        Text to appear with the checkbox.  If null, check box will not be shown.
+   * @param aCheckState
+   *        Contains the initial checked state of the checkbox when this method
+   *        is called and the final checked state after this method returns.
+   *
+   * @return true for OK, false for Cancel.
+   */                        
+  boolean prompt(in mozIDOMWindowProxy aParent,
+                 in wstring aDialogTitle,
+                 in wstring aText,
+                 inout wstring aValue, 
+                 in wstring aCheckMsg,
+                 inout boolean aCheckState);
+
+  /**
+   * Puts up a dialog with an edit field, a password field, and an optional,
+   * labeled checkbox.
+   *
+   * @param aParent
+   *        The parent window or null.
+   * @param aDialogTitle
+   *        Text to appear in the title of the dialog.
+   * @param aText
+   *        Text to appear in the body of the dialog.
+   * @param aUsername
+   *        Contains the default value for the username field when this method
+   *        is called (null value is ok).  Upon return, if the user pressed OK,
+   *        then this parameter contains a newly allocated string value.
+   *        Otherwise, the parameter's value is unmodified.
+   * @param aPassword
+   *        Contains the default value for the password field when this method
+   *        is called (null value is ok).  Upon return, if the user pressed OK,
+   *        then this parameter contains a newly allocated string value.
+   *        Otherwise, the parameter's value is unmodified.
+   * @param aCheckMsg
+   *        Text to appear with the checkbox.  If null, check box will not be shown.
+   * @param aCheckState
+   *        Contains the initial checked state of the checkbox when this method
+   *        is called and the final checked state after this method returns.
+   *
+   * @return true for OK, false for Cancel.
+   */                        
+  boolean promptUsernameAndPassword(in mozIDOMWindowProxy aParent,
+                                    in wstring aDialogTitle,
+                                    in wstring aText,
+                                    inout wstring aUsername,
+                                    inout wstring aPassword,
+                                    in wstring aCheckMsg,
+                                    inout boolean aCheckState);
+
+  /**
+   * Puts up a dialog with a password field and an optional, labeled checkbox.
+   *
+   * @param aParent
+   *        The parent window or null.
+   * @param aDialogTitle
+   *        Text to appear in the title of the dialog.
+   * @param aText
+   *        Text to appear in the body of the dialog.
+   * @param aPassword
+   *        Contains the default value for the password field when this method
+   *        is called (null value is ok).  Upon return, if the user pressed OK,
+   *        then this parameter contains a newly allocated string value.
+   *        Otherwise, the parameter's value is unmodified.
+   * @param aCheckMsg
+   *        Text to appear with the checkbox.  If null, check box will not be shown.
+   * @param aCheckState
+   *        Contains the initial checked state of the checkbox when this method
+   *        is called and the final checked state after this method returns.
+   *
+   * @return true for OK, false for Cancel.
+   */                        
+  boolean promptPassword(in mozIDOMWindowProxy aParent,
+                         in wstring aDialogTitle,
+                         in wstring aText,
+                         inout wstring aPassword,
+                         in wstring aCheckMsg,
+                         inout boolean aCheckState);
+
+  /**
+   * Puts up a dialog box which has a list box of strings from which the user
+   * may make a single selection.
+   *
+   * @param aParent
+   *        The parent window or null.
+   * @param aDialogTitle
+   *        Text to appear in the title of the dialog.
+   * @param aText
+   *        Text to appear in the body of the dialog.
+   * @param aCount
+   *        The length of the aSelectList array parameter.
+   * @param aSelectList
+   *        The list of strings to display.
+   * @param aOutSelection
+   *        Contains the index of the selected item in the list when this
+   *        method returns true.
+   *
+   * @return true for OK, false for Cancel.
+   */                                                 
+  boolean select(in mozIDOMWindowProxy aParent,
+                 in wstring aDialogTitle,
+                 in wstring aText,
+                 in  uint32_t aCount,
+                 [array, size_is(aCount)] in wstring aSelectList,
+                 out long aOutSelection);
+};
diff --git a/embedding/components/windowwatcher/nsIPromptService2.idl b/embedding/components/windowwatcher/nsIPromptService2.idl
new file mode 100644
index 000000000..4afa0975b
--- /dev/null
+++ b/embedding/components/windowwatcher/nsIPromptService2.idl
@@ -0,0 +1,45 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIPromptService.idl"
+
+interface nsIAuthInformation;
+interface nsIAuthPromptCallback;
+interface nsICancelable;
+interface nsIChannel;
+interface mozIDOMWindowProxy;
+
+/**
+ * This is an improved version of nsIPromptService that is less prescriptive
+ * about the resulting user interface.
+ *
+ * @status INCOMPLETE do not freeze before fixing bug 228207
+ */
+[scriptable, uuid(3775ad32-8326-422b-9ff3-87ef1d3f9f0e)]
+interface nsIPromptService2 : nsIPromptService {
+  // NOTE: These functions differ from their nsIAuthPrompt counterparts by
+  // having additional checkbox parameters
+  // checkValue can be null meaning to show no checkbox
+  // checkboxLabel is a wstring so that it can be null from both JS and C++ in
+  // a convenient way
+  //
+  // See nsIAuthPrompt2 for documentation on the semantics of the other
+  // parameters.
+  boolean promptAuth(in mozIDOMWindowProxy aParent,
+                     in nsIChannel aChannel,
+                     in uint32_t level,
+                     in nsIAuthInformation authInfo,
+                     in wstring checkboxLabel,
+                     inout boolean checkValue);
+
+  nsICancelable asyncPromptAuth(in mozIDOMWindowProxy aParent,
+                                in nsIChannel aChannel,
+                                in nsIAuthPromptCallback aCallback,
+                                in nsISupports aContext,
+                                in uint32_t level,
+                                in nsIAuthInformation authInfo,
+                                in wstring checkboxLabel,
+                                inout boolean checkValue);
+};
+
diff --git a/embedding/components/windowwatcher/nsIWindowWatcher.idl b/embedding/components/windowwatcher/nsIWindowWatcher.idl
new file mode 100644
index 000000000..deea268c2
--- /dev/null
+++ b/embedding/components/windowwatcher/nsIWindowWatcher.idl
@@ -0,0 +1,167 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface mozIDOMWindowProxy;
+interface nsIObserver;
+interface nsIPrompt;
+interface nsIAuthPrompt;
+interface nsISimpleEnumerator;
+interface nsIWebBrowserChrome;
+interface nsIWindowCreator;
+
+
+
+/**
+ * nsIWindowWatcher is the keeper of Gecko/DOM Windows. It maintains
+ * a list of open top-level windows, and allows some operations on them.
+
+ * Usage notes:
+
+ *   This component has an |activeWindow| property. Clients may expect
+ * this property to be always current, so to properly integrate this component
+ * the application will need to keep it current by setting the property
+ * as the active window changes.
+ *   This component should not keep a (XPCOM) reference to any windows;
+ * the implementation will claim no ownership. Windows must notify
+ * this component when they are created or destroyed, so only a weak
+ * reference is kept. Note that there is no interface for such notifications
+ * (not a public one, anyway). This is taken care of both in Mozilla and
+ * by common embedding code. Embedding clients need do nothing special
+ * about that requirement.
+ *   This component must be initialized at application startup by calling
+ * setWindowCreator.
+ */
+[scriptable, uuid(641fe945-6902-4b3f-87c2-0daef32499b3)]
+interface nsIWindowWatcher : nsISupports {
+
+  /** Create a new window. It will automatically be added to our list
+      (via addWindow()).
+      @param aParent parent window, if any. Null if no parent.  If it is
+             impossible to get to an nsIWebBrowserChrome from aParent, this
+             method will effectively act as if aParent were null.
+      @param aURL url to which to open the new window. Must already be
+             escaped, if applicable. can be null.
+      @param aName window name from JS window.open. can be null.  If a window
+             with this name already exists, the openWindow call may just load
+             aUrl in it (if aUrl is not null) and return it.
+      @param aFeatures window features from JS window.open. can be null.
+      @param aArguments extra argument(s) to the new window, to be attached
+             as the |arguments| property. An nsIArray will be
+             unwound into multiple arguments (but not recursively!).
+             can be null.
+      @return the new window
+
+      @note This method may examine the JS context stack for purposes of
+            determining the security context to use for the search for a given
+            window named aName.
+      @note This method should try to set the default charset for the new
+            window to the default charset of aParent.  This is not guaranteed,
+            however.
+      @note This method may dispatch a "toplevel-window-ready" notification
+            via nsIObserverService if the window did not already exist.
+  */
+  mozIDOMWindowProxy openWindow(in mozIDOMWindowProxy aParent, in string aUrl,
+                                in string aName, in string aFeatures,
+                                in nsISupports aArguments);
+
+  /** Clients of this service can register themselves to be notified
+      when a window is opened or closed (added to or removed from this
+      service). This method adds an aObserver to the list of objects
+      to be notified.
+      @param aObserver the object to be notified when windows are
+                       opened or closed. Its Observe method will be
+                       called with the following parameters:
+
+      aObserver::Observe interprets its parameters so:
+      aSubject the window being opened or closed, sent as an nsISupports
+               which can be QIed to an nsIDOMWindow.
+      aTopic   a wstring, either "domwindowopened" or "domwindowclosed".
+      someData not used.
+  */
+  void registerNotification(in nsIObserver aObserver);
+
+  /** Clients of this service can register themselves to be notified
+      when a window is opened or closed (added to or removed from this
+      service). This method removes an aObserver from the list of objects
+      to be notified.
+      @param aObserver the observer to be removed.
+  */
+  void unregisterNotification(in nsIObserver aObserver);
+
+  /** Get an iterator for currently open windows in the order they were opened,
+      guaranteeing that each will be visited exactly once.
+      @return an enumerator which will itself return nsISupports objects which
+              can be QIed to an nsIDOMWindow
+  */
+
+  nsISimpleEnumerator getWindowEnumerator();
+
+  /** Return a newly created nsIPrompt implementation.
+      @param aParent the parent window used for posing alerts. can be null.
+      @return a new nsIPrompt object
+  */
+
+  nsIPrompt getNewPrompter(in mozIDOMWindowProxy aParent);
+
+  /** Return a newly created nsIAuthPrompt implementation.
+      @param aParent the parent window used for posing alerts. can be null.
+      @return a new nsIAuthPrompt object
+  */
+
+  nsIAuthPrompt getNewAuthPrompter(in mozIDOMWindowProxy aParent);
+
+  /** Set the window creator callback. It must be filled in by the app.
+      openWindow will use it to create new windows.
+      @param creator the callback. if null, the callback will be cleared
+                     and window creation capabilities lost.
+  */
+  void setWindowCreator(in nsIWindowCreator creator);
+
+  /** Returns true if a window creator callback has been set, false otherwise.
+  */
+  boolean hasWindowCreator();
+
+
+  /** Retrieve the chrome window mapped to the given DOM window. Window
+      Watcher keeps a list of all top-level DOM windows currently open,
+      along with their corresponding chrome interfaces. Since DOM Windows
+      lack a (public) means of retrieving their corresponding chrome,
+      this method will do that.
+      @param aWindow the DOM window whose chrome window the caller needs
+      @return the corresponding chrome window
+  */
+  nsIWebBrowserChrome getChromeForWindow(in mozIDOMWindowProxy aWindow);
+
+  /**
+      Retrieve an existing window (or frame).
+      @param aTargetName the window name
+      @param aCurrentWindow a starting point in the window hierarchy to
+                            begin the search.  If null, each toplevel window
+                            will be searched.
+
+      Note: This method will search all open windows for any window or
+      frame with the given window name. Make sure you understand the
+      security implications of this before using this method!
+  */
+  mozIDOMWindowProxy getWindowByName(in AString aTargetName,
+                                     in mozIDOMWindowProxy aCurrentWindow);
+
+  /** The Watcher serves as a global storage facility for the current active
+      (frontmost non-floating-palette-type) window, storing and returning
+      it on demand. Users must keep this attribute current, including after
+      the topmost window is closed. This attribute obviously can return null
+      if no windows are open, but should otherwise always return a valid
+      window.
+  */
+  attribute mozIDOMWindowProxy activeWindow;
+
+};
+
+%{C++
+#define NS_WINDOWWATCHER_CONTRACTID "@mozilla.org/embedcomp/window-watcher;1"
+%}
diff --git a/embedding/components/windowwatcher/nsPIPromptService.idl b/embedding/components/windowwatcher/nsPIPromptService.idl
new file mode 100644
index 000000000..32459b26b
--- /dev/null
+++ b/embedding/components/windowwatcher/nsPIPromptService.idl
@@ -0,0 +1,31 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* The general dialog posing function within nsPromptService, for
+   private consumption, only. */
+
+#include "nsISupports.idl"
+
+interface nsIDOMWindow;
+interface nsIDialogParamBlock;
+
+[uuid(C60A1955-6CB3-4827-8EF8-4F5C668AF0B3)]
+interface nsPIPromptService : nsISupports
+{
+%{C++
+  // eOpeningSound is obsolete but we need to support it for the compatibility.
+  // The implementers should use eSoundEventId instead.
+  enum {eMsg=0, eCheckboxMsg=1, eIconClass=2, eTitleMessage=3, eEditfield1Msg=4,
+        eEditfield2Msg=5, eEditfield1Value=6, eEditfield2Value=7,
+        eButton0Text=8, eButton1Text=9, eButton2Text=10, eButton3Text=11,
+        eDialogTitle=12, eOpeningSound=13};
+  enum {eButtonPressed=0, eCheckboxState=1, eNumberButtons=2,
+        eNumberEditfields=3, eEditField1Password=4, eDefaultButton=5,
+        eDelayButtonEnable=6, eSoundEventId=7};
+%}
+
+   void doDialog(in nsIDOMWindow aParent, in nsIDialogParamBlock aParamBlock, in string aChromeURL);
+};
+
diff --git a/embedding/components/windowwatcher/nsPIWindowWatcher.idl b/embedding/components/windowwatcher/nsPIWindowWatcher.idl
new file mode 100644
index 000000000..47b243364
--- /dev/null
+++ b/embedding/components/windowwatcher/nsPIWindowWatcher.idl
@@ -0,0 +1,146 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* Private "control" methods on the Window Watcher. These are annoying
+   bookkeeping methods, not part of the public (embedding) interface.
+*/
+
+#include "nsISupports.idl"
+
+interface mozIDOMWindowProxy;
+interface nsIDOMWindow;
+interface nsISimpleEnumerator;
+interface nsIWebBrowserChrome;
+interface nsIDocShellTreeItem;
+interface nsIArray;
+interface nsITabParent;
+interface nsIDocShellLoadInfo;
+
+[uuid(d162f9c4-19d5-4723-931f-f1e51bfa9f68)]
+
+interface nsPIWindowWatcher : nsISupports
+{
+  /** A window has been created. Add it to our list.
+      @param aWindow the window to add
+      @param aChrome the corresponding chrome window. The DOM window
+                     and chrome will be mapped together, and the corresponding
+                     chrome can be retrieved using the (not private)
+                     method getChromeForWindow. If null, any extant mapping
+                     will be cleared.
+  */
+  void addWindow(in mozIDOMWindowProxy aWindow,
+                 in nsIWebBrowserChrome aChrome);
+
+  /** A window has been closed. Remove it from our list.
+      @param aWindow the window to remove
+  */
+  void removeWindow(in mozIDOMWindowProxy aWindow);
+
+  /** Like the public interface's open(), but can handle openDialog-style
+      arguments and calls which shouldn't result in us navigating the window.
+
+      @param aParent parent window, if any. Null if no parent.  If it is
+             impossible to get to an nsIWebBrowserChrome from aParent, this
+             method will effectively act as if aParent were null.
+      @param aURL url to which to open the new window. Must already be
+             escaped, if applicable. can be null.
+      @param aName window name from JS window.open. can be null.  If a window
+             with this name already exists, the openWindow call may just load
+             aUrl in it (if aUrl is not null) and return it.
+      @param aFeatures window features from JS window.open. can be null.
+      @param aCalledFromScript true if we were called from script.
+      @param aDialog use dialog defaults (see nsIDOMWindow::openDialog)
+      @param aNavigate true if we should navigate the new window to the
+             specified URL.
+      @param aArgs Window argument
+      @param aIsPopupSpam true if the window is a popup spam window; used for
+                          popup blocker internals.
+      @param aForceNoOpener If true, force noopener behavior.  This means not
+                            looking for existing windows with the given name,
+                            not setting an opener on the newly opened window,
+                            and returning null from this method.
+      @param aLoadInfo if aNavigate is true, this allows the caller to pass in
+                       an nsIDocShellLoadInfo to use for the navigation.
+                       Callers can pass in null if they want the windowwatcher
+                       to just construct a loadinfo itself.  If aNavigate is
+                       false, this argument is ignored.
+
+      @return the new window
+
+      @note This method may examine the JS context stack for purposes of
+            determining the security context to use for the search for a given
+            window named aName.
+      @note This method should try to set the default charset for the new
+            window to the default charset of the document in the calling window
+            (which is determined based on the JS stack and the value of
+            aParent).  This is not guaranteed, however.
+  */
+  mozIDOMWindowProxy openWindow2(in mozIDOMWindowProxy aParent, in string aUrl,
+                                 in string aName, in string aFeatures,
+                                 in boolean aCalledFromScript,
+                                 in boolean aDialog,
+                                 in boolean aNavigate,
+                                 in nsISupports aArgs,
+                                 in boolean aIsPopupSpam,
+                                 in boolean aForceNoOpener,
+                                 in nsIDocShellLoadInfo aLoadInfo);
+
+  /**
+   * Opens a new window using the most recent non-private browser
+   * window as its parent.
+   *
+   * @return the nsITabParent of the initial browser for the newly opened
+   *         window.
+   */
+  nsITabParent openWindowWithoutParent();
+
+  /**
+   * Opens a new window so that the window that aOpeningTab belongs to
+   * is set as the parent window. The newly opened window will also
+   * inherit load context information from aOpeningTab.
+   *
+   * @param aOpeningTab
+   *        The nsITabParent that is requesting the new window be opened.
+   * @param aFeatures
+   *        Window features if called with window.open or similar.
+   * @param aCalledFromJS
+   *        True if called via window.open or similar.
+   * @param aOpenerFullZoom
+   *        The current zoom multiplier for the opener tab. This is then
+   *        applied to the newly opened window.
+   *
+   * @return the nsITabParent of the initial browser for the newly opened
+   *         window.
+   */
+  nsITabParent openWindowWithTabParent(in nsITabParent aOpeningTab,
+                                       in ACString aFeatures,
+                                       in boolean aCalledFromJS,
+                                       in float aOpenerFullZoom);
+
+  /**
+   * Find a named docshell tree item amongst all windows registered
+   * with the window watcher.  This may be a subframe in some window,
+   * for example.
+   *
+   * @param aName the name of the window.  Must not be null.
+   * @param aRequestor the tree item immediately making the request.
+   *        We should make sure to not recurse down into its findItemWithName
+   *        method.
+   * @param aOriginalRequestor the original treeitem that made the request.
+   *        Used for security checks.
+   * @return the tree item with aName as the name, or null if there
+   *         isn't one.  "Special" names, like _self, _top, etc, will be
+   *         treated specially only if aRequestor is null; in that case they
+   *         will be resolved relative to the first window the windowwatcher
+   *         knows about.
+   * @see findItemWithName methods on nsIDocShellTreeItem and
+   *      nsIDocShellTreeOwner
+   */
+  nsIDocShellTreeItem findItemWithName(in AString aName,
+                                       in nsIDocShellTreeItem aRequestor,
+                                       in nsIDocShellTreeItem aOriginalRequestor);
+};
+
diff --git a/embedding/components/windowwatcher/nsPromptUtils.h b/embedding/components/windowwatcher/nsPromptUtils.h
new file mode 100644
index 000000000..bd1267bef
--- /dev/null
+++ b/embedding/components/windowwatcher/nsPromptUtils.h
@@ -0,0 +1,141 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef NSPROMPTUTILS_H_
+#define NSPROMPTUTILS_H_
+
+#include "nsIHttpChannel.h"
+
+/**
+ * @file
+ * This file defines some helper functions that simplify interaction
+ * with authentication prompts.
+ */
+
+/**
+ * Given a username (possibly in DOMAIN\user form) and password, parses the
+ * domain out of the username if necessary and sets domain, username and
+ * password on the auth information object.
+ */
+inline void
+NS_SetAuthInfo(nsIAuthInformation* aAuthInfo, const nsString& aUser,
+               const nsString& aPassword)
+{
+  uint32_t flags;
+  aAuthInfo->GetFlags(&flags);
+  if (flags & nsIAuthInformation::NEED_DOMAIN) {
+    // Domain is separated from username by a backslash
+    int32_t idx = aUser.FindChar(char16_t('\\'));
+    if (idx == kNotFound) {
+      aAuthInfo->SetUsername(aUser);
+    } else {
+      aAuthInfo->SetDomain(Substring(aUser, 0, idx));
+      aAuthInfo->SetUsername(Substring(aUser, idx + 1));
+    }
+  } else {
+    aAuthInfo->SetUsername(aUser);
+  }
+  aAuthInfo->SetPassword(aPassword);
+}
+
+/**
+ * Gets the host and port from a channel and authentication info. This is the
+ * "logical" host and port for this authentication, i.e. for a proxy
+ * authentication it refers to the proxy, while for a host authentication it
+ * is the actual host.
+ *
+ * @param machineProcessing
+ *        When this parameter is true, the host will be returned in ASCII
+ *        (instead of UTF-8; this is relevant when IDN is used). In addition,
+ *        the port will be returned as the real port even when it was not
+ *        explicitly specified (when false, the port will be returned as -1 in
+ *        this case)
+ */
+inline void
+NS_GetAuthHostPort(nsIChannel* aChannel, nsIAuthInformation* aAuthInfo,
+                   bool aMachineProcessing, nsCString& aHost, int32_t* aPort)
+{
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = aChannel->GetURI(getter_AddRefs(uri));
+  if (NS_FAILED(rv)) {
+    return;
+  }
+
+  // Have to distinguish proxy auth and host auth here...
+  uint32_t flags;
+  aAuthInfo->GetFlags(&flags);
+  if (flags & nsIAuthInformation::AUTH_PROXY) {
+    nsCOMPtr<nsIProxiedChannel> proxied(do_QueryInterface(aChannel));
+    NS_ASSERTION(proxied, "proxy auth needs nsIProxiedChannel");
+
+    nsCOMPtr<nsIProxyInfo> info;
+    proxied->GetProxyInfo(getter_AddRefs(info));
+    NS_ASSERTION(info, "proxy auth needs nsIProxyInfo");
+
+    nsAutoCString idnhost;
+    info->GetHost(idnhost);
+    info->GetPort(aPort);
+
+    if (aMachineProcessing) {
+      nsCOMPtr<nsIIDNService> idnService =
+        do_GetService(NS_IDNSERVICE_CONTRACTID);
+      if (idnService) {
+        idnService->ConvertUTF8toACE(idnhost, aHost);
+      } else {
+        // Not much we can do here...
+        aHost = idnhost;
+      }
+    } else {
+      aHost = idnhost;
+    }
+  } else {
+    if (aMachineProcessing) {
+      uri->GetAsciiHost(aHost);
+      *aPort = NS_GetRealPort(uri);
+    } else {
+      uri->GetHost(aHost);
+      uri->GetPort(aPort);
+    }
+  }
+}
+
+/**
+ * Creates the key for looking up passwords in the password manager. This
+ * function uses the same format that Gecko functions have always used, thus
+ * ensuring backwards compatibility.
+ */
+inline void
+NS_GetAuthKey(nsIChannel* aChannel, nsIAuthInformation* aAuthInfo,
+              nsCString& aKey)
+{
+  // HTTP does this differently from other protocols
+  nsCOMPtr<nsIHttpChannel> http(do_QueryInterface(aChannel));
+  if (!http) {
+    nsCOMPtr<nsIURI> uri;
+    aChannel->GetURI(getter_AddRefs(uri));
+    uri->GetPrePath(aKey);
+    return;
+  }
+
+  // NOTE: For backwards-compatibility reasons, this must be the ASCII host.
+  nsCString host;
+  int32_t port = -1;
+
+  NS_GetAuthHostPort(aChannel, aAuthInfo, true, host, &port);
+
+  nsAutoString realm;
+  aAuthInfo->GetRealm(realm);
+
+  // Now assemble the key: host:port (realm)
+  aKey.Append(host);
+  aKey.Append(':');
+  aKey.AppendInt(port);
+  aKey.AppendLiteral(" (");
+  AppendUTF16toUTF8(realm, aKey);
+  aKey.Append(')');
+}
+
+#endif
diff --git a/embedding/components/windowwatcher/nsWindowWatcher.cpp b/embedding/components/windowwatcher/nsWindowWatcher.cpp
new file mode 100644
index 000000000..07872410e
--- /dev/null
+++ b/embedding/components/windowwatcher/nsWindowWatcher.cpp
@@ -0,0 +1,2610 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//#define USEWEAKREFS // (haven't quite figured that out yet)
+
+#include "nsWindowWatcher.h"
+#include "nsAutoWindowStateHelper.h"
+
+#include "nsCRT.h"
+#include "nsNetUtil.h"
+#include "nsIAuthPrompt.h"
+#include "nsIAuthPrompt2.h"
+#include "nsISimpleEnumerator.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsJSUtils.h"
+#include "plstr.h"
+
+#include "nsDocShell.h"
+#include "nsGlobalWindow.h"
+#include "nsIBaseWindow.h"
+#include "nsIBrowserDOMWindow.h"
+#include "nsIDocShell.h"
+#include "nsIDocShellLoadInfo.h"
+#include "nsIDocShellTreeItem.h"
+#include "nsIDocShellTreeOwner.h"
+#include "nsIDocumentLoader.h"
+#include "nsIDocument.h"
+#include "nsIDOMDocument.h"
+#include "nsIDOMWindow.h"
+#include "nsIDOMChromeWindow.h"
+#include "nsIDOMModalContentWindow.h"
+#include "nsIPrompt.h"
+#include "nsIScriptObjectPrincipal.h"
+#include "nsIScreen.h"
+#include "nsIScreenManager.h"
+#include "nsIScriptContext.h"
+#include "nsIObserverService.h"
+#include "nsIScriptSecurityManager.h"
+#include "nsXPCOM.h"
+#include "nsIURI.h"
+#include "nsIWebBrowser.h"
+#include "nsIWebBrowserChrome.h"
+#include "nsIWebNavigation.h"
+#include "nsIWindowCreator.h"
+#include "nsIWindowCreator2.h"
+#include "nsIXPConnect.h"
+#include "nsIXULRuntime.h"
+#include "nsPIDOMWindow.h"
+#include "nsIContentViewer.h"
+#include "nsIWindowProvider.h"
+#include "nsIMutableArray.h"
+#include "nsIDOMStorageManager.h"
+#include "nsIWidget.h"
+#include "nsFocusManager.h"
+#include "nsIPresShell.h"
+#include "nsPresContext.h"
+#include "nsContentUtils.h"
+#include "nsIPrefBranch.h"
+#include "nsIPrefService.h"
+#include "nsSandboxFlags.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/dom/DOMStorage.h"
+#include "mozilla/dom/ScriptSettings.h"
+#include "mozilla/dom/TabParent.h"
+#include "mozilla/dom/DocGroup.h"
+#include "mozilla/dom/TabGroup.h"
+#include "nsIXULWindow.h"
+#include "nsIXULBrowserWindow.h"
+#include "nsGlobalWindow.h"
+
+#ifdef USEWEAKREFS
+#include "nsIWeakReference.h"
+#endif
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+/****************************************************************
+ ******************** nsWatcherWindowEntry **********************
+ ****************************************************************/
+
+class nsWindowWatcher;
+
+struct nsWatcherWindowEntry
+{
+
+  nsWatcherWindowEntry(mozIDOMWindowProxy* aWindow, nsIWebBrowserChrome* aChrome)
+    : mChrome(nullptr)
+  {
+#ifdef USEWEAKREFS
+    mWindow = do_GetWeakReference(aWindow);
+#else
+    mWindow = aWindow;
+#endif
+    nsCOMPtr<nsISupportsWeakReference> supportsweak(do_QueryInterface(aChrome));
+    if (supportsweak) {
+      supportsweak->GetWeakReference(getter_AddRefs(mChromeWeak));
+    } else {
+      mChrome = aChrome;
+      mChromeWeak = nullptr;
+    }
+    ReferenceSelf();
+  }
+  ~nsWatcherWindowEntry() {}
+
+  void InsertAfter(nsWatcherWindowEntry* aOlder);
+  void Unlink();
+  void ReferenceSelf();
+
+#ifdef USEWEAKREFS
+  nsCOMPtr<nsIWeakReference> mWindow;
+#else // still not an owning ref
+  mozIDOMWindowProxy* mWindow;
+#endif
+  nsIWebBrowserChrome* mChrome;
+  nsWeakPtr mChromeWeak;
+  // each struct is in a circular, doubly-linked list
+  nsWatcherWindowEntry* mYounger; // next younger in sequence
+  nsWatcherWindowEntry* mOlder;
+};
+
+void
+nsWatcherWindowEntry::InsertAfter(nsWatcherWindowEntry* aOlder)
+{
+  if (aOlder) {
+    mOlder = aOlder;
+    mYounger = aOlder->mYounger;
+    mOlder->mYounger = this;
+    if (mOlder->mOlder == mOlder) {
+      mOlder->mOlder = this;
+    }
+    mYounger->mOlder = this;
+    if (mYounger->mYounger == mYounger) {
+      mYounger->mYounger = this;
+    }
+  }
+}
+
+void
+nsWatcherWindowEntry::Unlink()
+{
+  mOlder->mYounger = mYounger;
+  mYounger->mOlder = mOlder;
+  ReferenceSelf();
+}
+
+void
+nsWatcherWindowEntry::ReferenceSelf()
+{
+
+  mYounger = this;
+  mOlder = this;
+}
+
+/****************************************************************
+ ****************** nsWatcherWindowEnumerator *******************
+ ****************************************************************/
+
+class nsWatcherWindowEnumerator : public nsISimpleEnumerator
+{
+
+public:
+  explicit nsWatcherWindowEnumerator(nsWindowWatcher* aWatcher);
+  NS_IMETHOD HasMoreElements(bool* aResult) override;
+  NS_IMETHOD GetNext(nsISupports** aResult) override;
+
+  NS_DECL_ISUPPORTS
+
+protected:
+  virtual ~nsWatcherWindowEnumerator();
+
+private:
+  friend class nsWindowWatcher;
+
+  nsWatcherWindowEntry* FindNext();
+  void WindowRemoved(nsWatcherWindowEntry* aInfo);
+
+  nsWindowWatcher* mWindowWatcher;
+  nsWatcherWindowEntry* mCurrentPosition;
+};
+
+NS_IMPL_ADDREF(nsWatcherWindowEnumerator)
+NS_IMPL_RELEASE(nsWatcherWindowEnumerator)
+NS_IMPL_QUERY_INTERFACE(nsWatcherWindowEnumerator, nsISimpleEnumerator)
+
+nsWatcherWindowEnumerator::nsWatcherWindowEnumerator(nsWindowWatcher* aWatcher)
+  : mWindowWatcher(aWatcher)
+  , mCurrentPosition(aWatcher->mOldestWindow)
+{
+  mWindowWatcher->AddEnumerator(this);
+  mWindowWatcher->AddRef();
+}
+
+nsWatcherWindowEnumerator::~nsWatcherWindowEnumerator()
+{
+  mWindowWatcher->RemoveEnumerator(this);
+  mWindowWatcher->Release();
+}
+
+NS_IMETHODIMP
+nsWatcherWindowEnumerator::HasMoreElements(bool* aResult)
+{
+  if (!aResult) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  *aResult = !!mCurrentPosition;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWatcherWindowEnumerator::GetNext(nsISupports** aResult)
+{
+  if (!aResult) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  *aResult = nullptr;
+
+#ifdef USEWEAKREFS
+  while (mCurrentPosition) {
+    CallQueryReferent(mCurrentPosition->mWindow, aResult);
+    if (*aResult) {
+      mCurrentPosition = FindNext();
+      break;
+    } else { // window is gone!
+      mWindowWatcher->RemoveWindow(mCurrentPosition);
+    }
+  }
+  NS_IF_ADDREF(*aResult);
+#else
+  if (mCurrentPosition) {
+    CallQueryInterface(mCurrentPosition->mWindow, aResult);
+    mCurrentPosition = FindNext();
+  }
+#endif
+  return NS_OK;
+}
+
+nsWatcherWindowEntry*
+nsWatcherWindowEnumerator::FindNext()
+{
+  nsWatcherWindowEntry* info;
+
+  if (!mCurrentPosition) {
+    return 0;
+  }
+
+  info = mCurrentPosition->mYounger;
+  return info == mWindowWatcher->mOldestWindow ? 0 : info;
+}
+
+// if a window is being removed adjust the iterator's current position
+void
+nsWatcherWindowEnumerator::WindowRemoved(nsWatcherWindowEntry* aInfo)
+{
+
+  if (mCurrentPosition == aInfo) {
+    mCurrentPosition =
+      mCurrentPosition != aInfo->mYounger ? aInfo->mYounger : 0;
+  }
+}
+
+/****************************************************************
+ *********************** nsWindowWatcher ************************
+ ****************************************************************/
+
+NS_IMPL_ADDREF(nsWindowWatcher)
+NS_IMPL_RELEASE(nsWindowWatcher)
+NS_IMPL_QUERY_INTERFACE(nsWindowWatcher,
+                        nsIWindowWatcher,
+                        nsIPromptFactory,
+                        nsPIWindowWatcher)
+
+nsWindowWatcher::nsWindowWatcher()
+  : mEnumeratorList()
+  , mOldestWindow(0)
+  , mListLock("nsWindowWatcher.mListLock")
+{
+}
+
+nsWindowWatcher::~nsWindowWatcher()
+{
+  // delete data
+  while (mOldestWindow) {
+    RemoveWindow(mOldestWindow);
+  }
+}
+
+nsresult
+nsWindowWatcher::Init()
+{
+  return NS_OK;
+}
+
+/**
+ * Convert aArguments into either an nsIArray or nullptr.
+ *
+ *  - If aArguments is nullptr, return nullptr.
+ *  - If aArguments is an nsArray, return nullptr if it's empty, or otherwise
+ *    return the array.
+ *  - If aArguments is an nsIArray, return nullptr if it's empty, or
+ *    otherwise just return the array.
+ *  - Otherwise, return an nsIArray with one element: aArguments.
+ */
+static already_AddRefed<nsIArray>
+ConvertArgsToArray(nsISupports* aArguments)
+{
+  if (!aArguments) {
+    return nullptr;
+  }
+
+  nsCOMPtr<nsIArray> array = do_QueryInterface(aArguments);
+  if (array) {
+    uint32_t argc = 0;
+    array->GetLength(&argc);
+    if (argc == 0) {
+      return nullptr;
+    }
+
+    return array.forget();
+  }
+
+  nsCOMPtr<nsIMutableArray> singletonArray =
+    do_CreateInstance(NS_ARRAY_CONTRACTID);
+  NS_ENSURE_TRUE(singletonArray, nullptr);
+
+  nsresult rv = singletonArray->AppendElement(aArguments, /* aWeak = */ false);
+  NS_ENSURE_SUCCESS(rv, nullptr);
+
+  return singletonArray.forget();
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::OpenWindow(mozIDOMWindowProxy* aParent,
+                            const char* aUrl,
+                            const char* aName,
+                            const char* aFeatures,
+                            nsISupports* aArguments,
+                            mozIDOMWindowProxy** aResult)
+{
+  nsCOMPtr<nsIArray> argv = ConvertArgsToArray(aArguments);
+
+  uint32_t argc = 0;
+  if (argv) {
+    argv->GetLength(&argc);
+  }
+  bool dialog = (argc != 0);
+
+  return OpenWindowInternal(aParent, aUrl, aName, aFeatures,
+                            /* calledFromJS = */ false, dialog,
+                            /* navigate = */ true, argv,
+                            /* aIsPopupSpam = */ false,
+                            /* aForceNoOpener = */ false,
+                            /* aLoadInfo = */ nullptr,
+                            aResult);
+}
+
+struct SizeSpec
+{
+  SizeSpec()
+    : mLeft(0)
+    , mTop(0)
+    , mOuterWidth(0)
+    , mOuterHeight(0)
+    , mInnerWidth(0)
+    , mInnerHeight(0)
+    , mLeftSpecified(false)
+    , mTopSpecified(false)
+    , mOuterWidthSpecified(false)
+    , mOuterHeightSpecified(false)
+    , mInnerWidthSpecified(false)
+    , mInnerHeightSpecified(false)
+    , mUseDefaultWidth(false)
+    , mUseDefaultHeight(false)
+  {
+  }
+
+  int32_t mLeft;
+  int32_t mTop;
+  int32_t mOuterWidth;  // Total window width
+  int32_t mOuterHeight; // Total window height
+  int32_t mInnerWidth;  // Content area width
+  int32_t mInnerHeight; // Content area height
+
+  bool mLeftSpecified;
+  bool mTopSpecified;
+  bool mOuterWidthSpecified;
+  bool mOuterHeightSpecified;
+  bool mInnerWidthSpecified;
+  bool mInnerHeightSpecified;
+
+  // If these booleans are true, don't look at the corresponding width values
+  // even if they're specified -- they'll be bogus
+  bool mUseDefaultWidth;
+  bool mUseDefaultHeight;
+
+  bool PositionSpecified() const
+  {
+    return mLeftSpecified || mTopSpecified;
+  }
+
+  bool SizeSpecified() const
+  {
+    return mOuterWidthSpecified || mOuterHeightSpecified ||
+           mInnerWidthSpecified || mInnerHeightSpecified;
+  }
+};
+
+NS_IMETHODIMP
+nsWindowWatcher::OpenWindow2(mozIDOMWindowProxy* aParent,
+                             const char* aUrl,
+                             const char* aName,
+                             const char* aFeatures,
+                             bool aCalledFromScript,
+                             bool aDialog,
+                             bool aNavigate,
+                             nsISupports* aArguments,
+                             bool aIsPopupSpam,
+                             bool aForceNoOpener,
+                             nsIDocShellLoadInfo* aLoadInfo,
+                             mozIDOMWindowProxy** aResult)
+{
+  nsCOMPtr<nsIArray> argv = ConvertArgsToArray(aArguments);
+
+  uint32_t argc = 0;
+  if (argv) {
+    argv->GetLength(&argc);
+  }
+
+  // This is extremely messed up, but this behavior is necessary because
+  // callers lie about whether they're a dialog window and whether they're
+  // called from script.  Fixing this is bug 779939.
+  bool dialog = aDialog;
+  if (!aCalledFromScript) {
+    dialog = argc > 0;
+  }
+
+  return OpenWindowInternal(aParent, aUrl, aName, aFeatures,
+                            aCalledFromScript, dialog,
+                            aNavigate, argv, aIsPopupSpam,
+                            aForceNoOpener, aLoadInfo, aResult);
+}
+
+// This static function checks if the aDocShell uses an UserContextId equal to
+// the userContextId of subjectPrincipal, if not null.
+static bool
+CheckUserContextCompatibility(nsIDocShell* aDocShell)
+{
+  MOZ_ASSERT(aDocShell);
+
+  uint32_t userContextId =
+    static_cast<nsDocShell*>(aDocShell)->GetOriginAttributes().mUserContextId;
+
+  nsCOMPtr<nsIPrincipal> subjectPrincipal =
+    nsContentUtils::GetCurrentJSContext()
+      ? nsContentUtils::SubjectPrincipal() : nullptr;
+
+  // If we don't have a valid principal, probably we are in e10s mode, parent
+  // side.
+  if (!subjectPrincipal) {
+    return true;
+  }
+
+  // DocShell can have UsercontextID set but loading a document with system
+  // principal. In this case, we consider everything ok.
+  if (nsContentUtils::IsSystemPrincipal(subjectPrincipal)) {
+    return true;
+  }
+
+  return subjectPrincipal->GetUserContextId() == userContextId;
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::OpenWindowWithoutParent(nsITabParent** aResult)
+{
+  return OpenWindowWithTabParent(nullptr, EmptyCString(), true, 1.0f, aResult);
+}
+
+nsresult
+nsWindowWatcher::CreateChromeWindow(const nsACString& aFeatures,
+                                    nsIWebBrowserChrome* aParentChrome,
+                                    uint32_t aChromeFlags,
+                                    uint32_t aContextFlags,
+                                    nsITabParent* aOpeningTabParent,
+                                    mozIDOMWindowProxy* aOpener,
+                                    nsIWebBrowserChrome** aResult)
+{
+  nsCOMPtr<nsIWindowCreator2> windowCreator2(do_QueryInterface(mWindowCreator));
+  if (NS_WARN_IF(!windowCreator2)) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  // B2G multi-screen support. mozDisplayId is returned from the
+  // "display-changed" event, it is also platform-dependent.
+#ifdef MOZ_WIDGET_GONK
+  int retval = WinHasOption(aFeatures, "mozDisplayId", 0, nullptr);
+  windowCreator2->SetScreenId(retval);
+#endif
+
+  bool cancel = false;
+  nsCOMPtr<nsIWebBrowserChrome> newWindowChrome;
+  nsresult rv =
+    windowCreator2->CreateChromeWindow2(aParentChrome, aChromeFlags, aContextFlags,
+                                        aOpeningTabParent, aOpener, &cancel,
+                                        getter_AddRefs(newWindowChrome));
+
+  if (NS_SUCCEEDED(rv) && cancel) {
+    newWindowChrome = nullptr;
+    return NS_ERROR_ABORT;
+  }
+
+  newWindowChrome.forget(aResult);
+  return NS_OK;
+}
+
+/**
+ * Disable persistence of size/position in popups (determined by
+ * determining whether the features parameter specifies width or height
+ * in any way). We consider any overriding of the window's size or position
+ * in the open call as disabling persistence of those attributes.
+ * Popup windows (which should not persist size or position) generally set
+ * the size.
+ *
+ * @param aFeatures
+ *        The features string that was used to open the window.
+ * @param aTreeOwner
+ *        The nsIDocShellTreeOwner of the newly opened window. If null,
+ *        this function is a no-op.
+ */
+void
+nsWindowWatcher::MaybeDisablePersistence(const nsACString& aFeatures,
+                                         nsIDocShellTreeOwner* aTreeOwner)
+{
+  if (!aTreeOwner) {
+    return;
+  }
+
+ // At the moment, the strings "height=" or "width=" never happen
+ // outside a size specification, so we can do this the Q&D way.
+  if (PL_strcasestr(aFeatures.BeginReading(), "width=") ||
+      PL_strcasestr(aFeatures.BeginReading(), "height=")) {
+    aTreeOwner->SetPersistence(false, false, false);
+  }
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::OpenWindowWithTabParent(nsITabParent* aOpeningTabParent,
+                                         const nsACString& aFeatures,
+                                         bool aCalledFromJS,
+                                         float aOpenerFullZoom,
+                                         nsITabParent** aResult)
+{
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(mWindowCreator);
+
+  if (!nsContentUtils::IsSafeToRunScript()) {
+    nsContentUtils::WarnScriptWasIgnored(nullptr);
+    return NS_ERROR_FAILURE;
+  }
+
+  if (NS_WARN_IF(!mWindowCreator)) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  bool isPrivateBrowsingWindow =
+    Preferences::GetBool("browser.privatebrowsing.autostart");
+
+  nsCOMPtr<nsPIDOMWindowOuter> parentWindowOuter;
+  if (aOpeningTabParent) {
+    // We need to examine the window that aOpeningTabParent belongs to in
+    // order to inform us of what kind of window we're going to open.
+    TabParent* openingTab = TabParent::GetFrom(aOpeningTabParent);
+    parentWindowOuter = openingTab->GetParentWindowOuter();
+
+    // Propagate the privacy status of the parent window, if
+    // available, to the child.
+    if (!isPrivateBrowsingWindow) {
+      nsCOMPtr<nsILoadContext> parentContext = openingTab->GetLoadContext();
+      if (parentContext) {
+        isPrivateBrowsingWindow = parentContext->UsePrivateBrowsing();
+      }
+    }
+  }
+
+  if (!parentWindowOuter) {
+    // We couldn't find a browser window for the opener, so either we
+    // never were passed aOpeningTabParent, the window is closed,
+    // or it's in the process of closing. Either way, we'll use
+    // the most recently opened browser window instead.
+    parentWindowOuter = nsContentUtils::GetMostRecentNonPBWindow();
+  }
+
+  if (NS_WARN_IF(!parentWindowOuter)) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsCOMPtr<nsIDocShellTreeOwner> parentTreeOwner;
+  GetWindowTreeOwner(parentWindowOuter, getter_AddRefs(parentTreeOwner));
+  if (NS_WARN_IF(!parentTreeOwner)) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsCOMPtr<nsIWindowCreator2> windowCreator2(do_QueryInterface(mWindowCreator));
+  if (NS_WARN_IF(!windowCreator2)) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  uint32_t contextFlags = 0;
+  if (parentWindowOuter->IsLoadingOrRunningTimeout()) {
+    contextFlags |=
+            nsIWindowCreator2::PARENT_IS_LOADING_OR_RUNNING_TIMEOUT;
+  }
+
+  uint32_t chromeFlags = CalculateChromeFlagsForChild(aFeatures);
+
+  // A content process has asked for a new window, which implies
+  // that the new window will need to be remote.
+  chromeFlags |= nsIWebBrowserChrome::CHROME_REMOTE_WINDOW;
+
+  nsCOMPtr<nsIWebBrowserChrome> parentChrome(do_GetInterface(parentTreeOwner));
+  nsCOMPtr<nsIWebBrowserChrome> newWindowChrome;
+
+  CreateChromeWindow(aFeatures, parentChrome, chromeFlags, contextFlags,
+                     aOpeningTabParent, nullptr, getter_AddRefs(newWindowChrome));
+
+  if (NS_WARN_IF(!newWindowChrome)) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsCOMPtr<nsIDocShellTreeItem> chromeTreeItem = do_GetInterface(newWindowChrome);
+  if (NS_WARN_IF(!chromeTreeItem)) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsCOMPtr<nsIDocShellTreeOwner> chromeTreeOwner;
+  chromeTreeItem->GetTreeOwner(getter_AddRefs(chromeTreeOwner));
+  if (NS_WARN_IF(!chromeTreeOwner)) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsCOMPtr<nsILoadContext> chromeContext = do_QueryInterface(chromeTreeItem);
+  if (NS_WARN_IF(!chromeContext)) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  chromeContext->SetPrivateBrowsing(isPrivateBrowsingWindow);
+
+  // Tabs opened from a content process can only open new windows
+  // that will also run with out-of-process tabs.
+  chromeContext->SetRemoteTabs(true);
+
+  MaybeDisablePersistence(aFeatures, chromeTreeOwner);
+
+  SizeSpec sizeSpec;
+  CalcSizeSpec(aFeatures, sizeSpec);
+  SizeOpenedWindow(chromeTreeOwner, parentWindowOuter, false, sizeSpec,
+                   Some(aOpenerFullZoom));
+
+  nsCOMPtr<nsITabParent> newTabParent;
+  chromeTreeOwner->GetPrimaryTabParent(getter_AddRefs(newTabParent));
+  if (NS_WARN_IF(!newTabParent)) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  newTabParent.forget(aResult);
+  return NS_OK;
+}
+
+nsresult
+nsWindowWatcher::OpenWindowInternal(mozIDOMWindowProxy* aParent,
+                                    const char* aUrl,
+                                    const char* aName,
+                                    const char* aFeatures,
+                                    bool aCalledFromJS,
+                                    bool aDialog,
+                                    bool aNavigate,
+                                    nsIArray* aArgv,
+                                    bool aIsPopupSpam,
+                                    bool aForceNoOpener,
+                                    nsIDocShellLoadInfo* aLoadInfo,
+                                    mozIDOMWindowProxy** aResult)
+{
+  nsresult rv = NS_OK;
+  bool isNewToplevelWindow = false;
+  bool windowIsNew = false;
+  bool windowNeedsName = false;
+  bool windowIsModal = false;
+  bool uriToLoadIsChrome = false;
+  bool windowIsModalContentDialog = false;
+
+  uint32_t chromeFlags;
+  nsAutoString name;          // string version of aName
+  nsAutoCString features;     // string version of aFeatures
+  nsCOMPtr<nsIURI> uriToLoad; // from aUrl, if any
+  nsCOMPtr<nsIDocShellTreeOwner> parentTreeOwner; // from the parent window, if any
+  nsCOMPtr<nsIDocShellTreeItem> newDocShellItem; // from the new window
+
+  nsCOMPtr<nsPIDOMWindowOuter> parent =
+    aParent ? nsPIDOMWindowOuter::From(aParent) : nullptr;
+
+  NS_ENSURE_ARG_POINTER(aResult);
+  *aResult = 0;
+
+  if (!nsContentUtils::IsSafeToRunScript()) {
+    nsContentUtils::WarnScriptWasIgnored(nullptr);
+    return NS_ERROR_FAILURE;
+  }
+
+  GetWindowTreeOwner(parent, getter_AddRefs(parentTreeOwner));
+
+  // We expect TabParent to have provided us the absolute URI of the window
+  // we're to open, so there's no need to call URIfromURL (or more importantly,
+  // to check for a chrome URI, which cannot be opened from a remote tab).
+  if (aUrl) {
+    rv = URIfromURL(aUrl, aParent, getter_AddRefs(uriToLoad));
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+    uriToLoad->SchemeIs("chrome", &uriToLoadIsChrome);
+  }
+
+  bool nameSpecified = false;
+  if (aName) {
+    CopyUTF8toUTF16(aName, name);
+    nameSpecified = true;
+  } else {
+    name.SetIsVoid(true);
+  }
+
+  if (aFeatures) {
+    features.Assign(aFeatures);
+    features.StripWhitespace();
+  } else {
+    features.SetIsVoid(true);
+  }
+
+  // try to find an extant window with the given name
+  nsCOMPtr<nsPIDOMWindowOuter> foundWindow =
+    SafeGetWindowByName(name, aForceNoOpener, aParent);
+  GetWindowTreeItem(foundWindow, getter_AddRefs(newDocShellItem));
+
+  // Do sandbox checks here, instead of waiting until nsIDocShell::LoadURI.
+  // The state of the window can change before this call and if we are blocked
+  // because of sandboxing, we wouldn't want that to happen.
+  nsCOMPtr<nsPIDOMWindowOuter> parentWindow =
+    aParent ? nsPIDOMWindowOuter::From(aParent) : nullptr;
+  nsCOMPtr<nsIDocShell> parentDocShell;
+  if (parentWindow) {
+    parentDocShell = parentWindow->GetDocShell();
+    if (parentDocShell) {
+      nsCOMPtr<nsIDocShell> foundDocShell = do_QueryInterface(newDocShellItem);
+      if (parentDocShell->IsSandboxedFrom(foundDocShell)) {
+        return NS_ERROR_DOM_INVALID_ACCESS_ERR;
+      }
+    }
+  }
+
+  // no extant window? make a new one.
+
+  // If no parent, consider it chrome when running in the parent process.
+  bool hasChromeParent = XRE_IsContentProcess() ? false : true;
+  if (aParent) {
+    // Check if the parent document has chrome privileges.
+    nsIDocument* doc = parentWindow->GetDoc();
+    hasChromeParent = doc && nsContentUtils::IsChromeDoc(doc);
+  }
+
+  bool isCallerChrome = nsContentUtils::LegacyIsCallerChromeOrNativeCode();
+
+  // Make sure we calculate the chromeFlags *before* we push the
+  // callee context onto the context stack so that
+  // the calculation sees the actual caller when doing its
+  // security checks.
+  if (isCallerChrome && XRE_IsParentProcess()) {
+    chromeFlags = CalculateChromeFlagsForParent(aParent, features,
+                                                aDialog, uriToLoadIsChrome,
+                                                hasChromeParent, aCalledFromJS);
+  } else {
+    chromeFlags = CalculateChromeFlagsForChild(features);
+
+    // Until ShowModalDialog is removed, it's still possible for content to
+    // request dialogs, but only in single-process mode.
+    if (aDialog) {
+      MOZ_ASSERT(XRE_IsParentProcess());
+      chromeFlags |= nsIWebBrowserChrome::CHROME_OPENAS_DIALOG;
+    }
+  }
+
+  // If we're not called through our JS version of the API, and we got
+  // our internal modal option, treat the window we're opening as a
+  // modal content window (and set the modal chrome flag).
+  if (!aCalledFromJS && aArgv &&
+      WinHasOption(features, "-moz-internal-modal", 0, nullptr)) {
+    windowIsModalContentDialog = true;
+
+    // CHROME_MODAL gets inherited by dependent windows, which affects various
+    // platform-specific window state (especially on OSX). So we need some way
+    // to determine that this window was actually opened by nsGlobalWindow::
+    // ShowModalDialog(), and that somebody is actually going to be watching
+    // for return values and all that.
+    chromeFlags |= nsIWebBrowserChrome::CHROME_MODAL_CONTENT_WINDOW;
+    chromeFlags |= nsIWebBrowserChrome::CHROME_MODAL;
+  }
+
+  SizeSpec sizeSpec;
+  CalcSizeSpec(features, sizeSpec);
+
+  nsCOMPtr<nsIScriptSecurityManager> sm(
+    do_GetService(NS_SCRIPTSECURITYMANAGER_CONTRACTID));
+
+
+  // XXXbz Why is an AutoJSAPI good enough here?  Wouldn't AutoEntryScript (so
+  // we affect the entry global) make more sense?  Or do we just want to affect
+  // GetSubjectPrincipal()?
+  dom::AutoJSAPI jsapiChromeGuard;
+
+  bool windowTypeIsChrome =
+    chromeFlags & nsIWebBrowserChrome::CHROME_OPENAS_CHROME;
+  if (isCallerChrome && !hasChromeParent && !windowTypeIsChrome) {
+    // open() is called from chrome on a non-chrome window, initialize an
+    // AutoJSAPI with the callee to prevent the caller's privileges from leaking
+    // into code that runs while opening the new window.
+    //
+    // The reasoning for this is in bug 289204. Basically, chrome sometimes does
+    // someContentWindow.open(untrustedURL), and wants to be insulated from nasty
+    // javascript: URLs and such. But there are also cases where we create a
+    // window parented to a content window (such as a download dialog), usually
+    // directly with nsIWindowWatcher. In those cases, we want the principal of
+    // the initial about:blank document to be system, so that the subsequent XUL
+    // load can reuse the inner window and avoid blowing away expandos. As such,
+    // we decide whether to load with the principal of the caller or of the parent
+    // based on whether the docshell type is chrome or content.
+
+    nsCOMPtr<nsIGlobalObject> parentGlobalObject = do_QueryInterface(aParent);
+    if (!aParent) {
+      jsapiChromeGuard.Init();
+    } else if (NS_WARN_IF(!jsapiChromeGuard.Init(parentGlobalObject))) {
+      return NS_ERROR_UNEXPECTED;
+    }
+  }
+
+  uint32_t activeDocsSandboxFlags = 0;
+  if (!newDocShellItem) {
+    // We're going to either open up a new window ourselves or ask a
+    // nsIWindowProvider for one.  In either case, we'll want to set the right
+    // name on it.
+    windowNeedsName = true;
+
+    // If the parent trying to open a new window is sandboxed
+    // without 'allow-popups', this is not allowed and we fail here.
+    if (aParent) {
+      if (nsIDocument* doc = parentWindow->GetDoc()) {
+        // Save sandbox flags for copying to new browsing context (docShell).
+        activeDocsSandboxFlags = doc->GetSandboxFlags();
+        if (activeDocsSandboxFlags & SANDBOXED_AUXILIARY_NAVIGATION) {
+          return NS_ERROR_DOM_INVALID_ACCESS_ERR;
+        }
+      }
+    }
+
+    // Now check whether it's ok to ask a window provider for a window.  Don't
+    // do it if we're opening a dialog or if our parent is a chrome window or
+    // if we're opening something that has modal, dialog, or chrome flags set.
+    nsCOMPtr<nsIDOMChromeWindow> chromeWin = do_QueryInterface(aParent);
+    if (!aDialog && !chromeWin &&
+        !(chromeFlags & (nsIWebBrowserChrome::CHROME_MODAL |
+                         nsIWebBrowserChrome::CHROME_OPENAS_DIALOG |
+                         nsIWebBrowserChrome::CHROME_OPENAS_CHROME))) {
+      nsCOMPtr<nsIWindowProvider> provider;
+      if (parentTreeOwner) {
+        provider = do_GetInterface(parentTreeOwner);
+      } else if (XRE_IsContentProcess()) {
+        // we're in a content process but we don't have a tabchild we can
+        // use.
+        provider = nsContentUtils::GetWindowProviderForContentProcess();
+      }
+
+      if (provider) {
+        nsCOMPtr<mozIDOMWindowProxy> newWindow;
+        rv = provider->ProvideWindow(aParent, chromeFlags, aCalledFromJS,
+                                     sizeSpec.PositionSpecified(),
+                                     sizeSpec.SizeSpecified(),
+                                     uriToLoad, name, features, aForceNoOpener,
+                                     &windowIsNew, getter_AddRefs(newWindow));
+
+        if (NS_SUCCEEDED(rv)) {
+          GetWindowTreeItem(newWindow, getter_AddRefs(newDocShellItem));
+          if (windowIsNew && newDocShellItem) {
+            // Make sure to stop any loads happening in this window that the
+            // window provider might have started.  Otherwise if our caller
+            // manipulates the window it just opened and then the load
+            // completes their stuff will get blown away.
+            nsCOMPtr<nsIWebNavigation> webNav =
+              do_QueryInterface(newDocShellItem);
+            webNav->Stop(nsIWebNavigation::STOP_NETWORK);
+          }
+
+          // If this is a new window, but it's incompatible with the current
+          // userContextId, we ignore it and we pretend that nothing has been
+          // returned by ProvideWindow.
+          if (!windowIsNew && newDocShellItem) {
+            nsCOMPtr<nsIDocShell> docShell = do_QueryInterface(newDocShellItem);
+            if (!CheckUserContextCompatibility(docShell)) {
+              newWindow = nullptr;
+              newDocShellItem = nullptr;
+              windowIsNew = false;
+            }
+          }
+
+        } else if (rv == NS_ERROR_ABORT) {
+          // NS_ERROR_ABORT means the window provider has flat-out rejected
+          // the open-window call and we should bail.  Don't return an error
+          // here, because our caller may propagate that error, which might
+          // cause e.g. window.open to throw!  Just return null for our out
+          // param.
+          return NS_OK;
+        }
+      }
+    }
+  }
+
+  bool newWindowShouldBeModal = false;
+  bool parentIsModal = false;
+  if (!newDocShellItem) {
+    windowIsNew = true;
+    isNewToplevelWindow = true;
+
+    nsCOMPtr<nsIWebBrowserChrome> parentChrome(do_GetInterface(parentTreeOwner));
+
+    // is the parent (if any) modal? if so, we must be, too.
+    bool weAreModal = (chromeFlags & nsIWebBrowserChrome::CHROME_MODAL) != 0;
+    newWindowShouldBeModal = weAreModal;
+    if (!weAreModal && parentChrome) {
+      parentChrome->IsWindowModal(&weAreModal);
+      parentIsModal = weAreModal;
+    }
+
+    if (weAreModal) {
+      windowIsModal = true;
+      // in case we added this because weAreModal
+      chromeFlags |= nsIWebBrowserChrome::CHROME_MODAL |
+                     nsIWebBrowserChrome::CHROME_DEPENDENT;
+    }
+
+    // Make sure to not create modal windows if our parent is invisible and
+    // isn't a chrome window.  Otherwise we can end up in a bizarre situation
+    // where we can't shut down because an invisible window is open.  If
+    // someone tries to do this, throw.
+    if (!hasChromeParent && (chromeFlags & nsIWebBrowserChrome::CHROME_MODAL)) {
+      nsCOMPtr<nsIBaseWindow> parentWindow(do_GetInterface(parentTreeOwner));
+      nsCOMPtr<nsIWidget> parentWidget;
+      if (parentWindow) {
+        parentWindow->GetMainWidget(getter_AddRefs(parentWidget));
+      }
+      // NOTE: the logic for this visibility check is duplicated in
+      // nsIDOMWindowUtils::isParentWindowMainWidgetVisible - if we change
+      // how a window is determined "visible" in this context then we should
+      // also adjust that attribute and/or any consumers of it...
+      if (parentWidget && !parentWidget->IsVisible()) {
+        return NS_ERROR_NOT_AVAILABLE;
+      }
+    }
+
+    NS_ASSERTION(mWindowCreator,
+                 "attempted to open a new window with no WindowCreator");
+    rv = NS_ERROR_FAILURE;
+    if (mWindowCreator) {
+      nsCOMPtr<nsIWebBrowserChrome> newChrome;
+
+      nsCOMPtr<nsPIDOMWindowInner> parentTopInnerWindow;
+      if (parentWindow) {
+        nsCOMPtr<nsPIDOMWindowOuter> parentTopWindow = parentWindow->GetTop();
+        if (parentTopWindow) {
+          parentTopInnerWindow = parentTopWindow->GetCurrentInnerWindow();
+        }
+      }
+
+      if (parentTopInnerWindow) {
+        parentTopInnerWindow->Suspend();
+      }
+
+      /* If the window creator is an nsIWindowCreator2, we can give it
+         some hints. The only hint at this time is whether the opening window
+         is in a situation that's likely to mean this is an unrequested
+         popup window we're creating. However we're not completely honest:
+         we clear that indicator if the opener is chrome, so that the
+         downstream consumer can treat the indicator to mean simply
+         that the new window is subject to popup control. */
+      nsCOMPtr<nsIWindowCreator2> windowCreator2(
+        do_QueryInterface(mWindowCreator));
+      if (windowCreator2) {
+        uint32_t contextFlags = 0;
+        bool popupConditions = false;
+
+        // is the parent under popup conditions?
+        if (parentWindow) {
+          popupConditions = parentWindow->IsLoadingOrRunningTimeout();
+        }
+
+        // chrome is always allowed, so clear the flag if the opener is chrome
+        if (popupConditions) {
+          popupConditions = !isCallerChrome;
+        }
+
+        if (popupConditions) {
+          contextFlags |=
+            nsIWindowCreator2::PARENT_IS_LOADING_OR_RUNNING_TIMEOUT;
+        }
+
+        mozIDOMWindowProxy* openerWindow = aForceNoOpener ? nullptr : aParent;
+        rv = CreateChromeWindow(features, parentChrome, chromeFlags, contextFlags,
+                                nullptr, openerWindow, getter_AddRefs(newChrome));
+
+      } else {
+        rv = mWindowCreator->CreateChromeWindow(parentChrome, chromeFlags,
+                                                getter_AddRefs(newChrome));
+      }
+
+      if (parentTopInnerWindow) {
+        parentTopInnerWindow->Resume();
+      }
+
+      if (newChrome) {
+        nsCOMPtr<nsIXULWindow> xulWin = do_GetInterface(newChrome);
+        if (xulWin) {
+          nsCOMPtr<nsIXULBrowserWindow> xulBrowserWin;
+          xulWin->GetXULBrowserWindow(getter_AddRefs(xulBrowserWin));
+          if (xulBrowserWin) {
+            nsPIDOMWindowOuter* openerWindow = aForceNoOpener ? nullptr : parentWindow.get();
+            xulBrowserWin->ForceInitialBrowserNonRemote(openerWindow);
+          }
+        }
+        /* It might be a chrome nsXULWindow, in which case it won't have
+            an nsIDOMWindow (primary content shell). But in that case, it'll
+            be able to hand over an nsIDocShellTreeItem directly. */
+        nsCOMPtr<nsPIDOMWindowOuter> newWindow(do_GetInterface(newChrome));
+        if (newWindow) {
+          GetWindowTreeItem(newWindow, getter_AddRefs(newDocShellItem));
+        }
+        if (!newDocShellItem) {
+          newDocShellItem = do_GetInterface(newChrome);
+        }
+        if (!newDocShellItem) {
+          rv = NS_ERROR_FAILURE;
+        }
+      }
+    }
+  }
+
+  // better have a window to use by this point
+  if (!newDocShellItem) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIDocShell> newDocShell(do_QueryInterface(newDocShellItem));
+  NS_ENSURE_TRUE(newDocShell, NS_ERROR_UNEXPECTED);
+
+  // If our parent is sandboxed, set it as the one permitted sandboxed navigator
+  // on the new window we're opening.
+  if (activeDocsSandboxFlags && parentWindow) {
+    newDocShell->SetOnePermittedSandboxedNavigator(
+      parentWindow->GetDocShell());
+  }
+
+  // Copy sandbox flags to the new window if activeDocsSandboxFlags says to do
+  // so.  Note that it's only nonzero if the window is new, so clobbering
+  // sandbox flags on the window makes sense in that case.
+  if (activeDocsSandboxFlags &
+        SANDBOX_PROPAGATES_TO_AUXILIARY_BROWSING_CONTEXTS) {
+    newDocShell->SetSandboxFlags(activeDocsSandboxFlags);
+  }
+
+  rv = ReadyOpenedDocShellItem(newDocShellItem, parentWindow, windowIsNew,
+                               aForceNoOpener, aResult);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  if (isNewToplevelWindow) {
+    nsCOMPtr<nsIDocShellTreeOwner> newTreeOwner;
+    newDocShellItem->GetTreeOwner(getter_AddRefs(newTreeOwner));
+    MaybeDisablePersistence(features, newTreeOwner);
+  }
+
+  if ((aDialog || windowIsModalContentDialog) && aArgv) {
+    // Set the args on the new window.
+    nsCOMPtr<nsPIDOMWindowOuter> piwin(do_QueryInterface(*aResult));
+    NS_ENSURE_TRUE(piwin, NS_ERROR_UNEXPECTED);
+
+    rv = piwin->SetArguments(aArgv);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  /* allow a window that we found by name to keep its name (important for cases
+     like _self where the given name is different (and invalid)).  Also, _blank
+     is not a window name. */
+  if (windowNeedsName) {
+    if (nameSpecified && !name.LowerCaseEqualsLiteral("_blank")) {
+      newDocShellItem->SetName(name);
+    } else {
+      newDocShellItem->SetName(EmptyString());
+    }
+  }
+
+  // Now we have to set the right opener principal on the new window.  Note
+  // that we have to do this _before_ starting any URI loads, thanks to the
+  // sync nature of javascript: loads.
+  //
+  // Note: The check for the current JSContext isn't necessarily sensical.
+  // It's just designed to preserve old semantics during a mass-conversion
+  // patch.
+  nsCOMPtr<nsIPrincipal> subjectPrincipal =
+    nsContentUtils::GetCurrentJSContext() ? nsContentUtils::SubjectPrincipal() :
+                                            nullptr;
+
+  bool isPrivateBrowsingWindow = false;
+
+  if (windowIsNew) {
+    auto* docShell = static_cast<nsDocShell*>(newDocShell.get());
+
+    // If this is not a chrome docShell, we apply originAttributes from the
+    // subjectPrincipal unless if it's an expanded or system principal.
+    if (subjectPrincipal &&
+        !nsContentUtils::IsSystemOrExpandedPrincipal(subjectPrincipal) &&
+        docShell->ItemType() != nsIDocShellTreeItem::typeChrome) {
+      DocShellOriginAttributes attrs;
+      attrs.InheritFromDocToChildDocShell(BasePrincipal::Cast(subjectPrincipal)->OriginAttributesRef());
+      isPrivateBrowsingWindow = !!attrs.mPrivateBrowsingId;
+      docShell->SetOriginAttributes(attrs);
+    } else {
+      nsCOMPtr<nsIDocShellTreeItem> parentItem;
+      GetWindowTreeItem(aParent, getter_AddRefs(parentItem));
+      nsCOMPtr<nsILoadContext> parentContext = do_QueryInterface(parentItem);
+      if (parentContext) {
+        isPrivateBrowsingWindow = parentContext->UsePrivateBrowsing();
+      }
+    }
+
+    bool autoPrivateBrowsing =
+      Preferences::GetBool("browser.privatebrowsing.autostart");
+
+    if (!autoPrivateBrowsing &&
+        (chromeFlags & nsIWebBrowserChrome::CHROME_NON_PRIVATE_WINDOW)) {
+      isPrivateBrowsingWindow = false;
+    } else if (autoPrivateBrowsing ||
+               (chromeFlags & nsIWebBrowserChrome::CHROME_PRIVATE_WINDOW)) {
+      isPrivateBrowsingWindow = true;
+    }
+
+    // Now set the opener principal on the new window.  Note that we need to do
+    // this no matter whether we were opened from JS; if there is nothing on
+    // the JS stack, just use the principal of our parent window.  In those
+    // cases we do _not_ set the parent window principal as the owner of the
+    // load--since we really don't know who the owner is, just leave it null.
+    nsCOMPtr<nsPIDOMWindowOuter> newWindow = do_QueryInterface(*aResult);
+    NS_ASSERTION(newWindow == newDocShell->GetWindow(), "Different windows??");
+
+    // The principal of the initial about:blank document gets set up in
+    // nsWindowWatcher::AddWindow. Make sure to call it. In the common case
+    // this call already happened when the window was created, but
+    // SetInitialPrincipalToSubject is safe to call multiple times.
+    if (newWindow) {
+      newWindow->SetInitialPrincipalToSubject();
+      if (aIsPopupSpam) {
+        nsGlobalWindow* globalWin = nsGlobalWindow::Cast(newWindow);
+        MOZ_ASSERT(!globalWin->IsPopupSpamWindow(),
+                   "Who marked it as popup spam already???");
+        if (!globalWin->IsPopupSpamWindow()) { // Make sure we don't mess up our
+                                               // counter even if the above
+                                               // assert fails.
+          globalWin->SetIsPopupSpamWindow(true);
+        }
+      }
+    }
+  }
+
+  // We rely on CalculateChromeFlags to decide whether remote (out-of-process)
+  // tabs should be used.
+  bool isRemoteWindow =
+    !!(chromeFlags & nsIWebBrowserChrome::CHROME_REMOTE_WINDOW);
+
+  if (isNewToplevelWindow) {
+    nsCOMPtr<nsIDocShellTreeItem> childRoot;
+    newDocShellItem->GetRootTreeItem(getter_AddRefs(childRoot));
+    nsCOMPtr<nsILoadContext> childContext = do_QueryInterface(childRoot);
+    if (childContext) {
+      childContext->SetPrivateBrowsing(isPrivateBrowsingWindow);
+      childContext->SetRemoteTabs(isRemoteWindow);
+    }
+  } else if (windowIsNew) {
+    nsCOMPtr<nsILoadContext> childContext = do_QueryInterface(newDocShellItem);
+    if (childContext) {
+      childContext->SetPrivateBrowsing(isPrivateBrowsingWindow);
+      childContext->SetRemoteTabs(isRemoteWindow);
+    }
+  }
+
+  nsCOMPtr<nsIDocShellLoadInfo> loadInfo = aLoadInfo;
+  if (uriToLoad && aNavigate && !loadInfo) {
+    newDocShell->CreateLoadInfo(getter_AddRefs(loadInfo));
+    NS_ENSURE_TRUE(loadInfo, NS_ERROR_FAILURE);
+
+    if (subjectPrincipal) {
+      loadInfo->SetTriggeringPrincipal(subjectPrincipal);
+    }
+
+    /* use the URL from the *extant* document, if any. The usual accessor
+       GetDocument will synchronously create an about:blank document if
+       it has no better answer, and we only care about a real document.
+       Also using GetDocument to force document creation seems to
+       screw up focus in the hidden window; see bug 36016.
+    */
+    nsCOMPtr<nsIDocument> doc = GetEntryDocument();
+    if (!doc && parentWindow) {
+      doc = parentWindow->GetExtantDoc();
+    }
+    if (doc) {
+      // Set the referrer
+      loadInfo->SetReferrer(doc->GetDocumentURI());
+      loadInfo->SetReferrerPolicy(doc->GetReferrerPolicy());
+    }
+  }
+
+  if (isNewToplevelWindow) {
+    // Notify observers that the window is open and ready.
+    // The window has not yet started to load a document.
+    nsCOMPtr<nsIObserverService> obsSvc =
+      mozilla::services::GetObserverService();
+    if (obsSvc) {
+      obsSvc->NotifyObservers(*aResult, "toplevel-window-ready", nullptr);
+    }
+  }
+
+  // Before loading the URI we want to be 100% sure that we use the correct
+  // userContextId.
+  MOZ_ASSERT(CheckUserContextCompatibility(newDocShell));
+
+  if (uriToLoad && aNavigate) {
+    newDocShell->LoadURI(
+      uriToLoad,
+      loadInfo,
+      windowIsNew ?
+        static_cast<uint32_t>(nsIWebNavigation::LOAD_FLAGS_FIRST_LOAD) :
+        static_cast<uint32_t>(nsIWebNavigation::LOAD_FLAGS_NONE),
+      true);
+  }
+
+  // Copy the current session storage for the current domain.
+  if (subjectPrincipal && parentDocShell) {
+    nsCOMPtr<nsIDOMStorageManager> parentStorageManager =
+      do_QueryInterface(parentDocShell);
+    nsCOMPtr<nsIDOMStorageManager> newStorageManager =
+      do_QueryInterface(newDocShell);
+
+    if (parentStorageManager && newStorageManager) {
+      nsCOMPtr<nsIDOMStorage> storage;
+      nsCOMPtr<nsPIDOMWindowInner> pInnerWin = parentWindow->GetCurrentInnerWindow();
+
+      parentStorageManager->GetStorage(pInnerWin, subjectPrincipal,
+                                       isPrivateBrowsingWindow,
+                                       getter_AddRefs(storage));
+      if (storage) {
+        newStorageManager->CloneStorage(storage);
+      }
+    }
+  }
+
+  if (isNewToplevelWindow) {
+    nsCOMPtr<nsIDocShellTreeOwner> newTreeOwner;
+    newDocShellItem->GetTreeOwner(getter_AddRefs(newTreeOwner));
+    SizeOpenedWindow(newTreeOwner, aParent, isCallerChrome, sizeSpec);
+  }
+
+  // XXXbz isn't windowIsModal always true when windowIsModalContentDialog?
+  if (windowIsModal || windowIsModalContentDialog) {
+    nsCOMPtr<nsIDocShellTreeOwner> newTreeOwner;
+    newDocShellItem->GetTreeOwner(getter_AddRefs(newTreeOwner));
+    nsCOMPtr<nsIWebBrowserChrome> newChrome(do_GetInterface(newTreeOwner));
+
+    // Throw an exception here if no web browser chrome is available,
+    // we need that to show a modal window.
+    NS_ENSURE_TRUE(newChrome, NS_ERROR_NOT_AVAILABLE);
+
+    // Dispatch dialog events etc, but we only want to do that if
+    // we're opening a modal content window (the helper classes are
+    // no-ops if given no window), for chrome dialogs we don't want to
+    // do any of that (it's done elsewhere for us).
+    // Make sure we maintain the state on an outer window, because
+    // that's where it lives; inner windows assert if you try to
+    // maintain the state on them.
+    nsAutoWindowStateHelper windowStateHelper(
+      parentWindow ? parentWindow->GetOuterWindow() : nullptr);
+
+    if (!windowStateHelper.DefaultEnabled()) {
+      // Default to cancel not opening the modal window.
+      NS_RELEASE(*aResult);
+
+      return NS_OK;
+    }
+
+    bool isAppModal = false;
+    nsCOMPtr<nsIBaseWindow> parentWindow(do_GetInterface(newTreeOwner));
+    nsCOMPtr<nsIWidget> parentWidget;
+    if (parentWindow) {
+      parentWindow->GetMainWidget(getter_AddRefs(parentWidget));
+      if (parentWidget) {
+        isAppModal = parentWidget->IsRunningAppModal();
+      }
+    }
+    if (parentWidget &&
+        ((!newWindowShouldBeModal && parentIsModal) || isAppModal)) {
+      parentWidget->SetFakeModal(true);
+    } else {
+      // Reset popup state while opening a modal dialog, and firing
+      // events about the dialog, to prevent the current state from
+      // being active the whole time a modal dialog is open.
+      nsAutoPopupStatePusher popupStatePusher(openAbused);
+
+      newChrome->ShowAsModal();
+    }
+  }
+
+  if (aForceNoOpener && windowIsNew) {
+    NS_RELEASE(*aResult);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::RegisterNotification(nsIObserver* aObserver)
+{
+  // just a convenience method; it delegates to nsIObserverService
+
+  if (!aObserver) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
+  if (!os) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsresult rv = os->AddObserver(aObserver, "domwindowopened", false);
+  if (NS_SUCCEEDED(rv)) {
+    rv = os->AddObserver(aObserver, "domwindowclosed", false);
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::UnregisterNotification(nsIObserver* aObserver)
+{
+  // just a convenience method; it delegates to nsIObserverService
+
+  if (!aObserver) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
+  if (!os) {
+    return NS_ERROR_FAILURE;
+  }
+
+  os->RemoveObserver(aObserver, "domwindowopened");
+  os->RemoveObserver(aObserver, "domwindowclosed");
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::GetWindowEnumerator(nsISimpleEnumerator** aResult)
+{
+  if (!aResult) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  MutexAutoLock lock(mListLock);
+  nsWatcherWindowEnumerator* enumerator = new nsWatcherWindowEnumerator(this);
+  if (enumerator) {
+    return CallQueryInterface(enumerator, aResult);
+  }
+
+  return NS_ERROR_OUT_OF_MEMORY;
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::GetNewPrompter(mozIDOMWindowProxy* aParent, nsIPrompt** aResult)
+{
+  // This is for backwards compat only. Callers should just use the prompt
+  // service directly.
+  nsresult rv;
+  nsCOMPtr<nsIPromptFactory> factory =
+    do_GetService("@mozilla.org/prompter;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return factory->GetPrompt(aParent, NS_GET_IID(nsIPrompt),
+                            reinterpret_cast<void**>(aResult));
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::GetNewAuthPrompter(mozIDOMWindowProxy* aParent,
+                                    nsIAuthPrompt** aResult)
+{
+  // This is for backwards compat only. Callers should just use the prompt
+  // service directly.
+  nsresult rv;
+  nsCOMPtr<nsIPromptFactory> factory =
+    do_GetService("@mozilla.org/prompter;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return factory->GetPrompt(aParent, NS_GET_IID(nsIAuthPrompt),
+                            reinterpret_cast<void**>(aResult));
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::GetPrompt(mozIDOMWindowProxy* aParent, const nsIID& aIID,
+                           void** aResult)
+{
+  // This is for backwards compat only. Callers should just use the prompt
+  // service directly.
+  nsresult rv;
+  nsCOMPtr<nsIPromptFactory> factory =
+    do_GetService("@mozilla.org/prompter;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = factory->GetPrompt(aParent, aIID, aResult);
+
+  // Allow for an embedding implementation to not support nsIAuthPrompt2.
+  if (rv == NS_NOINTERFACE && aIID.Equals(NS_GET_IID(nsIAuthPrompt2))) {
+    nsCOMPtr<nsIAuthPrompt> oldPrompt;
+    rv = factory->GetPrompt(
+      aParent, NS_GET_IID(nsIAuthPrompt), getter_AddRefs(oldPrompt));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    NS_WrapAuthPrompt(oldPrompt, reinterpret_cast<nsIAuthPrompt2**>(aResult));
+    if (!*aResult) {
+      rv = NS_ERROR_NOT_AVAILABLE;
+    }
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::SetWindowCreator(nsIWindowCreator* aCreator)
+{
+  mWindowCreator = aCreator;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::HasWindowCreator(bool* aResult)
+{
+  *aResult = mWindowCreator;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::GetActiveWindow(mozIDOMWindowProxy** aActiveWindow)
+{
+  *aActiveWindow = nullptr;
+  nsCOMPtr<nsIFocusManager> fm = do_GetService(FOCUSMANAGER_CONTRACTID);
+  if (fm) {
+    return fm->GetActiveWindow(aActiveWindow);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::SetActiveWindow(mozIDOMWindowProxy* aActiveWindow)
+{
+  nsCOMPtr<nsIFocusManager> fm = do_GetService(FOCUSMANAGER_CONTRACTID);
+  if (fm) {
+    return fm->SetActiveWindow(aActiveWindow);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::AddWindow(mozIDOMWindowProxy* aWindow, nsIWebBrowserChrome* aChrome)
+{
+  if (!aWindow) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+#ifdef DEBUG
+  {
+    nsCOMPtr<nsPIDOMWindowOuter> win(do_QueryInterface(aWindow));
+
+    NS_ASSERTION(win->IsOuterWindow(),
+                 "Uh, the active window must be an outer window!");
+  }
+#endif
+
+  {
+    nsWatcherWindowEntry* info;
+    MutexAutoLock lock(mListLock);
+
+    // if we already have an entry for this window, adjust
+    // its chrome mapping and return
+    info = FindWindowEntry(aWindow);
+    if (info) {
+      nsCOMPtr<nsISupportsWeakReference> supportsweak(
+        do_QueryInterface(aChrome));
+      if (supportsweak) {
+        supportsweak->GetWeakReference(getter_AddRefs(info->mChromeWeak));
+      } else {
+        info->mChrome = aChrome;
+        info->mChromeWeak = nullptr;
+      }
+      return NS_OK;
+    }
+
+    // create a window info struct and add it to the list of windows
+    info = new nsWatcherWindowEntry(aWindow, aChrome);
+    if (!info) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    if (mOldestWindow) {
+      info->InsertAfter(mOldestWindow->mOlder);
+    } else {
+      mOldestWindow = info;
+    }
+  } // leave the mListLock
+
+  // a window being added to us signifies a newly opened window.
+  // send notifications.
+  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
+  if (!os) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsCOMPtr<nsISupports> domwin(do_QueryInterface(aWindow));
+  return os->NotifyObservers(domwin, "domwindowopened", 0);
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::RemoveWindow(mozIDOMWindowProxy* aWindow)
+{
+  // find the corresponding nsWatcherWindowEntry, remove it
+
+  if (!aWindow) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  nsWatcherWindowEntry* info = FindWindowEntry(aWindow);
+  if (info) {
+    RemoveWindow(info);
+    return NS_OK;
+  }
+  NS_WARNING("requested removal of nonexistent window");
+  return NS_ERROR_INVALID_ARG;
+}
+
+nsWatcherWindowEntry*
+nsWindowWatcher::FindWindowEntry(mozIDOMWindowProxy* aWindow)
+{
+  // find the corresponding nsWatcherWindowEntry
+  nsWatcherWindowEntry* info;
+  nsWatcherWindowEntry* listEnd;
+#ifdef USEWEAKREFS
+  nsresult rv;
+  bool found;
+#endif
+
+  info = mOldestWindow;
+  listEnd = 0;
+#ifdef USEWEAKREFS
+  rv = NS_OK;
+  found = false;
+  while (info != listEnd && NS_SUCCEEDED(rv)) {
+    nsCOMPtr<mozIDOMWindowProxy> infoWindow(do_QueryReferent(info->mWindow));
+    if (!infoWindow) { // clean up dangling reference, while we're here
+      rv = RemoveWindow(info);
+    } else if (infoWindow.get() == aWindow) {
+      return info;
+    }
+
+    info = info->mYounger;
+    listEnd = mOldestWindow;
+  }
+  return 0;
+#else
+  while (info != listEnd) {
+    if (info->mWindow == aWindow) {
+      return info;
+    }
+    info = info->mYounger;
+    listEnd = mOldestWindow;
+  }
+  return 0;
+#endif
+}
+
+nsresult
+nsWindowWatcher::RemoveWindow(nsWatcherWindowEntry* aInfo)
+{
+  uint32_t count = mEnumeratorList.Length();
+
+  {
+    // notify the enumerators
+    MutexAutoLock lock(mListLock);
+    for (uint32_t ctr = 0; ctr < count; ++ctr) {
+      mEnumeratorList[ctr]->WindowRemoved(aInfo);
+    }
+
+    // remove the element from the list
+    if (aInfo == mOldestWindow) {
+      mOldestWindow = aInfo->mYounger == mOldestWindow ? 0 : aInfo->mYounger;
+    }
+    aInfo->Unlink();
+  }
+
+  // a window being removed from us signifies a newly closed window.
+  // send notifications.
+  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
+  if (os) {
+#ifdef USEWEAKREFS
+    nsCOMPtr<nsISupports> domwin(do_QueryReferent(aInfo->mWindow));
+    if (domwin) {
+      os->NotifyObservers(domwin, "domwindowclosed", 0);
+    }
+    // else bummer. since the window is gone, there's nothing to notify with.
+#else
+    nsCOMPtr<nsISupports> domwin(do_QueryInterface(aInfo->mWindow));
+    os->NotifyObservers(domwin, "domwindowclosed", 0);
+#endif
+  }
+
+  delete aInfo;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::GetChromeForWindow(mozIDOMWindowProxy* aWindow,
+                                    nsIWebBrowserChrome** aResult)
+{
+  if (!aWindow || !aResult) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  *aResult = 0;
+
+  MutexAutoLock lock(mListLock);
+  nsWatcherWindowEntry* info = FindWindowEntry(aWindow);
+  if (info) {
+    if (info->mChromeWeak) {
+      return info->mChromeWeak->QueryReferent(
+        NS_GET_IID(nsIWebBrowserChrome), reinterpret_cast<void**>(aResult));
+    }
+    *aResult = info->mChrome;
+    NS_IF_ADDREF(*aResult);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWindowWatcher::GetWindowByName(const nsAString& aTargetName,
+                                 mozIDOMWindowProxy* aCurrentWindow,
+                                 mozIDOMWindowProxy** aResult)
+{
+  if (!aResult) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  *aResult = nullptr;
+
+  nsPIDOMWindowOuter* currentWindow =
+    aCurrentWindow ? nsPIDOMWindowOuter::From(aCurrentWindow) : nullptr;
+
+  nsCOMPtr<nsIDocShellTreeItem> treeItem;
+
+  nsCOMPtr<nsIDocShellTreeItem> startItem;
+  GetWindowTreeItem(currentWindow, getter_AddRefs(startItem));
+  if (startItem) {
+    // Note: original requestor is null here, per idl comments
+    startItem->FindItemWithName(aTargetName, nullptr, nullptr,
+                                getter_AddRefs(treeItem));
+  } else {
+    // Note: original requestor is null here, per idl comments
+    FindItemWithName(aTargetName, nullptr, nullptr, getter_AddRefs(treeItem));
+  }
+
+  if (treeItem) {
+    nsCOMPtr<nsPIDOMWindowOuter> domWindow = treeItem->GetWindow();
+    domWindow.forget(aResult);
+  }
+
+  return NS_OK;
+}
+
+bool
+nsWindowWatcher::AddEnumerator(nsWatcherWindowEnumerator* aEnumerator)
+{
+  // (requires a lock; assumes it's called by someone holding the lock)
+  return mEnumeratorList.AppendElement(aEnumerator) != nullptr;
+}
+
+bool
+nsWindowWatcher::RemoveEnumerator(nsWatcherWindowEnumerator* aEnumerator)
+{
+  // (requires a lock; assumes it's called by someone holding the lock)
+  return mEnumeratorList.RemoveElement(aEnumerator);
+}
+
+nsresult
+nsWindowWatcher::URIfromURL(const char* aURL,
+                            mozIDOMWindowProxy* aParent,
+                            nsIURI** aURI)
+{
+  // Build the URI relative to the entry global.
+  nsCOMPtr<nsPIDOMWindowInner> baseWindow = do_QueryInterface(GetEntryGlobal());
+
+  // failing that, build it relative to the parent window, if possible
+  if (!baseWindow && aParent) {
+    baseWindow = nsPIDOMWindowOuter::From(aParent)->GetCurrentInnerWindow();
+  }
+
+  // failing that, use the given URL unmodified. It had better not be relative.
+
+  nsIURI* baseURI = nullptr;
+
+  // get baseWindow's document URI
+  if (baseWindow) {
+    if (nsIDocument* doc = baseWindow->GetDoc()) {
+      baseURI = doc->GetDocBaseURI();
+    }
+  }
+
+  // build and return the absolute URI
+  return NS_NewURI(aURI, aURL, baseURI);
+}
+
+#define NS_CALCULATE_CHROME_FLAG_FOR(feature, flag)                       \
+  prefBranch->GetBoolPref(feature, &forceEnable);                     \
+  if (forceEnable && !aDialog && !aHasChromeParent && !aChromeURL) {  \
+    chromeFlags |= flag;                                              \
+  } else {                                                            \
+    chromeFlags |=                                                    \
+      WinHasOption(aFeatures, feature, 0, &presenceFlag) ? flag : 0;  \
+  }
+
+// static
+uint32_t
+nsWindowWatcher::CalculateChromeFlagsHelper(uint32_t aInitialFlags,
+                                            const nsACString& aFeatures,
+                                            bool& presenceFlag,
+                                            bool aDialog,
+                                            bool aHasChromeParent,
+                                            bool aChromeURL)
+{
+  uint32_t chromeFlags = aInitialFlags;
+
+  nsresult rv;
+  nsCOMPtr<nsIPrefBranch> prefBranch;
+  nsCOMPtr<nsIPrefService> prefs =
+    do_GetService(NS_PREFSERVICE_CONTRACTID, &rv);
+
+  NS_ENSURE_SUCCESS(rv, nsIWebBrowserChrome::CHROME_DEFAULT);
+
+  rv = prefs->GetBranch("dom.disable_window_open_feature.",
+                        getter_AddRefs(prefBranch));
+
+  NS_ENSURE_SUCCESS(rv, nsIWebBrowserChrome::CHROME_DEFAULT);
+
+  // NS_CALCULATE_CHROME_FLAG_FOR requires aFeatures, forceEnable, aDialog
+  // aHasChromeParent, aChromeURL, presenceFlag and chromeFlags to be in
+  // scope.
+  bool forceEnable = false;
+
+  NS_CALCULATE_CHROME_FLAG_FOR("titlebar",
+                               nsIWebBrowserChrome::CHROME_TITLEBAR);
+  NS_CALCULATE_CHROME_FLAG_FOR("close",
+                               nsIWebBrowserChrome::CHROME_WINDOW_CLOSE);
+  NS_CALCULATE_CHROME_FLAG_FOR("toolbar",
+                               nsIWebBrowserChrome::CHROME_TOOLBAR);
+  NS_CALCULATE_CHROME_FLAG_FOR("location",
+                               nsIWebBrowserChrome::CHROME_LOCATIONBAR);
+  NS_CALCULATE_CHROME_FLAG_FOR("personalbar",
+                               nsIWebBrowserChrome::CHROME_PERSONAL_TOOLBAR);
+  NS_CALCULATE_CHROME_FLAG_FOR("status",
+                               nsIWebBrowserChrome::CHROME_STATUSBAR);
+  NS_CALCULATE_CHROME_FLAG_FOR("menubar",
+                               nsIWebBrowserChrome::CHROME_MENUBAR);
+  NS_CALCULATE_CHROME_FLAG_FOR("resizable",
+                               nsIWebBrowserChrome::CHROME_WINDOW_RESIZE);
+  NS_CALCULATE_CHROME_FLAG_FOR("minimizable",
+                               nsIWebBrowserChrome::CHROME_WINDOW_MIN);
+
+  // default scrollbar to "on," unless explicitly turned off
+  if (WinHasOption(aFeatures, "scrollbars", 1, &presenceFlag) || !presenceFlag) {
+    chromeFlags |= nsIWebBrowserChrome::CHROME_SCROLLBARS;
+  }
+
+  return chromeFlags;
+}
+
+// static
+uint32_t
+nsWindowWatcher::EnsureFlagsSafeForContent(uint32_t aChromeFlags,
+                                           bool aChromeURL)
+{
+  aChromeFlags |= nsIWebBrowserChrome::CHROME_TITLEBAR;
+  aChromeFlags |= nsIWebBrowserChrome::CHROME_WINDOW_CLOSE;
+  aChromeFlags &= ~nsIWebBrowserChrome::CHROME_WINDOW_LOWERED;
+  aChromeFlags &= ~nsIWebBrowserChrome::CHROME_WINDOW_RAISED;
+  aChromeFlags &= ~nsIWebBrowserChrome::CHROME_WINDOW_POPUP;
+  /* Untrusted script is allowed to pose modal windows with a chrome
+     scheme. This check could stand to be better. But it effectively
+     prevents untrusted script from opening modal windows in general
+     while still allowing alerts and the like. */
+  if (!aChromeURL) {
+    aChromeFlags &= ~(nsIWebBrowserChrome::CHROME_MODAL |
+                     nsIWebBrowserChrome::CHROME_OPENAS_CHROME);
+  }
+
+  if (!(aChromeFlags & nsIWebBrowserChrome::CHROME_OPENAS_CHROME)) {
+    aChromeFlags &= ~nsIWebBrowserChrome::CHROME_DEPENDENT;
+  }
+
+  return aChromeFlags;
+}
+
+/**
+ * Calculate the chrome bitmask from a string list of features requested
+ * from a child process. Feature strings that are restricted to the parent
+ * process are ignored here.
+ * @param aFeatures a string containing a list of named features
+ * @return the chrome bitmask
+ */
+// static
+uint32_t
+nsWindowWatcher::CalculateChromeFlagsForChild(const nsACString& aFeatures)
+{
+  if (aFeatures.IsVoid()) {
+    return nsIWebBrowserChrome::CHROME_ALL;
+  }
+
+  bool presenceFlag = false;
+  uint32_t chromeFlags = CalculateChromeFlagsHelper(
+    nsIWebBrowserChrome::CHROME_WINDOW_BORDERS, aFeatures, presenceFlag);
+
+  return EnsureFlagsSafeForContent(chromeFlags);
+}
+
+/**
+ * Calculate the chrome bitmask from a string list of features for a new
+ * privileged window.
+ * @param aParent the opener window
+ * @param aFeatures a string containing a list of named chrome features
+ * @param aDialog affects the assumptions made about unnamed features
+ * @param aChromeURL true if the window is being sent to a chrome:// URL
+ * @param aHasChromeParent true if the parent window is privileged
+ * @param aCalledFromJS true if the window open request came from script.
+ * @return the chrome bitmask
+ */
+// static
+uint32_t
+nsWindowWatcher::CalculateChromeFlagsForParent(mozIDOMWindowProxy* aParent,
+                                               const nsACString& aFeatures,
+                                               bool aDialog,
+                                               bool aChromeURL,
+                                               bool aHasChromeParent,
+                                               bool aCalledFromJS)
+{
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(nsContentUtils::LegacyIsCallerChromeOrNativeCode());
+
+  uint32_t chromeFlags = 0;
+
+  // The features string is made void by OpenWindowInternal
+  // if nullptr was originally passed as the features string.
+  if (aFeatures.IsVoid()) {
+    chromeFlags = nsIWebBrowserChrome::CHROME_ALL;
+    if (aDialog) {
+      chromeFlags |= nsIWebBrowserChrome::CHROME_OPENAS_DIALOG |
+                     nsIWebBrowserChrome::CHROME_OPENAS_CHROME;
+    }
+  } else {
+    chromeFlags = nsIWebBrowserChrome::CHROME_WINDOW_BORDERS;
+  }
+
+  /* This function has become complicated since browser windows and
+     dialogs diverged. The difference is, browser windows assume all
+     chrome not explicitly mentioned is off, if the features string
+     is not null. Exceptions are some OS border chrome new with Mozilla.
+     Dialogs interpret a (mostly) empty features string to mean
+     "OS's choice," and also support an "all" flag explicitly disallowed
+     in the standards-compliant window.(normal)open. */
+
+  bool presenceFlag = false;
+  if (aDialog && WinHasOption(aFeatures, "all", 0, &presenceFlag)) {
+    chromeFlags = nsIWebBrowserChrome::CHROME_ALL;
+  }
+
+  /* Next, allow explicitly named options to override the initial settings */
+  chromeFlags = CalculateChromeFlagsHelper(chromeFlags, aFeatures, presenceFlag,
+                                           aDialog, aHasChromeParent, aChromeURL);
+
+  // Determine whether the window is a private browsing window
+  chromeFlags |= WinHasOption(aFeatures, "private", 0, &presenceFlag) ?
+    nsIWebBrowserChrome::CHROME_PRIVATE_WINDOW : 0;
+  chromeFlags |= WinHasOption(aFeatures, "non-private", 0, &presenceFlag) ?
+    nsIWebBrowserChrome::CHROME_NON_PRIVATE_WINDOW : 0;
+
+  // Determine whether the window should have remote tabs.
+  bool remote = BrowserTabsRemoteAutostart();
+
+  if (remote) {
+    remote = !WinHasOption(aFeatures, "non-remote", 0, &presenceFlag);
+  } else {
+    remote = WinHasOption(aFeatures, "remote", 0, &presenceFlag);
+  }
+
+  if (remote) {
+    chromeFlags |= nsIWebBrowserChrome::CHROME_REMOTE_WINDOW;
+  }
+
+  chromeFlags |= WinHasOption(aFeatures, "popup", 0, &presenceFlag) ?
+    nsIWebBrowserChrome::CHROME_WINDOW_POPUP : 0;
+
+  /* OK.
+     Normal browser windows, in spite of a stated pattern of turning off
+     all chrome not mentioned explicitly, will want the new OS chrome (window
+     borders, titlebars, closebox) on, unless explicitly turned off.
+     Dialogs, on the other hand, take the absence of any explicit settings
+     to mean "OS' choice." */
+
+  // default titlebar and closebox to "on," if not mentioned at all
+  if (!(chromeFlags & nsIWebBrowserChrome::CHROME_WINDOW_POPUP)) {
+    if (!PL_strcasestr(aFeatures.BeginReading(), "titlebar")) {
+      chromeFlags |= nsIWebBrowserChrome::CHROME_TITLEBAR;
+    }
+    if (!PL_strcasestr(aFeatures.BeginReading(), "close")) {
+      chromeFlags |= nsIWebBrowserChrome::CHROME_WINDOW_CLOSE;
+    }
+  }
+
+  if (aDialog && !aFeatures.IsVoid() && !presenceFlag) {
+    chromeFlags = nsIWebBrowserChrome::CHROME_DEFAULT;
+  }
+
+  /* Finally, once all the above normal chrome has been divined, deal
+     with the features that are more operating hints than appearance
+     instructions. (Note modality implies dependence.) */
+
+  if (WinHasOption(aFeatures, "alwaysLowered", 0, nullptr) ||
+      WinHasOption(aFeatures, "z-lock", 0, nullptr)) {
+    chromeFlags |= nsIWebBrowserChrome::CHROME_WINDOW_LOWERED;
+  } else if (WinHasOption(aFeatures, "alwaysRaised", 0, nullptr)) {
+    chromeFlags |= nsIWebBrowserChrome::CHROME_WINDOW_RAISED;
+  }
+
+  chromeFlags |= WinHasOption(aFeatures, "macsuppressanimation", 0, nullptr) ?
+    nsIWebBrowserChrome::CHROME_MAC_SUPPRESS_ANIMATION : 0;
+
+  chromeFlags |= WinHasOption(aFeatures, "chrome", 0, nullptr) ?
+    nsIWebBrowserChrome::CHROME_OPENAS_CHROME : 0;
+  chromeFlags |= WinHasOption(aFeatures, "extrachrome", 0, nullptr) ?
+    nsIWebBrowserChrome::CHROME_EXTRA : 0;
+  chromeFlags |= WinHasOption(aFeatures, "centerscreen", 0, nullptr) ?
+    nsIWebBrowserChrome::CHROME_CENTER_SCREEN : 0;
+  chromeFlags |= WinHasOption(aFeatures, "dependent", 0, nullptr) ?
+    nsIWebBrowserChrome::CHROME_DEPENDENT : 0;
+  chromeFlags |= WinHasOption(aFeatures, "modal", 0, nullptr) ?
+    (nsIWebBrowserChrome::CHROME_MODAL | nsIWebBrowserChrome::CHROME_DEPENDENT) : 0;
+
+  /* On mobile we want to ignore the dialog window feature, since the mobile UI
+     does not provide any affordance for dialog windows. This does not interfere
+     with dialog windows created through openDialog. */
+  bool disableDialogFeature = false;
+  nsCOMPtr<nsIPrefBranch> branch = do_GetService(NS_PREFSERVICE_CONTRACTID);
+
+  branch->GetBoolPref("dom.disable_window_open_dialog_feature",
+                      &disableDialogFeature);
+
+  if (!disableDialogFeature) {
+    chromeFlags |= WinHasOption(aFeatures, "dialog", 0, nullptr) ?
+      nsIWebBrowserChrome::CHROME_OPENAS_DIALOG : 0;
+  }
+
+  /* and dialogs need to have the last word. assume dialogs are dialogs,
+     and opened as chrome, unless explicitly told otherwise. */
+  if (aDialog) {
+    if (!PL_strcasestr(aFeatures.BeginReading(), "dialog")) {
+      chromeFlags |= nsIWebBrowserChrome::CHROME_OPENAS_DIALOG;
+    }
+    if (!PL_strcasestr(aFeatures.BeginReading(), "chrome")) {
+      chromeFlags |= nsIWebBrowserChrome::CHROME_OPENAS_CHROME;
+    }
+  }
+
+  /* missing
+     chromeFlags->copy_history
+   */
+
+  // Check security state for use in determing window dimensions
+  if (!aHasChromeParent) {
+    chromeFlags = EnsureFlagsSafeForContent(chromeFlags, aChromeURL);
+  }
+
+  // Disable CHROME_OPENAS_DIALOG if the window is inside <iframe mozbrowser>.
+  // It's up to the embedder to interpret what dialog=1 means.
+  nsCOMPtr<nsIDocShell> docshell = do_GetInterface(aParent);
+  if (docshell && docshell->GetIsInMozBrowserOrApp()) {
+    chromeFlags &= ~nsIWebBrowserChrome::CHROME_OPENAS_DIALOG;
+  }
+
+  return chromeFlags;
+}
+
+// static
+int32_t
+nsWindowWatcher::WinHasOption(const nsACString& aOptions, const char* aName,
+                              int32_t aDefault, bool* aPresenceFlag)
+{
+  if (aOptions.IsEmpty()) {
+    return 0;
+  }
+
+  const char* options = aOptions.BeginReading();
+  char* comma;
+  char* equal;
+  int32_t found = 0;
+
+#ifdef DEBUG
+  NS_ASSERTION(nsAutoCString(aOptions).FindCharInSet(" \n\r\t") == kNotFound,
+               "There should be no whitespace in this string!");
+#endif
+
+  while (true) {
+    comma = PL_strchr(options, ',');
+    if (comma) {
+      *comma = '\0';
+    }
+    equal = PL_strchr(options, '=');
+    if (equal) {
+      *equal = '\0';
+    }
+    if (nsCRT::strcasecmp(options, aName) == 0) {
+      if (aPresenceFlag) {
+        *aPresenceFlag = true;
+      }
+      if (equal)
+        if (*(equal + 1) == '*') {
+          found = aDefault;
+        } else if (nsCRT::strcasecmp(equal + 1, "yes") == 0) {
+          found = 1;
+        } else {
+          found = atoi(equal + 1);
+        }
+      else {
+        found = 1;
+      }
+    }
+    if (equal) {
+      *equal = '=';
+    }
+    if (comma) {
+      *comma = ',';
+    }
+    if (found || !comma) {
+      break;
+    }
+    options = comma + 1;
+  }
+  return found;
+}
+
+/* try to find an nsIDocShellTreeItem with the given name in any
+   known open window. a failure to find the item will not
+   necessarily return a failure method value. check aFoundItem.
+*/
+NS_IMETHODIMP
+nsWindowWatcher::FindItemWithName(const nsAString& aName,
+                                  nsIDocShellTreeItem* aRequestor,
+                                  nsIDocShellTreeItem* aOriginalRequestor,
+                                  nsIDocShellTreeItem** aFoundItem)
+{
+  *aFoundItem = nullptr;
+  if (aName.IsEmpty()) {
+    return NS_OK;
+  }
+
+  if (aName.LowerCaseEqualsLiteral("_blank") ||
+      aName.LowerCaseEqualsLiteral("_top") ||
+      aName.LowerCaseEqualsLiteral("_parent") ||
+      aName.LowerCaseEqualsLiteral("_self")) {
+    return NS_OK;
+  }
+
+  // If we are looking for an item and we don't have a docshell we are checking
+  // on, let's just look in the chrome tab group!
+  return TabGroup::GetChromeTabGroup()->FindItemWithName(aName,
+                                                         aRequestor,
+                                                         aOriginalRequestor,
+                                                         aFoundItem);
+}
+
+already_AddRefed<nsIDocShellTreeItem>
+nsWindowWatcher::GetCallerTreeItem(nsIDocShellTreeItem* aParentItem)
+{
+  nsCOMPtr<nsIWebNavigation> callerWebNav = do_GetInterface(GetEntryGlobal());
+  nsCOMPtr<nsIDocShellTreeItem> callerItem = do_QueryInterface(callerWebNav);
+  if (!callerItem) {
+    callerItem = aParentItem;
+  }
+
+  return callerItem.forget();
+}
+
+nsPIDOMWindowOuter*
+nsWindowWatcher::SafeGetWindowByName(const nsAString& aName,
+                                     bool aForceNoOpener,
+                                     mozIDOMWindowProxy* aCurrentWindow)
+{
+  if (aForceNoOpener) {
+    if (!aName.LowerCaseEqualsLiteral("_self") &&
+        !aName.LowerCaseEqualsLiteral("_top") &&
+        !aName.LowerCaseEqualsLiteral("_parent")) {
+      // Ignore all other names in the noopener case.
+      return nullptr;
+    }
+  }
+
+  nsCOMPtr<nsIDocShellTreeItem> startItem;
+  GetWindowTreeItem(aCurrentWindow, getter_AddRefs(startItem));
+
+  nsCOMPtr<nsIDocShellTreeItem> callerItem = GetCallerTreeItem(startItem);
+
+  nsCOMPtr<nsIDocShellTreeItem> foundItem;
+  if (startItem) {
+    startItem->FindItemWithName(aName, nullptr, callerItem,
+                                getter_AddRefs(foundItem));
+  } else {
+    FindItemWithName(aName, nullptr, callerItem,
+                     getter_AddRefs(foundItem));
+  }
+
+  return foundItem ? foundItem->GetWindow() : nullptr;
+}
+
+/* Fetch the nsIDOMWindow corresponding to the given nsIDocShellTreeItem.
+   This forces the creation of a script context, if one has not already
+   been created. Note it also sets the window's opener to the parent,
+   if applicable -- because it's just convenient, that's all. null aParent
+   is acceptable. */
+nsresult
+nsWindowWatcher::ReadyOpenedDocShellItem(nsIDocShellTreeItem* aOpenedItem,
+                                         nsPIDOMWindowOuter* aParent,
+                                         bool aWindowIsNew,
+                                         bool aForceNoOpener,
+                                         mozIDOMWindowProxy** aOpenedWindow)
+{
+  nsresult rv = NS_ERROR_FAILURE;
+
+  NS_ENSURE_ARG(aOpenedWindow);
+
+  *aOpenedWindow = 0;
+  nsCOMPtr<nsPIDOMWindowOuter> piOpenedWindow = aOpenedItem->GetWindow();
+  if (piOpenedWindow) {
+    if (!aForceNoOpener) {
+      piOpenedWindow->SetOpenerWindow(aParent, aWindowIsNew); // damnit
+    } else if (aParent && aParent != piOpenedWindow) {
+      MOZ_ASSERT(piOpenedWindow->TabGroup() != aParent->TabGroup(),
+                 "If we're forcing no opener, they should be in different tab groups");
+    }
+
+    if (aWindowIsNew) {
+#ifdef DEBUG
+      // Assert that we're not loading things right now.  If we are, when
+      // that load completes it will clobber whatever principals we set up
+      // on this new window!
+      nsCOMPtr<nsIDocumentLoader> docloader = do_QueryInterface(aOpenedItem);
+      NS_ASSERTION(docloader, "How can we not have a docloader here?");
+
+      nsCOMPtr<nsIChannel> chan;
+      docloader->GetDocumentChannel(getter_AddRefs(chan));
+      NS_ASSERTION(!chan, "Why is there a document channel?");
+#endif
+
+      nsCOMPtr<nsIDocument> doc = piOpenedWindow->GetExtantDoc();
+      if (doc) {
+        doc->SetIsInitialDocument(true);
+      }
+    }
+    rv = CallQueryInterface(piOpenedWindow, aOpenedWindow);
+  }
+  return rv;
+}
+
+// static
+void
+nsWindowWatcher::CalcSizeSpec(const nsACString& aFeatures, SizeSpec& aResult)
+{
+  // Parse position spec, if any, from aFeatures
+  bool present;
+  int32_t temp;
+
+  present = false;
+  if ((temp = WinHasOption(aFeatures, "left", 0, &present)) || present) {
+    aResult.mLeft = temp;
+  } else if ((temp = WinHasOption(aFeatures, "screenX", 0, &present)) ||
+             present) {
+    aResult.mLeft = temp;
+  }
+  aResult.mLeftSpecified = present;
+
+  present = false;
+  if ((temp = WinHasOption(aFeatures, "top", 0, &present)) || present) {
+    aResult.mTop = temp;
+  } else if ((temp = WinHasOption(aFeatures, "screenY", 0, &present)) ||
+             present) {
+    aResult.mTop = temp;
+  }
+  aResult.mTopSpecified = present;
+
+  // Parse size spec, if any. Chrome size overrides content size.
+  if ((temp = WinHasOption(aFeatures, "outerWidth", INT32_MIN, nullptr))) {
+    if (temp == INT32_MIN) {
+      aResult.mUseDefaultWidth = true;
+    } else {
+      aResult.mOuterWidth = temp;
+    }
+    aResult.mOuterWidthSpecified = true;
+  } else if ((temp = WinHasOption(aFeatures, "width", INT32_MIN, nullptr)) ||
+             (temp = WinHasOption(aFeatures, "innerWidth", INT32_MIN,
+                                  nullptr))) {
+    if (temp == INT32_MIN) {
+      aResult.mUseDefaultWidth = true;
+    } else {
+      aResult.mInnerWidth = temp;
+    }
+    aResult.mInnerWidthSpecified = true;
+  }
+
+  if ((temp = WinHasOption(aFeatures, "outerHeight", INT32_MIN, nullptr))) {
+    if (temp == INT32_MIN) {
+      aResult.mUseDefaultHeight = true;
+    } else {
+      aResult.mOuterHeight = temp;
+    }
+    aResult.mOuterHeightSpecified = true;
+  } else if ((temp = WinHasOption(aFeatures, "height", INT32_MIN,
+                                  nullptr)) ||
+             (temp = WinHasOption(aFeatures, "innerHeight", INT32_MIN,
+                                  nullptr))) {
+    if (temp == INT32_MIN) {
+      aResult.mUseDefaultHeight = true;
+    } else {
+      aResult.mInnerHeight = temp;
+    }
+    aResult.mInnerHeightSpecified = true;
+  }
+}
+
+/* Size and position a new window according to aSizeSpec. This method
+   is assumed to be called after the window has already been given
+   a default position and size; thus its current position and size are
+   accurate defaults. The new window is made visible at method end.
+   @param aTreeOwner
+          The top-level nsIDocShellTreeOwner of the newly opened window.
+   @param aParent (optional)
+          The parent window from which to inherit zoom factors from if
+          aOpenerFullZoom is none.
+   @param aIsCallerChrome
+          True if the code requesting the new window is privileged.
+   @param aSizeSpec
+          The size that the new window should be.
+   @param aOpenerFullZoom
+          If not nothing, a zoom factor to scale the content to.
+*/
+void
+nsWindowWatcher::SizeOpenedWindow(nsIDocShellTreeOwner* aTreeOwner,
+                                  mozIDOMWindowProxy* aParent,
+                                  bool aIsCallerChrome,
+                                  const SizeSpec& aSizeSpec,
+                                  Maybe<float> aOpenerFullZoom)
+{
+  // We should only be sizing top-level windows if we're in the parent
+  // process.
+  MOZ_ASSERT(XRE_IsParentProcess());
+
+  // position and size of window
+  int32_t left = 0, top = 0, width = 100, height = 100;
+  // difference between chrome and content size
+  int32_t chromeWidth = 0, chromeHeight = 0;
+  // whether the window size spec refers to chrome or content
+  bool sizeChromeWidth = true, sizeChromeHeight = true;
+
+  // get various interfaces for aDocShellItem, used throughout this method
+  nsCOMPtr<nsIBaseWindow> treeOwnerAsWin(do_QueryInterface(aTreeOwner));
+  if (!treeOwnerAsWin) { // we'll need this to actually size the docshell
+    return;
+  }
+
+  double openerZoom = aOpenerFullZoom.valueOr(1.0);
+  if (aParent && aOpenerFullZoom.isNothing()) {
+    nsCOMPtr<nsPIDOMWindowOuter> piWindow = nsPIDOMWindowOuter::From(aParent);
+    if (nsIDocument* doc = piWindow->GetDoc()) {
+      if (nsIPresShell* shell = doc->GetShell()) {
+        if (nsPresContext* presContext = shell->GetPresContext()) {
+          openerZoom = presContext->GetFullZoom();
+        }
+      }
+    }
+  }
+
+  double scale = 1.0;
+  treeOwnerAsWin->GetUnscaledDevicePixelsPerCSSPixel(&scale);
+
+  /* The current position and size will be unchanged if not specified
+     (and they fit entirely onscreen). Also, calculate the difference
+     between chrome and content sizes on aDocShellItem's window.
+     This latter point becomes important if chrome and content
+     specifications are mixed in aFeatures, and when bringing the window
+     back from too far off the right or bottom edges of the screen. */
+
+  treeOwnerAsWin->GetPositionAndSize(&left, &top, &width, &height);
+  left = NSToIntRound(left / scale);
+  top = NSToIntRound(top / scale);
+  width = NSToIntRound(width / scale);
+  height = NSToIntRound(height / scale);
+  {
+    int32_t contentWidth, contentHeight;
+    bool hasPrimaryContent = false;
+    aTreeOwner->GetHasPrimaryContent(&hasPrimaryContent);
+    if (hasPrimaryContent) {
+      aTreeOwner->GetPrimaryContentSize(&contentWidth, &contentHeight);
+    } else {
+      aTreeOwner->GetRootShellSize(&contentWidth, &contentHeight);
+    }
+    chromeWidth = width - contentWidth;
+    chromeHeight = height - contentHeight;
+  }
+
+  // Set up left/top
+  if (aSizeSpec.mLeftSpecified) {
+    left = NSToIntRound(aSizeSpec.mLeft * openerZoom);
+  }
+
+  if (aSizeSpec.mTopSpecified) {
+    top = NSToIntRound(aSizeSpec.mTop * openerZoom);
+  }
+
+  // Set up width
+  if (aSizeSpec.mOuterWidthSpecified) {
+    if (!aSizeSpec.mUseDefaultWidth) {
+      width = NSToIntRound(aSizeSpec.mOuterWidth * openerZoom);
+    } // Else specified to default; just use our existing width
+  } else if (aSizeSpec.mInnerWidthSpecified) {
+    sizeChromeWidth = false;
+    if (aSizeSpec.mUseDefaultWidth) {
+      width = width - chromeWidth;
+    } else {
+      width = NSToIntRound(aSizeSpec.mInnerWidth * openerZoom);
+    }
+  }
+
+  // Set up height
+  if (aSizeSpec.mOuterHeightSpecified) {
+    if (!aSizeSpec.mUseDefaultHeight) {
+      height = NSToIntRound(aSizeSpec.mOuterHeight * openerZoom);
+    } // Else specified to default; just use our existing height
+  } else if (aSizeSpec.mInnerHeightSpecified) {
+    sizeChromeHeight = false;
+    if (aSizeSpec.mUseDefaultHeight) {
+      height = height - chromeHeight;
+    } else {
+      height = NSToIntRound(aSizeSpec.mInnerHeight * openerZoom);
+    }
+  }
+
+  bool positionSpecified = aSizeSpec.PositionSpecified();
+
+  // Check security state for use in determing window dimensions
+  bool enabled = false;
+  if (aIsCallerChrome) {
+    // Only enable special priveleges for chrome when chrome calls
+    // open() on a chrome window
+    nsCOMPtr<nsIDOMChromeWindow> chromeWin(do_QueryInterface(aParent));
+    enabled = !aParent || chromeWin;
+  }
+
+  if (!enabled) {
+    // Security check failed.  Ensure all args meet minimum reqs.
+
+    int32_t oldTop = top, oldLeft = left;
+
+    // We'll also need the screen dimensions
+    nsCOMPtr<nsIScreen> screen;
+    nsCOMPtr<nsIScreenManager> screenMgr(
+      do_GetService("@mozilla.org/gfx/screenmanager;1"));
+    if (screenMgr)
+      screenMgr->ScreenForRect(left, top, width, height,
+                               getter_AddRefs(screen));
+    if (screen) {
+      int32_t screenLeft, screenTop, screenWidth, screenHeight;
+      int32_t winWidth = width + (sizeChromeWidth ? 0 : chromeWidth),
+              winHeight = height + (sizeChromeHeight ? 0 : chromeHeight);
+
+      // Get screen dimensions (in device pixels)
+      screen->GetAvailRect(&screenLeft, &screenTop, &screenWidth,
+                           &screenHeight);
+      // Convert them to CSS pixels
+      screenLeft = NSToIntRound(screenLeft / scale);
+      screenTop = NSToIntRound(screenTop / scale);
+      screenWidth = NSToIntRound(screenWidth / scale);
+      screenHeight = NSToIntRound(screenHeight / scale);
+
+      if (aSizeSpec.SizeSpecified()) {
+        /* Unlike position, force size out-of-bounds check only if
+           size actually was specified. Otherwise, intrinsically sized
+           windows are broken. */
+        if (height < 100) {
+          height = 100;
+          winHeight = height + (sizeChromeHeight ? 0 : chromeHeight);
+        }
+        if (winHeight > screenHeight) {
+          height = screenHeight - (sizeChromeHeight ? 0 : chromeHeight);
+        }
+        if (width < 100) {
+          width = 100;
+          winWidth = width + (sizeChromeWidth ? 0 : chromeWidth);
+        }
+        if (winWidth > screenWidth) {
+          width = screenWidth - (sizeChromeWidth ? 0 : chromeWidth);
+        }
+      }
+
+      if (left + winWidth > screenLeft + screenWidth ||
+          left + winWidth < left) {
+        left = screenLeft + screenWidth - winWidth;
+      }
+      if (left < screenLeft) {
+        left = screenLeft;
+      }
+      if (top + winHeight > screenTop + screenHeight || top + winHeight < top) {
+        top = screenTop + screenHeight - winHeight;
+      }
+      if (top < screenTop) {
+        top = screenTop;
+      }
+      if (top != oldTop || left != oldLeft) {
+        positionSpecified = true;
+      }
+    }
+  }
+
+  // size and position the window
+
+  if (positionSpecified) {
+    // Get the scale factor appropriate for the screen we're actually
+    // positioning on.
+    nsCOMPtr<nsIScreen> screen;
+    nsCOMPtr<nsIScreenManager> screenMgr(
+      do_GetService("@mozilla.org/gfx/screenmanager;1"));
+    if (screenMgr) {
+      screenMgr->ScreenForRect(left, top, 1, 1, getter_AddRefs(screen));
+    }
+    if (screen) {
+      double cssToDevPixScale, desktopToDevPixScale;
+      screen->GetDefaultCSSScaleFactor(&cssToDevPixScale);
+      screen->GetContentsScaleFactor(&desktopToDevPixScale);
+      double cssToDesktopScale = cssToDevPixScale / desktopToDevPixScale;
+      int32_t screenLeft, screenTop, screenWd, screenHt;
+      screen->GetRectDisplayPix(&screenLeft, &screenTop, &screenWd, &screenHt);
+      // Adjust by desktop-pixel origin of the target screen when scaling
+      // to convert from per-screen CSS-px coords to global desktop coords.
+      treeOwnerAsWin->SetPositionDesktopPix(
+        (left - screenLeft) * cssToDesktopScale + screenLeft,
+        (top - screenTop) * cssToDesktopScale + screenTop);
+    } else {
+      // Couldn't find screen? This shouldn't happen.
+      treeOwnerAsWin->SetPosition(left * scale, top * scale);
+    }
+    // This shouldn't be necessary, given the screen check above, but in case
+    // moving the window didn't put it where we expected (e.g. due to issues
+    // at the widget level, or whatever), let's re-fetch the scale factor for
+    // wherever it really ended up
+    treeOwnerAsWin->GetUnscaledDevicePixelsPerCSSPixel(&scale);
+  }
+  if (aSizeSpec.SizeSpecified()) {
+    /* Prefer to trust the interfaces, which think in terms of pure
+       chrome or content sizes. If we have a mix, use the chrome size
+       adjusted by the chrome/content differences calculated earlier. */
+    if (!sizeChromeWidth && !sizeChromeHeight) {
+      bool hasPrimaryContent = false;
+      aTreeOwner->GetHasPrimaryContent(&hasPrimaryContent);
+      if (hasPrimaryContent) {
+        aTreeOwner->SetPrimaryContentSize(width * scale, height * scale);
+      } else {
+        aTreeOwner->SetRootShellSize(width * scale, height * scale);
+      }
+    } else {
+      if (!sizeChromeWidth) {
+        width += chromeWidth;
+      }
+      if (!sizeChromeHeight) {
+        height += chromeHeight;
+      }
+      treeOwnerAsWin->SetSize(width * scale, height * scale, false);
+    }
+  }
+  treeOwnerAsWin->SetVisibility(true);
+}
+
+void
+nsWindowWatcher::GetWindowTreeItem(mozIDOMWindowProxy* aWindow,
+                                   nsIDocShellTreeItem** aResult)
+{
+  *aResult = 0;
+
+  if (aWindow) {
+    nsIDocShell* docshell = nsPIDOMWindowOuter::From(aWindow)->GetDocShell();
+    if (docshell) {
+      CallQueryInterface(docshell, aResult);
+    }
+  }
+}
+
+void
+nsWindowWatcher::GetWindowTreeOwner(nsPIDOMWindowOuter* aWindow,
+                                    nsIDocShellTreeOwner** aResult)
+{
+  *aResult = 0;
+
+  nsCOMPtr<nsIDocShellTreeItem> treeItem;
+  GetWindowTreeItem(aWindow, getter_AddRefs(treeItem));
+  if (treeItem) {
+    treeItem->GetTreeOwner(aResult);
+  }
+}
+
+/* static */
+int32_t
+nsWindowWatcher::GetWindowOpenLocation(nsPIDOMWindowOuter* aParent,
+                                       uint32_t aChromeFlags,
+                                       bool aCalledFromJS,
+                                       bool aPositionSpecified,
+                                       bool aSizeSpecified)
+{
+  bool isFullScreen = aParent->GetFullScreen();
+
+  // Where should we open this?
+  int32_t containerPref;
+  if (NS_FAILED(Preferences::GetInt("browser.link.open_newwindow",
+                                    &containerPref))) {
+    // We couldn't read the user preference, so fall back on the default.
+    return nsIBrowserDOMWindow::OPEN_NEWTAB;
+  }
+
+  bool isDisabledOpenNewWindow =
+    isFullScreen &&
+    Preferences::GetBool("browser.link.open_newwindow.disabled_in_fullscreen");
+
+  if (isDisabledOpenNewWindow &&
+      (containerPref == nsIBrowserDOMWindow::OPEN_NEWWINDOW)) {
+    containerPref = nsIBrowserDOMWindow::OPEN_NEWTAB;
+  }
+
+  if (containerPref != nsIBrowserDOMWindow::OPEN_NEWTAB &&
+      containerPref != nsIBrowserDOMWindow::OPEN_CURRENTWINDOW) {
+    // Just open a window normally
+    return nsIBrowserDOMWindow::OPEN_NEWWINDOW;
+  }
+
+  if (aCalledFromJS) {
+    /* Now check our restriction pref.  The restriction pref is a power-user's
+       fine-tuning pref. values:
+       0: no restrictions - divert everything
+       1: don't divert window.open at all
+       2: don't divert window.open with features
+    */
+    int32_t restrictionPref =
+      Preferences::GetInt("browser.link.open_newwindow.restriction", 2);
+    if (restrictionPref < 0 || restrictionPref > 2) {
+      restrictionPref = 2; // Sane default behavior
+    }
+
+    if (isDisabledOpenNewWindow) {
+      // In browser fullscreen, the window should be opened
+      // in the current window with no features (see bug 803675)
+      restrictionPref = 0;
+    }
+
+    if (restrictionPref == 1) {
+      return nsIBrowserDOMWindow::OPEN_NEWWINDOW;
+    }
+
+    if (restrictionPref == 2) {
+      // Only continue if there are no size/position features and no special
+      // chrome flags - with the exception of the remoteness and private flags,
+      // which might have been automatically flipped by Gecko.
+      int32_t uiChromeFlags = aChromeFlags;
+      uiChromeFlags &= ~(nsIWebBrowserChrome::CHROME_REMOTE_WINDOW |
+                         nsIWebBrowserChrome::CHROME_PRIVATE_WINDOW |
+                         nsIWebBrowserChrome::CHROME_NON_PRIVATE_WINDOW |
+                         nsIWebBrowserChrome::CHROME_PRIVATE_LIFETIME);
+      if (uiChromeFlags != nsIWebBrowserChrome::CHROME_ALL ||
+          aPositionSpecified || aSizeSpecified) {
+        return nsIBrowserDOMWindow::OPEN_NEWWINDOW;
+      }
+    }
+  }
+
+  return containerPref;
+}
diff --git a/embedding/components/windowwatcher/nsWindowWatcher.h b/embedding/components/windowwatcher/nsWindowWatcher.h
new file mode 100644
index 000000000..f2728bc16
--- /dev/null
+++ b/embedding/components/windowwatcher/nsWindowWatcher.h
@@ -0,0 +1,156 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef __nsWindowWatcher_h__
+#define __nsWindowWatcher_h__
+
+// {a21bfa01-f349-4394-a84c-8de5cf0737d0}
+#define NS_WINDOWWATCHER_CID \
+  {0xa21bfa01, 0xf349, 0x4394, {0xa8, 0x4c, 0x8d, 0xe5, 0xcf, 0x7, 0x37, 0xd0}}
+
+#include "nsCOMPtr.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/Maybe.h"
+#include "nsIWindowCreator.h" // for stupid compilers
+#include "nsIWindowWatcher.h"
+#include "nsIPromptFactory.h"
+#include "nsITabParent.h"
+#include "nsPIWindowWatcher.h"
+#include "nsTArray.h"
+
+class nsIURI;
+class nsIDocShellTreeItem;
+class nsIDocShellTreeOwner;
+class nsPIDOMWindowOuter;
+class nsWatcherWindowEnumerator;
+class nsPromptService;
+struct nsWatcherWindowEntry;
+struct SizeSpec;
+
+class nsWindowWatcher
+  : public nsIWindowWatcher
+  , public nsPIWindowWatcher
+  , public nsIPromptFactory
+{
+  friend class nsWatcherWindowEnumerator;
+
+public:
+  nsWindowWatcher();
+
+  nsresult Init();
+
+  NS_DECL_ISUPPORTS
+
+  NS_DECL_NSIWINDOWWATCHER
+  NS_DECL_NSPIWINDOWWATCHER
+  NS_DECL_NSIPROMPTFACTORY
+
+  static int32_t GetWindowOpenLocation(nsPIDOMWindowOuter* aParent,
+                                       uint32_t aChromeFlags,
+                                       bool aCalledFromJS,
+                                       bool aPositionSpecified,
+                                       bool aSizeSpecified);
+
+protected:
+  virtual ~nsWindowWatcher();
+
+  friend class nsPromptService;
+  bool AddEnumerator(nsWatcherWindowEnumerator* aEnumerator);
+  bool RemoveEnumerator(nsWatcherWindowEnumerator* aEnumerator);
+
+  nsWatcherWindowEntry* FindWindowEntry(mozIDOMWindowProxy* aWindow);
+  nsresult RemoveWindow(nsWatcherWindowEntry* aInfo);
+
+  // Get the caller tree item.  Look on the JS stack, then fall back
+  // to the parent if there's nothing there.
+  already_AddRefed<nsIDocShellTreeItem> GetCallerTreeItem(
+    nsIDocShellTreeItem* aParentItem);
+
+  // Unlike GetWindowByName this will look for a caller on the JS
+  // stack, and then fall back on aCurrentWindow if it can't find one.
+  // It also knows to not look for things if aForceNoOpener is set.
+  nsPIDOMWindowOuter* SafeGetWindowByName(const nsAString& aName,
+                                          bool aForceNoOpener,
+                                          mozIDOMWindowProxy* aCurrentWindow);
+
+  // Just like OpenWindowJS, but knows whether it got called via OpenWindowJS
+  // (which means called from script) or called via OpenWindow.
+  nsresult OpenWindowInternal(mozIDOMWindowProxy* aParent,
+                              const char* aUrl,
+                              const char* aName,
+                              const char* aFeatures,
+                              bool aCalledFromJS,
+                              bool aDialog,
+                              bool aNavigate,
+                              nsIArray* aArgv,
+                              bool aIsPopupSpam,
+                              bool aForceNoOpener,
+                              nsIDocShellLoadInfo* aLoadInfo,
+                              mozIDOMWindowProxy** aResult);
+
+  static nsresult URIfromURL(const char* aURL,
+                             mozIDOMWindowProxy* aParent,
+                             nsIURI** aURI);
+
+  static uint32_t CalculateChromeFlagsForChild(const nsACString& aFeaturesStr);
+
+  static uint32_t CalculateChromeFlagsForParent(mozIDOMWindowProxy* aParent,
+                                                const nsACString& aFeaturesStr,
+                                                bool aDialog,
+                                                bool aChromeURL,
+                                                bool aHasChromeParent,
+                                                bool aCalledFromJS);
+
+  static int32_t WinHasOption(const nsACString& aOptions, const char* aName,
+                              int32_t aDefault, bool* aPresenceFlag);
+  /* Compute the right SizeSpec based on aFeatures */
+  static void CalcSizeSpec(const nsACString& aFeatures, SizeSpec& aResult);
+  static nsresult ReadyOpenedDocShellItem(nsIDocShellTreeItem* aOpenedItem,
+                                          nsPIDOMWindowOuter* aParent,
+                                          bool aWindowIsNew,
+                                          bool aForceNoOpener,
+                                          mozIDOMWindowProxy** aOpenedWindow);
+  static void SizeOpenedWindow(nsIDocShellTreeOwner* aTreeOwner,
+                               mozIDOMWindowProxy* aParent,
+                               bool aIsCallerChrome,
+                               const SizeSpec& aSizeSpec,
+                               mozilla::Maybe<float> aOpenerFullZoom =
+                                 mozilla::Nothing());
+  static void GetWindowTreeItem(mozIDOMWindowProxy* aWindow,
+                                nsIDocShellTreeItem** aResult);
+  static void GetWindowTreeOwner(nsPIDOMWindowOuter* aWindow,
+                                 nsIDocShellTreeOwner** aResult);
+
+private:
+  nsresult CreateChromeWindow(const nsACString& aFeatures,
+                              nsIWebBrowserChrome* aParentChrome,
+                              uint32_t aChromeFlags,
+                              uint32_t aContextFlags,
+                              nsITabParent* aOpeningTabParent,
+                              mozIDOMWindowProxy* aOpener,
+                              nsIWebBrowserChrome** aResult);
+
+  void MaybeDisablePersistence(const nsACString& aFeatures,
+                               nsIDocShellTreeOwner* aTreeOwner);
+
+  static uint32_t CalculateChromeFlagsHelper(uint32_t aInitialFlags,
+                                             const nsACString& aFeatures,
+                                             bool &presenceFlag,
+                                             bool aDialog = false,
+                                             bool aHasChromeParent = false,
+                                             bool aChromeURL = false);
+  static uint32_t EnsureFlagsSafeForContent(uint32_t aChromeFlags,
+                                            bool aChromeURL = false);
+
+protected:
+  nsTArray<nsWatcherWindowEnumerator*> mEnumeratorList;
+  nsWatcherWindowEntry* mOldestWindow;
+  mozilla::Mutex mListLock;
+
+  nsCOMPtr<nsIWindowCreator> mWindowCreator;
+};
+
+#endif
diff --git a/embedding/components/windowwatcher/test/browser.ini b/embedding/components/windowwatcher/test/browser.ini
new file mode 100644
index 000000000..925b96e34
--- /dev/null
+++ b/embedding/components/windowwatcher/test/browser.ini
@@ -0,0 +1,9 @@
+[DEFAULT]
+tags = openwindow
+
+[browser_new_content_window_chromeflags.js]
+[browser_new_remote_window_flags.js]
+run-if = e10s
+[browser_new_content_window_from_chrome_principal.js]
+[browser_new_sized_window.js]
+skip-if = os == 'win' # Bug 1276802 - Opening windows from content on Windows might not get the size right
diff --git a/embedding/components/windowwatcher/test/browser_new_content_window_chromeflags.js b/embedding/components/windowwatcher/test/browser_new_content_window_chromeflags.js
new file mode 100644
index 000000000..887f86152
--- /dev/null
+++ b/embedding/components/windowwatcher/test/browser_new_content_window_chromeflags.js
@@ -0,0 +1,278 @@
+/**
+ * Tests that chromeFlags are set properly on windows that are
+ * being opened from content.
+ */
+
+// The following features set chrome flags on new windows and are
+// supported by web content. The schema for each property on this
+// object is as follows:
+//
+// <feature string>: {
+//   flag: <associated nsIWebBrowserChrome flag>,
+//   defaults_to: <what this feature defaults to normally>
+// }
+const ALLOWED = {
+  "toolbar": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_TOOLBAR,
+    defaults_to: true,
+  },
+  "personalbar": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_PERSONAL_TOOLBAR,
+    defaults_to: true,
+  },
+  "menubar": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_MENUBAR,
+    defaults_to: true,
+  },
+  "scrollbars": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_SCROLLBARS,
+    defaults_to: false,
+  },
+  "minimizable": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_WINDOW_MIN,
+    defaults_to: true,
+  },
+};
+
+// Construct a features string that flips all ALLOWED features
+// to not be their defaults.
+const ALLOWED_STRING = Object.keys(ALLOWED).map(feature => {
+  let toValue = ALLOWED[feature].defaults_to ? "no" : "yes";
+  return `${feature}=${toValue}`;
+}).join(",");
+
+// The following are not allowed from web content, at least
+// in the default case (since some are disabled by default
+// via the dom.disable_window_open_feature pref branch).
+const DISALLOWED = {
+  "location": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_LOCATIONBAR,
+    defaults_to: true,
+  },
+  "chrome": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_OPENAS_CHROME,
+    defaults_to: false,
+  },
+  "dialog": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_OPENAS_DIALOG,
+    defaults_to: false,
+  },
+  "private": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_PRIVATE_WINDOW,
+    defaults_to: false,
+  },
+  "non-private": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_NON_PRIVATE_WINDOW,
+    defaults_to: false,
+  },
+  // "all":
+  //   checked manually, since this is an aggregate
+  //   flag.
+  //
+  // "remote":
+  //   checked manually, since its default value will
+  //   depend on whether or not e10s is enabled by default.
+  "popup": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_WINDOW_POPUP,
+    defaults_to: false,
+  },
+  "alwaysLowered": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_WINDOW_LOWERED,
+    defaults_to: false,
+  },
+  "z-lock": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_WINDOW_LOWERED, // Renamed to alwaysLowered
+    defaults_to: false,
+  },
+  "alwaysRaised": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_WINDOW_RAISED,
+    defaults_to: false,
+  },
+  "macsuppressanimation": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_MAC_SUPPRESS_ANIMATION,
+    defaults_to: false,
+  },
+  "extrachrome": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_EXTRA,
+    defaults_to: false,
+  },
+  "centerscreen": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_CENTER_SCREEN,
+    defaults_to: false,
+  },
+  "dependent": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_DEPENDENT,
+    defaults_to: false,
+  },
+  "modal": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_MODAL,
+    defaults_to: false,
+  },
+  "titlebar": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_TITLEBAR,
+    defaults_to: true,
+  },
+  "close": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_WINDOW_CLOSE,
+    defaults_to: true,
+  },
+  "resizable": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_WINDOW_RESIZE,
+    defaults_to: true,
+  },
+  "status": {
+    flag: Ci.nsIWebBrowserChrome.CHROME_STATUSBAR,
+    defaults_to: true,
+  },
+};
+
+// Construct a features string that flips all DISALLOWED features
+// to not be their defaults.
+const DISALLOWED_STRING = Object.keys(DISALLOWED).map(feature => {
+  let toValue = DISALLOWED[feature].defaults_to ? "no" : "yes";
+  return `${feature}=${toValue}`;
+}).join(",");
+
+const FEATURES = [ALLOWED_STRING, DISALLOWED_STRING].join(",");
+
+const SCRIPT_PAGE = `data:text/html,<script>window.open("about:blank", "_blank", "${FEATURES}");</script>`;
+const SCRIPT_PAGE_FOR_CHROME_ALL = `data:text/html,<script>window.open("about:blank", "_blank", "all");</script>`;
+
+// This magic value of 2 means that by default, when content tries
+// to open a new window, it'll actually open in a new window instead
+// of a new tab.
+Services.prefs.setIntPref("browser.link.open_newwindow", 2);
+registerCleanupFunction(() => {
+  Services.prefs.clearUserPref("browser.link.open_newwindow");
+});
+
+/**
+ * Given some nsIDOMWindow for a window running in the parent
+ * process, return the nsIWebBrowserChrome chrome flags for
+ * the associated XUL window.
+ *
+ * @param win (nsIDOMWindow)
+ *        Some window in the parent process.
+ * @returns int
+ */
+function getParentChromeFlags(win) {
+  return win.QueryInterface(Ci.nsIInterfaceRequestor)
+            .getInterface(Ci.nsIWebNavigation)
+            .QueryInterface(Ci.nsIDocShellTreeItem)
+            .treeOwner
+            .QueryInterface(Ci.nsIInterfaceRequestor)
+            .getInterface(Ci.nsIXULWindow)
+            .chromeFlags;
+}
+
+/**
+ * For some chromeFlags, ensures that flags that are in the
+ * ALLOWED group were modified, and that flags in the DISALLOWED
+ * group were not modified.
+ *
+ * @param chromeFlags (int)
+ *        Some chromeFlags to check.
+ */
+function assertContentFlags(chromeFlags) {
+  for (let feature in ALLOWED) {
+    let flag = ALLOWED[feature].flag;
+
+    if (ALLOWED[feature].defaults_to) {
+      // The feature is supposed to default to true, so we should
+      // have been able to flip it off.
+      Assert.ok(!(chromeFlags & flag),
+                `Expected feature ${feature} to be disabled`);
+    } else {
+      // The feature is supposed to default to false, so we should
+      // have been able to flip it on.
+      Assert.ok((chromeFlags & flag),
+                `Expected feature ${feature} to be enabled`);
+    }
+  }
+
+  for (let feature in DISALLOWED) {
+    let flag = DISALLOWED[feature].flag;
+    if (DISALLOWED[feature].defaults_to) {
+      // The feature is supposed to default to true, so it should
+      // stay true.
+      Assert.ok((chromeFlags & flag),
+                `Expected feature ${feature} to be unchanged`);
+    } else {
+      // The feature is supposed to default to false, so it should
+      // stay false.
+      Assert.ok(!(chromeFlags & flag),
+                `Expected feature ${feature} to be unchanged`);
+    }
+  }
+}
+
+/**
+ * Opens a window from content using window.open with the
+ * features computed from ALLOWED and DISALLOWED. The computed
+ * feature string attempts to flip every feature away from their
+ * default.
+ */
+add_task(function* test_new_remote_window_flags() {
+  let newWinPromise = BrowserTestUtils.waitForNewWindow();
+
+  yield BrowserTestUtils.withNewTab({
+    gBrowser,
+    url: SCRIPT_PAGE,
+  }, function*(browser) {
+    let win = yield newWinPromise;
+    let parentChromeFlags = getParentChromeFlags(win);
+    assertContentFlags(parentChromeFlags);
+
+    if (win.gMultiProcessBrowser) {
+      Assert.ok(parentChromeFlags &
+                Ci.nsIWebBrowserChrome.CHROME_REMOTE_WINDOW,
+                "Should be remote by default");
+    } else {
+      Assert.ok(!(parentChromeFlags &
+                  Ci.nsIWebBrowserChrome.CHROME_REMOTE_WINDOW),
+                "Should not be remote by default");
+    }
+
+    // Confusingly, chromeFlags also exist in the content process
+    // as part of the TabChild, so we have to check those too.
+    let b = win.gBrowser.selectedBrowser;
+    let contentChromeFlags = yield ContentTask.spawn(b, null, function*() {
+      docShell.QueryInterface(Ci.nsIInterfaceRequestor);
+      try {
+        // This will throw if we're not a remote browser.
+        return docShell.getInterface(Ci.nsITabChild)
+                       .QueryInterface(Ci.nsIWebBrowserChrome)
+                       .chromeFlags;
+      } catch(e) {
+        // This must be a non-remote browser...
+        return docShell.QueryInterface(Ci.nsIDocShellTreeItem)
+                       .treeOwner
+                       .QueryInterface(Ci.nsIWebBrowserChrome)
+                       .chromeFlags;
+      }
+    });
+
+    assertContentFlags(contentChromeFlags);
+    Assert.ok(!(contentChromeFlags &
+                Ci.nsIWebBrowserChrome.CHROME_REMOTE_WINDOW),
+              "Should not be remote in the content process.");
+
+    yield BrowserTestUtils.closeWindow(win);
+  });
+
+  // We check "all" manually, since that's an aggregate flag
+  // and doesn't fit nicely into the ALLOWED / DISALLOWED scheme
+  newWinPromise = BrowserTestUtils.waitForNewWindow();
+
+  yield BrowserTestUtils.withNewTab({
+    gBrowser,
+    url: SCRIPT_PAGE_FOR_CHROME_ALL,
+  }, function*(browser) {
+    let win = yield newWinPromise;
+    let parentChromeFlags = getParentChromeFlags(win);
+    Assert.notEqual((parentChromeFlags & Ci.nsIWebBrowserChrome.CHROME_ALL),
+                    Ci.nsIWebBrowserChrome.CHROME_ALL,
+                    "Should not have been able to set CHROME_ALL");
+    yield BrowserTestUtils.closeWindow(win);
+  });
+});
diff --git a/embedding/components/windowwatcher/test/browser_new_content_window_from_chrome_principal.js b/embedding/components/windowwatcher/test/browser_new_content_window_from_chrome_principal.js
new file mode 100644
index 000000000..c8a24d43e
--- /dev/null
+++ b/embedding/components/windowwatcher/test/browser_new_content_window_from_chrome_principal.js
@@ -0,0 +1,34 @@
+"use strict";
+
+/**
+ * Tests that if chrome-privileged code calls .open() on an
+ * unprivileged window, that the principal in the newly
+ * opened window is appropriately set.
+ */
+add_task(function* test_chrome_opens_window() {
+  // This magic value of 2 means that by default, when content tries
+  // to open a new window, it'll actually open in a new window instead
+  // of a new tab.
+  yield SpecialPowers.pushPrefEnv({"set": [
+    ["browser.link.open_newwindow", 2],
+  ]});
+
+  let newWinPromise = BrowserTestUtils.waitForNewWindow(true, "http://example.com/");
+
+  yield ContentTask.spawn(gBrowser.selectedBrowser, null, function*() {
+    content.open("http://example.com/", "_blank");
+  });
+
+  let win = yield newWinPromise;
+  let browser = win.gBrowser.selectedBrowser;
+
+  yield ContentTask.spawn(browser, null, function*() {
+    Assert.ok(!content.document.nodePrincipal.isSystemPrincipal,
+              "We should not have a system principal.")
+    Assert.equal(content.document.nodePrincipal.origin,
+                 "http://example.com",
+                 "Should have the example.com principal");
+  });
+
+  yield BrowserTestUtils.closeWindow(win);
+});
\ No newline at end of file
diff --git a/embedding/components/windowwatcher/test/browser_new_remote_window_flags.js b/embedding/components/windowwatcher/test/browser_new_remote_window_flags.js
new file mode 100644
index 000000000..e4f3d1ddf
--- /dev/null
+++ b/embedding/components/windowwatcher/test/browser_new_remote_window_flags.js
@@ -0,0 +1,78 @@
+/**
+ * Tests that when a remote browser opens a new window that the
+ * newly opened window is also remote.
+ */
+
+const ANCHOR_PAGE = `data:text/html,<a href="about:blank" target="_blank">Click me!</a>`;
+const SCRIPT_PAGE = `data:text/html,<script>window.open("about:blank", "_blank");</script>`;
+
+// This magic value of 2 means that by default, when content tries
+// to open a new window, it'll actually open in a new window instead
+// of a new tab.
+add_task(function* setup() {
+  yield SpecialPowers.pushPrefEnv({"set": [
+    ["browser.link.open_newwindow", 2],
+  ]});
+});
+
+function assertFlags(win) {
+  let webNav = win.QueryInterface(Ci.nsIInterfaceRequestor)
+                  .getInterface(Ci.nsIWebNavigation);
+  let loadContext = webNav.QueryInterface(Ci.nsILoadContext);
+  let chromeFlags = webNav.QueryInterface(Ci.nsIDocShellTreeItem)
+                          .treeOwner
+                          .QueryInterface(Ci.nsIInterfaceRequestor)
+                          .getInterface(Ci.nsIXULWindow)
+                          .chromeFlags;
+  Assert.ok(loadContext.useRemoteTabs,
+            "Should be using remote tabs on the load context");
+  Assert.ok(chromeFlags & Ci.nsIWebBrowserChrome.CHROME_REMOTE_WINDOW,
+            "Should have the remoteness chrome flag on the window");
+}
+
+/**
+ * Content can open a window using a target="_blank" link
+ */
+add_task(function* test_new_remote_window_flags_target_blank() {
+  yield BrowserTestUtils.withNewTab({
+    gBrowser,
+    url: ANCHOR_PAGE,
+  }, function*(browser) {
+    let newWinPromise = BrowserTestUtils.waitForNewWindow();
+    yield BrowserTestUtils.synthesizeMouseAtCenter("a", {}, browser);
+    let win = yield newWinPromise;
+    assertFlags(win);
+    yield BrowserTestUtils.closeWindow(win);
+  });
+});
+
+/**
+ * Content can open a window using window.open
+ */
+add_task(function* test_new_remote_window_flags_window_open() {
+  let newWinPromise = BrowserTestUtils.waitForNewWindow();
+
+  yield BrowserTestUtils.withNewTab({
+    gBrowser,
+    url: SCRIPT_PAGE,
+  }, function*(browser) {
+    let win = yield newWinPromise;
+    assertFlags(win);
+    yield BrowserTestUtils.closeWindow(win);
+  });
+});
+
+/**
+ * Privileged content scripts can also open new windows
+ * using content.open.
+ */
+add_task(function* test_new_remote_window_flags_content_open() {
+  let newWinPromise = BrowserTestUtils.waitForNewWindow();
+  yield ContentTask.spawn(gBrowser.selectedBrowser, null, function*() {
+    content.open("about:blank", "_blank");
+  });
+
+  let win = yield newWinPromise;
+  assertFlags(win);
+  yield BrowserTestUtils.closeWindow(win);
+});
diff --git a/embedding/components/windowwatcher/test/browser_new_sized_window.js b/embedding/components/windowwatcher/test/browser_new_sized_window.js
new file mode 100644
index 000000000..f4b1890b1
--- /dev/null
+++ b/embedding/components/windowwatcher/test/browser_new_sized_window.js
@@ -0,0 +1,67 @@
+"use strict";
+
+/**
+ * Tests that content can open windows at requested dimensions
+ * of height and width.
+ */
+
+/**
+ * This utility function does most of the actual testing. We
+ * construct a feature string suitable for the passed in width
+ * and height, and then run that script in content to open the
+ * new window. When the new window comes up, this function tests
+ * to ensure that the content area of the initial browser is the
+ * requested dimensions. Finally, we also ensure that we're not
+ * persisting the position, size or sizemode of the new browser
+ * window.
+ */
+function test_dimensions({ width, height}) {
+  let features = [];
+  if (width) {
+    features.push(`width=${width}`);
+  }
+  if (height) {
+    features.push(`height=${height}`);
+  }
+  const FEATURE_STR = features.join(",");
+  const SCRIPT_PAGE = `data:text/html,<script>window.open("about:blank", "_blank", "${FEATURE_STR}");</script>`;
+
+  let newWinPromise = BrowserTestUtils.waitForNewWindow();
+
+  return BrowserTestUtils.withNewTab({
+    gBrowser,
+    url: SCRIPT_PAGE,
+  }, function*(browser) {
+    let win = yield newWinPromise;
+    let rect = win.gBrowser.selectedBrowser.getBoundingClientRect();
+
+    if (width) {
+      Assert.equal(rect.width, width, "Should have the requested width");
+    }
+
+    if (height) {
+      Assert.equal(rect.height, height, "Should have the requested height");
+    }
+
+    let treeOwner = win.QueryInterface(Ci.nsIInterfaceRequestor)
+                       .getInterface(Ci.nsIDocShell)
+                       .QueryInterface(Ci.nsIDocShellTreeItem)
+                       .treeOwner;
+    let persistPosition = {};
+    let persistSize = {};
+    let persistSizeMode = {};
+    treeOwner.getPersistence(persistPosition, persistSize, persistSizeMode);
+
+    Assert.ok(!persistPosition.value, "Should not persist position");
+    Assert.ok(!persistSize.value, "Should not persist size");
+    Assert.ok(!persistSizeMode.value, "Should not persist size mode");
+
+    yield BrowserTestUtils.closeWindow(win);
+  });
+}
+
+add_task(function* test_new_sized_window() {
+  yield test_dimensions({ width: 100 });
+  yield test_dimensions({ height: 150 });
+  yield test_dimensions({ width: 300, height: 200 });
+});
diff --git a/embedding/components/windowwatcher/test/chrome.ini b/embedding/components/windowwatcher/test/chrome.ini
new file mode 100644
index 000000000..5f3b49433
--- /dev/null
+++ b/embedding/components/windowwatcher/test/chrome.ini
@@ -0,0 +1,7 @@
+[DEFAULT]
+tags = openwindow
+
+[test_dialog_arguments.html]
+support-files =
+  file_test_dialog.html
+[test_modal_windows.html]
diff --git a/embedding/components/windowwatcher/test/file_storage_copied.html b/embedding/components/windowwatcher/test/file_storage_copied.html
new file mode 100644
index 000000000..250c7891a
--- /dev/null
+++ b/embedding/components/windowwatcher/test/file_storage_copied.html
@@ -0,0 +1,13 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+This page is opened in a new window by test_storage_copied.html.
+We need to return the sessionStorage value for the item "test-item",
+by way of postMessage.
+-->
+<head>
+<body>Opened!</body>
+<script>
+  window.postMessage(window.sessionStorage.getItem("test-item"), "*");
+</script>
+</html>
\ No newline at end of file
diff --git a/embedding/components/windowwatcher/test/file_test_dialog.html b/embedding/components/windowwatcher/test/file_test_dialog.html
new file mode 100644
index 000000000..b323ba526
--- /dev/null
+++ b/embedding/components/windowwatcher/test/file_test_dialog.html
@@ -0,0 +1,14 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+This page is opened in a new window by test_dialog_arguments. It is
+a dialog which expects a Symbol to be passed in the dialog arguments.
+Once we load, we call back into the opener with the argument we were
+passed.
+-->
+<head>
+<body>Opened!</body>
+<script>
+  window.opener.done(window.arguments[0]);
+</script>
+</html>
\ No newline at end of file
diff --git a/embedding/components/windowwatcher/test/mochitest.ini b/embedding/components/windowwatcher/test/mochitest.ini
new file mode 100644
index 000000000..42955d496
--- /dev/null
+++ b/embedding/components/windowwatcher/test/mochitest.ini
@@ -0,0 +1,12 @@
+[DEFAULT]
+tags = openwindow
+
+[test_blank_named_window.html]
+skip-if = (os == 'android') # Fennec doesn't support web content opening new windows (See bug 1277544 for details)
+[test_named_window.html]
+skip-if = (os == 'android') # Fennec doesn't support web content opening new windows (See bug 1277544 for details)
+[test_storage_copied.html]
+support-files =
+  file_storage_copied.html
+skip-if = (os == 'android') # Fennec doesn't support web content opening new windows (See bug 1277544 for details)
+
diff --git a/embedding/components/windowwatcher/test/moz.build b/embedding/components/windowwatcher/test/moz.build
new file mode 100644
index 000000000..bd6f51aff
--- /dev/null
+++ b/embedding/components/windowwatcher/test/moz.build
@@ -0,0 +1,18 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+BROWSER_CHROME_MANIFESTS += [
+    'browser.ini',
+]
+
+MOCHITEST_MANIFESTS += [
+    'mochitest.ini',
+]
+
+MOCHITEST_CHROME_MANIFESTS += [
+    'chrome.ini',
+]
+
diff --git a/embedding/components/windowwatcher/test/test_blank_named_window.html b/embedding/components/windowwatcher/test/test_blank_named_window.html
new file mode 100644
index 000000000..b45ad1f70
--- /dev/null
+++ b/embedding/components/windowwatcher/test/test_blank_named_window.html
@@ -0,0 +1,45 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that when opening a window with the reserved name _blank that the new
+window does not get that name, and that subsequent window openings with that
+name result in new windows being opened.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Test named windows</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="head.js" type="application/javascript;version=1.8"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+  <script type="application/javascript">
+    "use strict";
+    add_task(function*() {
+      // This magic value of 2 means that by default, when content tries
+      // to open a new window, it'll actually open in a new window instead
+      // of a new tab.
+      yield SpecialPowers.pushPrefEnv({"set": [
+        ["browser.link.open_newwindow", 2],
+      ]});
+
+      let win1 = window.open("data:text/html,<p>This is window 1 for test_blank_named_window.html</p>", "_blank");
+
+      let name = SpecialPowers.wrap(win1)
+                 .QueryInterface(SpecialPowers.Ci.nsIInterfaceRequestor)
+                 .getInterface(SpecialPowers.Ci.nsIWebNavigation)
+                 .QueryInterface(SpecialPowers.Ci.nsIDocShellTreeItem)
+                 .name;
+
+      is(name, "", "Should have no name");
+
+      let win2 = window.open("data:text/html,<p>This is window 2 for test_blank_named_window.html</p>", "_blank");
+      isnot(win1, win2, "Should not have gotten back the same window");
+
+      win1.close();
+      win2.close();
+    });
+  </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/embedding/components/windowwatcher/test/test_dialog_arguments.html b/embedding/components/windowwatcher/test/test_dialog_arguments.html
new file mode 100644
index 000000000..7cde69401
--- /dev/null
+++ b/embedding/components/windowwatcher/test/test_dialog_arguments.html
@@ -0,0 +1,38 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that arguments can be passed to dialogs.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Test a modal window</title>
+
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+
+  <script type="application/javascript;version=1.8">
+  const {utils: Cu, interfaces: Ci} = Components;
+
+  Cu.import("resource://gre/modules/Services.jsm");
+
+  const TEST_ITEM = Symbol("test-item");
+
+  function done(returnedItem) {
+    is(returnedItem, TEST_ITEM,
+       "Dialog should have received test item");
+    win.close();
+    SimpleTest.finish();
+  }
+
+  SimpleTest.waitForExplicitFinish();
+  let win = window.openDialog("file_test_dialog.html", "_blank", "width=100,height=100", TEST_ITEM);
+  </script>
+</head>
+<body>
+<p id="display"></p>
+<div id="content" style="display: none">
+</div>
+<pre id="test">
+</pre>
+</body>
+</html>
\ No newline at end of file
diff --git a/embedding/components/windowwatcher/test/test_modal_windows.html b/embedding/components/windowwatcher/test/test_modal_windows.html
new file mode 100644
index 000000000..8a2c03be0
--- /dev/null
+++ b/embedding/components/windowwatcher/test/test_modal_windows.html
@@ -0,0 +1,56 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that the parent can open modal windows, and that the modal window
+that is opened reports itself as being modal.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Test a modal window</title>
+
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SpawnTask.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css">
+
+  <script type="application/javascript;version=1.8">
+  const {utils: Cu, interfaces: Ci} = Components;
+
+  Cu.import("resource://gre/modules/Services.jsm");
+  Cu.import("resource://testing-common/BrowserTestUtils.jsm");
+
+  add_task(function*() {
+    BrowserTestUtils.domWindowOpened().then((win) => {
+      let treeOwner = win.QueryInterface(Ci.nsIInterfaceRequestor)
+                         .getInterface(Ci.nsIWebNavigation)
+                         .QueryInterface(Ci.nsIDocShellTreeItem)
+                         .treeOwner
+      let chromeFlags = treeOwner.QueryInterface(Ci.nsIInterfaceRequestor)
+                                 .getInterface(Ci.nsIXULWindow)
+                                 .chromeFlags;
+      ok(chromeFlags & Ci.nsIWebBrowserChrome.CHROME_MODAL,
+         "Should have the modal chrome flag");
+
+      let wbc = treeOwner.QueryInterface(Ci.nsIInterfaceRequestor)
+                         .getInterface(Ci.nsIWebBrowserChrome);
+      ok(wbc.isWindowModal(), "Should report as modal");
+
+      win.close();
+    });
+
+    let modal = window.openDialog("data:text/html,<p>This is a modal window for test_modal_windows.html</p>",
+                                  "_blank", "modal", null);
+    // Since the modal runs a nested event loop, just to be on the safe side,
+    // we'll wait a tick of the main event loop before resolving the task.
+    yield new Promise(resolve => setTimeout(resolve, 0));
+  });
+
+  </script>
+</head>
+<body>
+<p id="display"></p>
+<div id="content" style="display: none">
+</div>
+<pre id="test">
+</pre>
+</body>
+</html>
\ No newline at end of file
diff --git a/embedding/components/windowwatcher/test/test_named_window.html b/embedding/components/windowwatcher/test/test_named_window.html
new file mode 100644
index 000000000..58bd8a9cf
--- /dev/null
+++ b/embedding/components/windowwatcher/test/test_named_window.html
@@ -0,0 +1,92 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test that when content opens a new window with a name, that the
+newly opened window actually gets that name, and that subsequent
+attempts to open a window with that name will target the same
+window.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Test named windows</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="head.js" type="application/javascript;version=1.8"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+  <a href="#" id="link">Click me</a>
+
+  <script type="application/javascript">
+    "use strict";
+
+    const NAME = "my_window";
+    const TARGET_URL = "data:text/html,<html><body>test_named_window.html new window</body></html>";
+    const TARGET_URL_2 = TARGET_URL + "#2";
+    const TARGET_URL_3 = TARGET_URL + "#3";
+
+    /**
+     * Returns a Promise that resolves once some target has had
+     * some event dispatched on it.
+     *
+     * @param target
+     *        The thing to wait for the event to be dispatched
+     *        through.
+     * @param eventName
+     *        The name of the event to wait for.
+     * @returns Promise
+     */
+    function promiseEvent(target, eventName) {
+      return new Promise(resolve => {
+        target.addEventListener(eventName, function onEvent(e) {
+          target.removeEventListener(eventName, onEvent, true);
+          resolve(e);
+        }, true);
+      });
+    }
+
+    add_task(function*() {
+      // This magic value of 2 means that by default, when content tries
+      // to open a new window, it'll actually open in a new window instead
+      // of a new tab.
+      yield SpecialPowers.pushPrefEnv({"set": [
+        ["browser.link.open_newwindow", 2],
+      ]});
+
+      let win1 = window.open(TARGET_URL, "my_window");
+      yield promiseEvent(win1, "load");
+
+      let name = SpecialPowers.wrap(win1)
+                 .QueryInterface(SpecialPowers.Ci.nsIInterfaceRequestor)
+                 .getInterface(SpecialPowers.Ci.nsIWebNavigation)
+                 .QueryInterface(SpecialPowers.Ci.nsIDocShellTreeItem)
+                 .name;
+
+      is(name, NAME, "Should have the expected name");
+      is(win1.location.href, new URL(TARGET_URL).href,
+         "Should have loaded target TARGET_URL in the original window");
+
+      let hashChange = promiseEvent(win1, "hashchange");
+      let win2 = window.open(TARGET_URL_2, "my_window");
+      yield hashChange;
+
+      is(win1, win2, "Should have gotten back the same window");
+      is(win1.location.href, new URL(TARGET_URL_2).href,
+         "Should have re-targeted pre-existing window");
+
+      hashChange = promiseEvent(win1, "hashchange");
+      let link = document.getElementById("link");
+      link.setAttribute("target", NAME);
+      link.setAttribute("href", TARGET_URL_3);
+      link.click();
+
+      yield hashChange;
+
+      is(win1.location.href, new URL(TARGET_URL_3).href,
+         "Should have re-targeted pre-existing window");
+
+      win1.close();
+    });
+  </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/embedding/components/windowwatcher/test/test_storage_copied.html b/embedding/components/windowwatcher/test/test_storage_copied.html
new file mode 100644
index 000000000..27aeb51a9
--- /dev/null
+++ b/embedding/components/windowwatcher/test/test_storage_copied.html
@@ -0,0 +1,45 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test sessionStorage is copied over when a new window opens to the
+same domain as the opener.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Test storage copied</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script src="head.js" type="application/javascript;version=1.8"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+  <script type="application/javascript">
+    "use strict";
+
+    function waitForMessage(win) {
+      return new Promise(resolve => {
+        win.addEventListener("message", function onMessage(event) {
+          win.removeEventListener("message", onMessage);
+          resolve(event.data);
+        });
+      });
+    }
+
+    add_task(function*() {
+      const TEST_VALUE = "test-value";
+      // This magic value of 2 means that by default, when content tries
+      // to open a new window, it'll actually open in a new window instead
+      // of a new tab.
+      yield SpecialPowers.pushPrefEnv({"set": [
+        ["browser.link.open_newwindow", 2],
+      ]});
+
+      window.sessionStorage.setItem("test-item", TEST_VALUE);
+      let win = window.open("file_storage_copied.html", "my_window");
+      let data = yield waitForMessage(win);
+      is(data, TEST_VALUE, "Should have cloned the test value");
+      win.close();
+    });
+  </script>
+</body>
+</html>
\ No newline at end of file