Add m-esr52 at 52.6.0

18 files changed, 3249 insertions, 0 deletions

diff --git a/image/decoders/icon/android/moz.build b/image/decoders/icon/android/moz.build
new file mode 100644
index 000000000..5e58ff0b6
--- /dev/null
+++ b/image/decoders/icon/android/moz.build
@@ -0,0 +1,13 @@
+# -*- 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/.
+
+SOURCES += [
+    'nsIconChannel.cpp',
+]
+
+include('/ipc/chromium/chromium-config.mozbuild')
+
+FINAL_LIBRARY = 'xul'
diff --git a/image/decoders/icon/android/nsIconChannel.cpp b/image/decoders/icon/android/nsIconChannel.cpp
new file mode 100644
index 000000000..5670bf2f9
--- /dev/null
+++ b/image/decoders/icon/android/nsIconChannel.cpp
@@ -0,0 +1,145 @@
+/* -*- Mode: C++; tab-width: 20; 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 <stdlib.h>
+#include "mozilla/dom/ContentChild.h"
+#include "nsMimeTypes.h"
+#include "nsIURL.h"
+#include "nsXULAppAPI.h"
+#include "AndroidBridge.h"
+#include "nsIconChannel.h"
+#include "nsIStringStream.h"
+#include "nsNetUtil.h"
+#include "nsComponentManagerUtils.h"
+#include "nsNullPrincipal.h"
+
+NS_IMPL_ISUPPORTS(nsIconChannel,
+                  nsIRequest,
+                  nsIChannel)
+
+using namespace mozilla;
+using mozilla::dom::ContentChild;
+
+static nsresult
+GetIconForExtension(const nsACString& aFileExt, uint32_t aIconSize,
+                    uint8_t* const aBuf)
+{
+    if (!AndroidBridge::Bridge()) {
+        return NS_ERROR_FAILURE;
+    }
+
+    AndroidBridge::Bridge()->GetIconForExtension(aFileExt, aIconSize, aBuf);
+
+    return NS_OK;
+}
+
+static nsresult
+CallRemoteGetIconForExtension(const nsACString& aFileExt, uint32_t aIconSize,
+                              uint8_t* const aBuf)
+{
+  NS_ENSURE_TRUE(aBuf != nullptr, NS_ERROR_NULL_POINTER);
+
+  // An array has to be used to get data from remote process
+  InfallibleTArray<uint8_t> bits;
+  uint32_t bufSize = aIconSize * aIconSize * 4;
+
+  if (!ContentChild::GetSingleton()->SendGetIconForExtension(
+                     PromiseFlatCString(aFileExt), aIconSize, &bits)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  NS_ASSERTION(bits.Length() == bufSize, "Pixels array is incomplete");
+  if (bits.Length() != bufSize) {
+    return NS_ERROR_FAILURE;
+  }
+
+  memcpy(aBuf, bits.Elements(), bufSize);
+
+  return NS_OK;
+}
+
+static nsresult
+moz_icon_to_channel(nsIURI* aURI, const nsACString& aFileExt,
+                    uint32_t aIconSize, nsIChannel** aChannel)
+{
+  NS_ENSURE_TRUE(aIconSize < 256 && aIconSize > 0, NS_ERROR_UNEXPECTED);
+
+  int width = aIconSize;
+  int height = aIconSize;
+
+  // moz-icon data should have two bytes for the size,
+  // then the ARGB pixel values with pre-multiplied Alpha
+  const int channels = 4;
+  long int buf_size = 2 + channels * height * width;
+  uint8_t* const buf = (uint8_t*)moz_xmalloc(buf_size);
+  NS_ENSURE_TRUE(buf, NS_ERROR_OUT_OF_MEMORY);
+  uint8_t* out = buf;
+
+  *(out++) = width;
+  *(out++) = height;
+
+  nsresult rv;
+  if (XRE_IsParentProcess()) {
+    rv = GetIconForExtension(aFileExt, aIconSize, out);
+  } else {
+    rv = CallRemoteGetIconForExtension(aFileExt, aIconSize, out);
+  }
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Encode the RGBA data
+  const uint8_t* in = out;
+  for (int y = 0; y < height; ++y) {
+    for (int x = 0; x < width; ++x) {
+      uint8_t r = *(in++);
+      uint8_t g = *(in++);
+      uint8_t b = *(in++);
+      uint8_t a = *(in++);
+#define DO_PREMULTIPLY(c_) uint8_t(uint16_t(c_) * uint16_t(a) / uint16_t(255))
+      *(out++) = DO_PREMULTIPLY(b);
+      *(out++) = DO_PREMULTIPLY(g);
+      *(out++) = DO_PREMULTIPLY(r);
+      *(out++) = a;
+#undef DO_PREMULTIPLY
+    }
+  }
+
+  nsCOMPtr<nsIStringInputStream> stream =
+    do_CreateInstance("@mozilla.org/io/string-input-stream;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = stream->AdoptData((char*)buf, buf_size);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // nsIconProtocolHandler::NewChannel2 will provide the correct loadInfo for
+  // this iconChannel. Use the most restrictive security settings for the
+  // temporary loadInfo to make sure the channel can not be openend.
+  nsCOMPtr<nsIPrincipal> nullPrincipal = nsNullPrincipal::Create();
+  return NS_NewInputStreamChannel(aChannel,
+                                  aURI,
+                                  stream,
+                                  nullPrincipal,
+                                  nsILoadInfo::SEC_REQUIRE_SAME_ORIGIN_DATA_IS_BLOCKED,
+                                  nsIContentPolicy::TYPE_INTERNAL_IMAGE,
+                                  NS_LITERAL_CSTRING(IMAGE_ICON_MS));
+}
+
+nsresult
+nsIconChannel::Init(nsIURI* aURI)
+{
+  nsCOMPtr<nsIMozIconURI> iconURI = do_QueryInterface(aURI);
+  NS_ASSERTION(iconURI, "URI is not an nsIMozIconURI");
+
+  nsAutoCString stockIcon;
+  iconURI->GetStockIcon(stockIcon);
+
+  uint32_t desiredImageSize;
+  iconURI->GetImageSize(&desiredImageSize);
+
+  nsAutoCString iconFileExt;
+  iconURI->GetFileExtension(iconFileExt);
+
+  return moz_icon_to_channel(iconURI, iconFileExt, desiredImageSize,
+                             getter_AddRefs(mRealChannel));
+}
diff --git a/image/decoders/icon/android/nsIconChannel.h b/image/decoders/icon/android/nsIconChannel.h
new file mode 100644
index 000000000..be5542998
--- /dev/null
+++ b/image/decoders/icon/android/nsIconChannel.h
@@ -0,0 +1,46 @@
+/* -*- Mode: C++; tab-width: 20; 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/. */
+
+#ifndef mozilla_image_decoders_icon_android_nsIconChannel_h
+#define mozilla_image_decoders_icon_android_nsIconChannel_h
+
+#include "mozilla/Attributes.h"
+
+#include "nsIChannel.h"
+#include "nsIURI.h"
+#include "nsIIconURI.h"
+#include "nsCOMPtr.h"
+
+/**
+ * This class is the Android implementation of nsIconChannel.
+ * It asks Android for an icon, and creates a new channel for
+ * that file to which all calls will be proxied.
+ */
+class nsIconChannel final : public nsIChannel {
+  public:
+    NS_DECL_ISUPPORTS
+    NS_FORWARD_NSIREQUEST(mRealChannel->)
+    NS_FORWARD_NSICHANNEL(mRealChannel->)
+
+    nsIconChannel() { }
+
+    /**
+     * Called by nsIconProtocolHandler after it creates this channel.
+     * Must be called before calling any other function on this object.
+     * If this method fails, no other function must be called on this object.
+     */
+    nsresult Init(nsIURI* aURI);
+
+  private:
+    ~nsIconChannel() { }
+
+    /**
+     * The channel to the temp icon file (e.g. to /tmp/2qy9wjqw.html).
+     * Will always be non-null after a successful Init.
+     */
+    nsCOMPtr<nsIChannel> mRealChannel;
+};
+
+#endif // mozilla_image_decoders_icon_android_nsIconChannel_h
diff --git a/image/decoders/icon/gtk/moz.build b/image/decoders/icon/gtk/moz.build
new file mode 100644
index 000000000..a8116ca87
--- /dev/null
+++ b/image/decoders/icon/gtk/moz.build
@@ -0,0 +1,16 @@
+# -*- 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/.
+
+SOURCES += [
+    'nsIconChannel.cpp',
+]
+
+FINAL_LIBRARY = 'xul'
+
+if CONFIG['MOZ_ENABLE_GNOMEUI']:
+    CXXFLAGS += CONFIG['MOZ_GNOMEUI_CFLAGS']
+else:
+    CXXFLAGS += CONFIG['TK_CFLAGS']
diff --git a/image/decoders/icon/gtk/nsIconChannel.cpp b/image/decoders/icon/gtk/nsIconChannel.cpp
new file mode 100644
index 000000000..b014e4c04
--- /dev/null
+++ b/image/decoders/icon/gtk/nsIconChannel.cpp
@@ -0,0 +1,427 @@
+/* vim:set ts=2 sw=2 sts=2 cin et: */
+/* 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 "nsIconChannel.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "mozilla/DebugOnly.h"
+#include "mozilla/EndianUtils.h"
+#include <algorithm>
+
+#ifdef MOZ_ENABLE_GIO
+#include <gio/gio.h>
+#endif
+
+#include <gtk/gtk.h>
+
+#include "nsMimeTypes.h"
+#include "nsIMIMEService.h"
+
+#include "nsServiceManagerUtils.h"
+
+#include "nsNetUtil.h"
+#include "nsComponentManagerUtils.h"
+#include "nsIStringStream.h"
+#include "nsServiceManagerUtils.h"
+#include "nsNullPrincipal.h"
+#include "nsIURL.h"
+#include "prlink.h"
+
+NS_IMPL_ISUPPORTS(nsIconChannel,
+                  nsIRequest,
+                  nsIChannel)
+
+static nsresult
+moz_gdk_pixbuf_to_channel(GdkPixbuf* aPixbuf, nsIURI* aURI,
+                          nsIChannel** aChannel)
+{
+  int width = gdk_pixbuf_get_width(aPixbuf);
+  int height = gdk_pixbuf_get_height(aPixbuf);
+  NS_ENSURE_TRUE(height < 256 && width < 256 && height > 0 && width > 0 &&
+                 gdk_pixbuf_get_colorspace(aPixbuf) == GDK_COLORSPACE_RGB &&
+                 gdk_pixbuf_get_bits_per_sample(aPixbuf) == 8 &&
+                 gdk_pixbuf_get_has_alpha(aPixbuf) &&
+                 gdk_pixbuf_get_n_channels(aPixbuf) == 4,
+                 NS_ERROR_UNEXPECTED);
+
+  const int n_channels = 4;
+  gsize buf_size = 2 + n_channels * height * width;
+  uint8_t* const buf = (uint8_t*)moz_xmalloc(buf_size);
+  NS_ENSURE_TRUE(buf, NS_ERROR_OUT_OF_MEMORY);
+  uint8_t* out = buf;
+
+  *(out++) = width;
+  *(out++) = height;
+
+  const guchar* const pixels = gdk_pixbuf_get_pixels(aPixbuf);
+  int rowextra = gdk_pixbuf_get_rowstride(aPixbuf) - width * n_channels;
+
+  // encode the RGB data and the A data
+  const guchar* in = pixels;
+  for (int y = 0; y < height; ++y, in += rowextra) {
+    for (int x = 0; x < width; ++x) {
+      uint8_t r = *(in++);
+      uint8_t g = *(in++);
+      uint8_t b = *(in++);
+      uint8_t a = *(in++);
+#define DO_PREMULTIPLY(c_) uint8_t(uint16_t(c_) * uint16_t(a) / uint16_t(255))
+#if MOZ_LITTLE_ENDIAN
+      *(out++) = DO_PREMULTIPLY(b);
+      *(out++) = DO_PREMULTIPLY(g);
+      *(out++) = DO_PREMULTIPLY(r);
+      *(out++) = a;
+#else
+      *(out++) = a;
+      *(out++) = DO_PREMULTIPLY(r);
+      *(out++) = DO_PREMULTIPLY(g);
+      *(out++) = DO_PREMULTIPLY(b);
+#endif
+#undef DO_PREMULTIPLY
+    }
+  }
+
+  NS_ASSERTION(out == buf + buf_size, "size miscalculation");
+
+  nsresult rv;
+  nsCOMPtr<nsIStringInputStream> stream =
+    do_CreateInstance("@mozilla.org/io/string-input-stream;1", &rv);
+
+  // Prevent the leaking of buf
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    free(buf);
+    return rv;
+  }
+
+  // stream takes ownership of buf and will free it on destruction.
+  // This function cannot fail.
+  rv = stream->AdoptData((char*)buf, buf_size);
+
+  // If this no longer holds then re-examine buf's lifetime.
+  MOZ_ASSERT(NS_SUCCEEDED(rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // nsIconProtocolHandler::NewChannel2 will provide the correct loadInfo for
+  // this iconChannel. Use the most restrictive security settings for the
+  // temporary loadInfo to make sure the channel can not be openend.
+  nsCOMPtr<nsIPrincipal> nullPrincipal = nsNullPrincipal::Create();
+  return NS_NewInputStreamChannel(aChannel,
+                                  aURI,
+                                  stream,
+                                  nullPrincipal,
+                                  nsILoadInfo::SEC_REQUIRE_SAME_ORIGIN_DATA_IS_BLOCKED,
+                                  nsIContentPolicy::TYPE_INTERNAL_IMAGE,
+                                  NS_LITERAL_CSTRING(IMAGE_ICON_MS));
+}
+
+static GtkWidget* gProtoWindow = nullptr;
+static GtkWidget* gStockImageWidget = nullptr;
+
+static void
+ensure_stock_image_widget()
+{
+  // Only the style of the GtkImage needs to be used, but the widget is kept
+  // to track dynamic style changes.
+  if (!gProtoWindow) {
+    gProtoWindow = gtk_window_new(GTK_WINDOW_POPUP);
+    GtkWidget* protoLayout = gtk_fixed_new();
+    gtk_container_add(GTK_CONTAINER(gProtoWindow), protoLayout);
+
+    gStockImageWidget = gtk_image_new();
+    gtk_container_add(GTK_CONTAINER(protoLayout), gStockImageWidget);
+
+    gtk_widget_ensure_style(gStockImageWidget);
+  }
+}
+
+static GtkIconSize
+moz_gtk_icon_size(const char* name)
+{
+  if (strcmp(name, "button") == 0) {
+    return GTK_ICON_SIZE_BUTTON;
+  }
+
+  if (strcmp(name, "menu") == 0) {
+    return GTK_ICON_SIZE_MENU;
+  }
+
+  if (strcmp(name, "toolbar") == 0) {
+    return GTK_ICON_SIZE_LARGE_TOOLBAR;
+  }
+
+  if (strcmp(name, "toolbarsmall") == 0) {
+    return GTK_ICON_SIZE_SMALL_TOOLBAR;
+  }
+
+  if (strcmp(name, "dnd") == 0) {
+    return GTK_ICON_SIZE_DND;
+  }
+
+  if (strcmp(name, "dialog") == 0) {
+    return GTK_ICON_SIZE_DIALOG;
+  }
+
+  return GTK_ICON_SIZE_MENU;
+}
+
+#ifdef MOZ_ENABLE_GIO
+static int32_t
+GetIconSize(nsIMozIconURI* aIconURI)
+{
+  nsAutoCString iconSizeString;
+
+  aIconURI->GetIconSize(iconSizeString);
+  if (iconSizeString.IsEmpty()) {
+    uint32_t size;
+    mozilla::DebugOnly<nsresult> rv = aIconURI->GetImageSize(&size);
+    NS_ASSERTION(NS_SUCCEEDED(rv), "GetImageSize failed");
+    return size;
+  } else {
+    int size;
+
+    GtkIconSize icon_size = moz_gtk_icon_size(iconSizeString.get());
+    gtk_icon_size_lookup(icon_size, &size, nullptr);
+    return size;
+  }
+}
+
+/* Scale icon buffer to preferred size */
+static nsresult
+ScaleIconBuf(GdkPixbuf** aBuf, int32_t iconSize)
+{
+  // Scale buffer only if width or height differ from preferred size
+  if (gdk_pixbuf_get_width(*aBuf)  != iconSize &&
+      gdk_pixbuf_get_height(*aBuf) != iconSize) {
+    GdkPixbuf* scaled = gdk_pixbuf_scale_simple(*aBuf, iconSize, iconSize,
+                                                GDK_INTERP_BILINEAR);
+    // replace original buffer by scaled
+    g_object_unref(*aBuf);
+    *aBuf = scaled;
+    if (!scaled) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+nsIconChannel::InitWithGIO(nsIMozIconURI* aIconURI)
+{
+  GIcon *icon = nullptr;
+  nsCOMPtr<nsIURL> fileURI;
+
+  // Read icon content
+  aIconURI->GetIconURL(getter_AddRefs(fileURI));
+
+  // Get icon for file specified by URI
+  if (fileURI) {
+    bool isFile;
+    nsAutoCString spec;
+    fileURI->GetAsciiSpec(spec);
+    if (NS_SUCCEEDED(fileURI->SchemeIs("file", &isFile)) && isFile) {
+      GFile* file = g_file_new_for_uri(spec.get());
+      GFileInfo* fileInfo = g_file_query_info(file,
+                                              G_FILE_ATTRIBUTE_STANDARD_ICON,
+                                              G_FILE_QUERY_INFO_NONE,
+                                              nullptr, nullptr);
+      g_object_unref(file);
+      if (fileInfo) {
+        // icon from g_content_type_get_icon doesn't need unref
+        icon = g_file_info_get_icon(fileInfo);
+        if (icon) {
+          g_object_ref(icon);
+        }
+        g_object_unref(fileInfo);
+      }
+    }
+  }
+
+  // Try to get icon by using MIME type
+  if (!icon) {
+    nsAutoCString type;
+    aIconURI->GetContentType(type);
+    // Try to get MIME type from file extension by using nsIMIMEService
+    if (type.IsEmpty()) {
+      nsCOMPtr<nsIMIMEService> ms(do_GetService("@mozilla.org/mime;1"));
+      if (ms) {
+        nsAutoCString fileExt;
+        aIconURI->GetFileExtension(fileExt);
+        ms->GetTypeFromExtension(fileExt, type);
+      }
+    }
+    char* ctype = nullptr; // character representation of content type
+    if (!type.IsEmpty()) {
+      ctype = g_content_type_from_mime_type(type.get());
+    }
+    if (ctype) {
+      icon = g_content_type_get_icon(ctype);
+      g_free(ctype);
+    }
+  }
+
+  // Get default icon theme
+  GtkIconTheme* iconTheme = gtk_icon_theme_get_default();
+  GtkIconInfo* iconInfo = nullptr;
+  // Get icon size
+  int32_t iconSize = GetIconSize(aIconURI);
+
+  if (icon) {
+    // Use icon and theme to get GtkIconInfo
+    iconInfo = gtk_icon_theme_lookup_by_gicon(iconTheme,
+                                              icon, iconSize,
+                                              (GtkIconLookupFlags)0);
+    g_object_unref(icon);
+  }
+
+  if (!iconInfo) {
+    // Mozilla's mimetype lookup failed. Try the "unknown" icon.
+    iconInfo = gtk_icon_theme_lookup_icon(iconTheme,
+                                          "unknown", iconSize,
+                                          (GtkIconLookupFlags)0);
+    if (!iconInfo) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+  }
+
+  // Create a GdkPixbuf buffer containing icon and scale it
+  GdkPixbuf* buf = gtk_icon_info_load_icon(iconInfo, nullptr);
+  gtk_icon_info_free(iconInfo);
+  if (!buf) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsresult rv = ScaleIconBuf(&buf, iconSize);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = moz_gdk_pixbuf_to_channel(buf, aIconURI,
+                                 getter_AddRefs(mRealChannel));
+  g_object_unref(buf);
+  return rv;
+}
+#endif // MOZ_ENABLE_GIO
+
+nsresult
+nsIconChannel::Init(nsIURI* aURI)
+{
+  nsCOMPtr<nsIMozIconURI> iconURI = do_QueryInterface(aURI);
+  NS_ASSERTION(iconURI, "URI is not an nsIMozIconURI");
+
+  nsAutoCString stockIcon;
+  iconURI->GetStockIcon(stockIcon);
+  if (stockIcon.IsEmpty()) {
+#ifdef MOZ_ENABLE_GIO
+    return InitWithGIO(iconURI);
+#else
+    return NS_ERROR_NOT_AVAILABLE;
+#endif
+  }
+
+  // Search for stockIcon
+  nsAutoCString iconSizeString;
+  iconURI->GetIconSize(iconSizeString);
+
+  nsAutoCString iconStateString;
+  iconURI->GetIconState(iconStateString);
+
+  GtkIconSize icon_size = moz_gtk_icon_size(iconSizeString.get());
+  GtkStateType state = iconStateString.EqualsLiteral("disabled") ?
+    GTK_STATE_INSENSITIVE : GTK_STATE_NORMAL;
+
+  // First lookup the icon by stock id and text direction.
+  GtkTextDirection direction = GTK_TEXT_DIR_NONE;
+  if (StringEndsWith(stockIcon, NS_LITERAL_CSTRING("-ltr"))) {
+    direction = GTK_TEXT_DIR_LTR;
+  } else if (StringEndsWith(stockIcon, NS_LITERAL_CSTRING("-rtl"))) {
+    direction = GTK_TEXT_DIR_RTL;
+  }
+
+  bool forceDirection = direction != GTK_TEXT_DIR_NONE;
+  nsAutoCString stockID;
+  bool useIconName = false;
+  if (!forceDirection) {
+    direction = gtk_widget_get_default_direction();
+    stockID = stockIcon;
+  } else {
+    // GTK versions < 2.22 use icon names from concatenating stock id with
+    // -(rtl|ltr), which is how the moz-icon stock name is interpreted here.
+    stockID = Substring(stockIcon, 0, stockIcon.Length() - 4);
+    // However, if we lookup bidi icons by the stock name, then GTK versions
+    // >= 2.22 will use a bidi lookup convention that most icon themes do not
+    // yet follow.  Therefore, we first check to see if the theme supports the
+    // old icon name as this will have bidi support (if found).
+    GtkIconTheme* icon_theme = gtk_icon_theme_get_default();
+    // Micking what gtk_icon_set_render_icon does with sizes, though it's not
+    // critical as icons will be scaled to suit size.  It just means we follow
+    // the same pathes and so share caches.
+    gint width, height;
+    if (gtk_icon_size_lookup(icon_size, &width, &height)) {
+      gint size = std::min(width, height);
+      // We use gtk_icon_theme_lookup_icon() without
+      // GTK_ICON_LOOKUP_USE_BUILTIN instead of gtk_icon_theme_has_icon() so
+      // we don't pick up fallback icons added by distributions for backward
+      // compatibility.
+      GtkIconInfo* icon =
+        gtk_icon_theme_lookup_icon(icon_theme, stockIcon.get(),
+                                   size, (GtkIconLookupFlags)0);
+      if (icon) {
+        useIconName = true;
+        gtk_icon_info_free(icon);
+      }
+    }
+  }
+
+  ensure_stock_image_widget();
+  GtkStyle* style = gtk_widget_get_style(gStockImageWidget);
+  GtkIconSet* icon_set = nullptr;
+  if (!useIconName) {
+    icon_set = gtk_style_lookup_icon_set(style, stockID.get());
+  }
+
+  if (!icon_set) {
+    // Either we have choosen icon-name lookup for a bidi icon, or stockIcon is
+    // not a stock id so we assume it is an icon name.
+    useIconName = true;
+    // Creating a GtkIconSet is a convenient way to allow the style to
+    // render the icon, possibly with variations suitable for insensitive
+    // states.
+    icon_set = gtk_icon_set_new();
+    GtkIconSource* icon_source = gtk_icon_source_new();
+
+    gtk_icon_source_set_icon_name(icon_source, stockIcon.get());
+    gtk_icon_set_add_source(icon_set, icon_source);
+    gtk_icon_source_free(icon_source);
+  }
+
+  GdkPixbuf* icon =
+    gtk_icon_set_render_icon(icon_set, style, direction, state,
+                             icon_size, gStockImageWidget, nullptr);
+  if (useIconName) {
+    gtk_icon_set_unref(icon_set);
+  }
+
+  // According to documentation, gtk_icon_set_render_icon() never returns
+  // nullptr, but it does return nullptr when we have the problem reported
+  // here: https://bugzilla.gnome.org/show_bug.cgi?id=629878#c13
+  if (!icon) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  nsresult rv = moz_gdk_pixbuf_to_channel(icon, iconURI,
+                                          getter_AddRefs(mRealChannel));
+
+  g_object_unref(icon);
+
+  return rv;
+}
+
+void
+nsIconChannel::Shutdown() {
+  if (gProtoWindow) {
+    gtk_widget_destroy(gProtoWindow);
+    gProtoWindow = nullptr;
+    gStockImageWidget = nullptr;
+  }
+}
diff --git a/image/decoders/icon/gtk/nsIconChannel.h b/image/decoders/icon/gtk/nsIconChannel.h
new file mode 100644
index 000000000..5d59272d5
--- /dev/null
+++ b/image/decoders/icon/gtk/nsIconChannel.h
@@ -0,0 +1,43 @@
+/* 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 mozilla_image_decoders_icon_gtk_nsIconChannel_h
+#define mozilla_image_decoders_icon_gtk_nsIconChannel_h
+
+#include "mozilla/Attributes.h"
+
+#include "nsIChannel.h"
+#include "nsIStreamListener.h"
+#include "nsIURI.h"
+#include "nsIIconURI.h"
+#include "nsCOMPtr.h"
+
+/// This class is the gnome implementation of nsIconChannel. It basically asks
+/// gtk/gnome for an icon, saves it as a tmp icon, and creates a new channel for
+/// that file to which all calls will be proxied.
+class nsIconChannel final : public nsIChannel
+{
+  public:
+    NS_DECL_ISUPPORTS
+    NS_FORWARD_NSIREQUEST(mRealChannel->)
+    NS_FORWARD_NSICHANNEL(mRealChannel->)
+
+    nsIconChannel() { }
+
+    static void Shutdown();
+
+    /// Called by nsIconProtocolHandler after it creates this channel.
+    /// Must be called before calling any other function on this object.
+    /// If this method fails, no other function must be called on this object.
+    nsresult Init(nsIURI* aURI);
+  private:
+    ~nsIconChannel() { }
+    /// The channel to the temp icon file (e.g. to /tmp/2qy9wjqw.html).
+    /// Will always be non-null after a successful Init.
+    nsCOMPtr<nsIChannel> mRealChannel;
+
+    nsresult InitWithGIO(nsIMozIconURI* aIconURI);
+};
+
+#endif // mozilla_image_decoders_icon_gtk_nsIconChannel_h
diff --git a/image/decoders/icon/mac/moz.build b/image/decoders/icon/mac/moz.build
new file mode 100644
index 000000000..158c326ea
--- /dev/null
+++ b/image/decoders/icon/mac/moz.build
@@ -0,0 +1,11 @@
+# -*- 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/.
+
+SOURCES += [
+    'nsIconChannelCocoa.mm',
+]
+
+FINAL_LIBRARY = 'xul'
diff --git a/image/decoders/icon/mac/nsIconChannel.h b/image/decoders/icon/mac/nsIconChannel.h
new file mode 100644
index 000000000..9fef17119
--- /dev/null
+++ b/image/decoders/icon/mac/nsIconChannel.h
@@ -0,0 +1,59 @@
+/* -*- 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/. */
+
+#ifndef mozilla_image_encoders_icon_mac_nsIconChannel_h
+#define mozilla_image_encoders_icon_mac_nsIconChannel_h
+
+#include "mozilla/Attributes.h"
+
+#include "nsCOMPtr.h"
+#include "nsXPIDLString.h"
+#include "nsIChannel.h"
+#include "nsILoadGroup.h"
+#include "nsILoadInfo.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsIInputStreamPump.h"
+#include "nsIStreamListener.h"
+#include "nsIURI.h"
+
+class nsIFile;
+
+class nsIconChannel final : public nsIChannel, public nsIStreamListener
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIREQUEST
+  NS_DECL_NSICHANNEL
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+
+  nsIconChannel();
+
+  nsresult Init(nsIURI* uri);
+
+protected:
+  virtual ~nsIconChannel();
+
+  nsCOMPtr<nsIURI> mUrl;
+  nsCOMPtr<nsIURI> mOriginalURI;
+  nsCOMPtr<nsILoadGroup> mLoadGroup;
+  nsCOMPtr<nsIInterfaceRequestor> mCallbacks;
+  nsCOMPtr<nsISupports>  mOwner;
+  nsCOMPtr<nsILoadInfo>  mLoadInfo;
+
+  nsCOMPtr<nsIInputStreamPump> mPump;
+  nsCOMPtr<nsIStreamListener>  mListener;
+
+  nsresult MakeInputStream(nsIInputStream** _retval, bool nonBlocking);
+
+  nsresult ExtractIconInfoFromUrl(nsIFile** aLocalFile,
+                                  uint32_t* aDesiredImageSize,
+                                  nsACString& aContentType,
+                                  nsACString& aFileExtension);
+};
+
+#endif // mozilla_image_encoders_icon_mac_nsIconChannel_h
diff --git a/image/decoders/icon/mac/nsIconChannelCocoa.mm b/image/decoders/icon/mac/nsIconChannelCocoa.mm
new file mode 100644
index 000000000..9c2686cdd
--- /dev/null
+++ b/image/decoders/icon/mac/nsIconChannelCocoa.mm
@@ -0,0 +1,565 @@
+/* -*- 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 "nsContentUtils.h"
+#include "nsIconChannel.h"
+#include "mozilla/EndianUtils.h"
+#include "nsIIconURI.h"
+#include "nsIServiceManager.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsXPIDLString.h"
+#include "nsMimeTypes.h"
+#include "nsMemory.h"
+#include "nsIStringStream.h"
+#include "nsIURL.h"
+#include "nsNetCID.h"
+#include "nsIPipe.h"
+#include "nsIOutputStream.h"
+#include "nsIMIMEService.h"
+#include "nsCExternalHandlerService.h"
+#include "nsILocalFileMac.h"
+#include "nsIFileURL.h"
+#include "nsTArray.h"
+#include "nsObjCExceptions.h"
+#include "nsProxyRelease.h"
+#include "nsContentSecurityManager.h"
+
+#include <Cocoa/Cocoa.h>
+
+// nsIconChannel methods
+nsIconChannel::nsIconChannel()
+{
+}
+
+nsIconChannel::~nsIconChannel()
+{
+  if (mLoadInfo) {
+    NS_ReleaseOnMainThread(mLoadInfo.forget());
+  }
+}
+
+NS_IMPL_ISUPPORTS(nsIconChannel,
+                  nsIChannel,
+                  nsIRequest,
+                  nsIRequestObserver,
+                  nsIStreamListener)
+
+nsresult
+nsIconChannel::Init(nsIURI* uri)
+{
+  NS_ASSERTION(uri, "no uri");
+  mUrl = uri;
+  mOriginalURI = uri;
+  nsresult rv;
+  mPump = do_CreateInstance(NS_INPUTSTREAMPUMP_CONTRACTID, &rv);
+  return rv;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIRequest methods:
+
+NS_IMETHODIMP
+nsIconChannel::GetName(nsACString& result)
+{
+  return mUrl->GetSpec(result);
+}
+
+NS_IMETHODIMP
+nsIconChannel::IsPending(bool* result)
+{
+  return mPump->IsPending(result);
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetStatus(nsresult* status)
+{
+  return mPump->GetStatus(status);
+}
+
+NS_IMETHODIMP
+nsIconChannel::Cancel(nsresult status)
+{
+  return mPump->Cancel(status);
+}
+
+NS_IMETHODIMP
+nsIconChannel::Suspend(void)
+{
+  return mPump->Suspend();
+}
+
+NS_IMETHODIMP
+nsIconChannel::Resume(void)
+{
+  return mPump->Resume();
+}
+
+// nsIRequestObserver methods
+NS_IMETHODIMP
+nsIconChannel::OnStartRequest(nsIRequest* aRequest,
+                                            nsISupports* aContext)
+{
+  if (mListener) {
+    return mListener->OnStartRequest(this, aContext);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::OnStopRequest(nsIRequest* aRequest,
+                                           nsISupports* aContext,
+                                           nsresult aStatus)
+{
+  if (mListener) {
+    mListener->OnStopRequest(this, aContext, aStatus);
+    mListener = nullptr;
+  }
+
+  // Remove from load group
+  if (mLoadGroup) {
+    mLoadGroup->RemoveRequest(this, nullptr, aStatus);
+  }
+
+  return NS_OK;
+}
+
+// nsIStreamListener methods
+NS_IMETHODIMP
+nsIconChannel::OnDataAvailable(nsIRequest* aRequest,
+                                             nsISupports* aContext,
+                                             nsIInputStream* aStream,
+                                             uint64_t aOffset,
+                                             uint32_t aCount)
+{
+  if (mListener) {
+    return mListener->OnDataAvailable(this, aContext, aStream, aOffset, aCount);
+  }
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIChannel methods:
+
+NS_IMETHODIMP
+nsIconChannel::GetOriginalURI(nsIURI** aURI)
+{
+  *aURI = mOriginalURI;
+  NS_ADDREF(*aURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetOriginalURI(nsIURI* aURI)
+{
+  NS_ENSURE_ARG_POINTER(aURI);
+  mOriginalURI = aURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetURI(nsIURI** aURI)
+{
+  *aURI = mUrl;
+  NS_IF_ADDREF(*aURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::Open(nsIInputStream** _retval)
+{
+  return MakeInputStream(_retval, false);
+}
+
+NS_IMETHODIMP
+nsIconChannel::Open2(nsIInputStream** aStream)
+{
+  nsCOMPtr<nsIStreamListener> listener;
+  nsresult rv = nsContentSecurityManager::doContentSecurityCheck(this, listener);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return Open(aStream);
+}
+
+nsresult
+nsIconChannel::ExtractIconInfoFromUrl(nsIFile** aLocalFile,
+                                               uint32_t* aDesiredImageSize,
+                                               nsACString& aContentType,
+                                               nsACString& aFileExtension)
+{
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIMozIconURI> iconURI (do_QueryInterface(mUrl, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  iconURI->GetImageSize(aDesiredImageSize);
+  iconURI->GetContentType(aContentType);
+  iconURI->GetFileExtension(aFileExtension);
+
+  nsCOMPtr<nsIURL> url;
+  rv = iconURI->GetIconURL(getter_AddRefs(url));
+  if (NS_FAILED(rv) || !url) return NS_OK;
+
+  nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(url, &rv);
+  if (NS_FAILED(rv) || !fileURL) return NS_OK;
+
+  nsCOMPtr<nsIFile> file;
+  rv = fileURL->GetFile(getter_AddRefs(file));
+  if (NS_FAILED(rv) || !file) return NS_OK;
+
+  nsCOMPtr<nsILocalFileMac> localFileMac (do_QueryInterface(file, &rv));
+  if (NS_FAILED(rv) || !localFileMac) return NS_OK;
+
+  *aLocalFile = file;
+  NS_IF_ADDREF(*aLocalFile);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::AsyncOpen(nsIStreamListener* aListener,
+                                       nsISupports* ctxt)
+{
+  MOZ_ASSERT(!mLoadInfo ||
+             mLoadInfo->GetSecurityMode() == 0 ||
+             mLoadInfo->GetInitialSecurityCheckDone() ||
+             (mLoadInfo->GetSecurityMode() == nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_DATA_IS_NULL &&
+              nsContentUtils::IsSystemPrincipal(mLoadInfo->LoadingPrincipal())),
+             "security flags in loadInfo but asyncOpen2() not called");
+
+  nsCOMPtr<nsIInputStream> inStream;
+  nsresult rv = MakeInputStream(getter_AddRefs(inStream), true);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Init our stream pump
+  rv = mPump->Init(inStream, int64_t(-1), int64_t(-1), 0, 0, false);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = mPump->AsyncRead(this, ctxt);
+  if (NS_SUCCEEDED(rv)) {
+    // Store our real listener
+    mListener = aListener;
+    // Add ourself to the load group, if available
+    if (mLoadGroup) {
+      mLoadGroup->AddRequest(this, nullptr);
+    }
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsIconChannel::AsyncOpen2(nsIStreamListener* aListener)
+{
+  nsCOMPtr<nsIStreamListener> listener = aListener;
+  nsresult rv = nsContentSecurityManager::doContentSecurityCheck(this, listener);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return AsyncOpen(listener, nullptr);
+}
+
+nsresult
+nsIconChannel::MakeInputStream(nsIInputStream** _retval,
+                                        bool aNonBlocking)
+{
+  NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSRESULT;
+
+  nsXPIDLCString contentType;
+  nsAutoCString fileExt;
+  nsCOMPtr<nsIFile> fileloc; // file we want an icon for
+  uint32_t desiredImageSize;
+  nsresult rv = ExtractIconInfoFromUrl(getter_AddRefs(fileloc),
+                                       &desiredImageSize, contentType, fileExt);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool fileExists = false;
+  if (fileloc) {
+    // ensure that we DO NOT resolve aliases, very important for file views
+    fileloc->SetFollowLinks(false);
+    fileloc->Exists(&fileExists);
+  }
+
+  NSImage* iconImage = nil;
+
+  // first try to get the icon from the file if it exists
+  if (fileExists) {
+    nsCOMPtr<nsILocalFileMac> localFileMac(do_QueryInterface(fileloc, &rv));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    CFURLRef macURL;
+    if (NS_SUCCEEDED(localFileMac->GetCFURL(&macURL))) {
+      iconImage = [[NSWorkspace sharedWorkspace]
+                   iconForFile:[(NSURL*)macURL path]];
+      ::CFRelease(macURL);
+    }
+  }
+
+  // if we don't have an icon yet try to get one by extension
+  if (!iconImage && !fileExt.IsEmpty()) {
+    NSString* fileExtension = [NSString stringWithUTF8String:fileExt.get()];
+    iconImage = [[NSWorkspace sharedWorkspace] iconForFileType:fileExtension];
+  }
+
+  // If we still don't have an icon, get the generic document icon.
+  if (!iconImage) {
+    iconImage = [[NSWorkspace sharedWorkspace]
+                 iconForFileType:NSFileTypeUnknown];
+  }
+
+  if (!iconImage) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // we have an icon now, size it
+  NSRect desiredSizeRect = NSMakeRect(0, 0, desiredImageSize, desiredImageSize);
+  [iconImage setSize:desiredSizeRect.size];
+
+  [iconImage lockFocus];
+  NSBitmapImageRep* bitmapRep = [[[NSBitmapImageRep alloc]
+                                  initWithFocusedViewRect:desiredSizeRect]
+                                  autorelease];
+  [iconImage unlockFocus];
+
+  // we expect the following things to be true about our bitmapRep
+  NS_ENSURE_TRUE(![bitmapRep isPlanar] &&
+                 // Not necessarily: on a HiDPI-capable system, we'll get
+                 // a 2x bitmap
+                 // (unsigned int)[bitmapRep bytesPerPlane] ==
+                 //    desiredImageSize * desiredImageSize * 4 &&
+                 [bitmapRep bitsPerPixel] == 32 &&
+                 [bitmapRep samplesPerPixel] == 4 &&
+                 [bitmapRep hasAlpha] == YES,
+                 NS_ERROR_UNEXPECTED);
+
+  // check what size we actually got, and ensure it isn't too big to return
+  uint32_t actualImageSize = [bitmapRep bytesPerRow] / 4;
+  NS_ENSURE_TRUE(actualImageSize < 256, NS_ERROR_UNEXPECTED);
+
+  // now we can validate the amount of data
+  NS_ENSURE_TRUE((unsigned int)[bitmapRep bytesPerPlane] ==
+                 actualImageSize * actualImageSize * 4,
+                 NS_ERROR_UNEXPECTED);
+
+  // rgba, pre-multiplied data
+  uint8_t* bitmapRepData = (uint8_t*)[bitmapRep bitmapData];
+
+  // create our buffer
+  int32_t bufferCapacity = 2 + [bitmapRep bytesPerPlane];
+  AutoTArray<uint8_t, 3 + 16 * 16 * 5> iconBuffer; // initial size is for
+                                                     // 16x16
+  iconBuffer.SetLength(bufferCapacity);
+
+  uint8_t* iconBufferPtr = iconBuffer.Elements();
+
+  // write header data into buffer
+  *iconBufferPtr++ = actualImageSize;
+  *iconBufferPtr++ = actualImageSize;
+
+  uint32_t dataCount = [bitmapRep bytesPerPlane];
+  uint32_t index = 0;
+  while (index < dataCount) {
+    // get data from the bitmap
+    uint8_t r = bitmapRepData[index++];
+    uint8_t g = bitmapRepData[index++];
+    uint8_t b = bitmapRepData[index++];
+    uint8_t a = bitmapRepData[index++];
+
+    // write data out to our buffer
+    // non-cairo uses native image format, but the A channel is ignored.
+    // cairo uses ARGB (highest to lowest bits)
+#if MOZ_LITTLE_ENDIAN
+    *iconBufferPtr++ = b;
+    *iconBufferPtr++ = g;
+    *iconBufferPtr++ = r;
+    *iconBufferPtr++ = a;
+#else
+    *iconBufferPtr++ = a;
+    *iconBufferPtr++ = r;
+    *iconBufferPtr++ = g;
+    *iconBufferPtr++ = b;
+#endif
+  }
+
+  NS_ASSERTION(iconBufferPtr == iconBuffer.Elements() + bufferCapacity,
+               "buffer size miscalculation");
+
+  // Now, create a pipe and stuff our data into it
+  nsCOMPtr<nsIInputStream> inStream;
+  nsCOMPtr<nsIOutputStream> outStream;
+  rv = NS_NewPipe(getter_AddRefs(inStream), getter_AddRefs(outStream),
+                  bufferCapacity, bufferCapacity, aNonBlocking);
+
+  if (NS_SUCCEEDED(rv)) {
+    uint32_t written;
+    rv = outStream->Write((char*)iconBuffer.Elements(), bufferCapacity,
+                          &written);
+    if (NS_SUCCEEDED(rv)) {
+      NS_IF_ADDREF(*_retval = inStream);
+    }
+  }
+
+  // Drop notification callbacks to prevent cycles.
+  mCallbacks = nullptr;
+
+  return NS_OK;
+
+  NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetLoadFlags(uint32_t* aLoadAttributes)
+{
+  return mPump->GetLoadFlags(aLoadAttributes);
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetLoadFlags(uint32_t aLoadAttributes)
+{
+  return mPump->SetLoadFlags(aLoadAttributes);
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentType(nsACString& aContentType)
+{
+  aContentType.AssignLiteral(IMAGE_ICON_MS);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentType(const nsACString& aContentType)
+{
+  //It doesn't make sense to set the content-type on this type
+  // of channel...
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentCharset(nsACString& aContentCharset)
+{
+  aContentCharset.AssignLiteral(IMAGE_ICON_MS);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentCharset(const nsACString& aContentCharset)
+{
+  //It doesn't make sense to set the content-type on this type
+  // of channel...
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentDisposition(uint32_t* aContentDisposition)
+{
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentDisposition(uint32_t aContentDisposition)
+{
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::
+  GetContentDispositionFilename(nsAString& aContentDispositionFilename)
+{
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::
+  SetContentDispositionFilename(const nsAString& aContentDispositionFilename)
+{
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::
+  GetContentDispositionHeader(nsACString& aContentDispositionHeader)
+{
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentLength(int64_t* aContentLength)
+{
+  *aContentLength = 0;
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentLength(int64_t aContentLength)
+{
+  NS_NOTREACHED("nsIconChannel::SetContentLength");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetLoadGroup(nsILoadGroup** aLoadGroup)
+{
+  *aLoadGroup = mLoadGroup;
+  NS_IF_ADDREF(*aLoadGroup);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetLoadGroup(nsILoadGroup* aLoadGroup)
+{
+  mLoadGroup = aLoadGroup;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetOwner(nsISupports** aOwner)
+{
+  *aOwner = mOwner.get();
+  NS_IF_ADDREF(*aOwner);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetOwner(nsISupports* aOwner)
+{
+  mOwner = aOwner;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetLoadInfo(nsILoadInfo** aLoadInfo)
+{
+  NS_IF_ADDREF(*aLoadInfo = mLoadInfo);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetLoadInfo(nsILoadInfo* aLoadInfo)
+{
+  mLoadInfo = aLoadInfo;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::
+  GetNotificationCallbacks(nsIInterfaceRequestor** aNotificationCallbacks)
+{
+  *aNotificationCallbacks = mCallbacks.get();
+  NS_IF_ADDREF(*aNotificationCallbacks);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::
+  SetNotificationCallbacks(nsIInterfaceRequestor* aNotificationCallbacks)
+{
+  mCallbacks = aNotificationCallbacks;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetSecurityInfo(nsISupports** aSecurityInfo)
+{
+  *aSecurityInfo = nullptr;
+  return NS_OK;
+}
+
diff --git a/image/decoders/icon/moz.build b/image/decoders/icon/moz.build
new file mode 100644
index 000000000..9c6106fa7
--- /dev/null
+++ b/image/decoders/icon/moz.build
@@ -0,0 +1,32 @@
+# -*- 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/.
+
+UNIFIED_SOURCES += [
+    'nsIconModule.cpp',
+    'nsIconProtocolHandler.cpp',
+    'nsIconURI.cpp',
+]
+
+FINAL_LIBRARY = 'xul'
+
+include('/ipc/chromium/chromium-config.mozbuild')
+
+platform = None
+
+if 'gtk' in CONFIG['MOZ_WIDGET_TOOLKIT']:
+    platform = 'gtk'
+
+if CONFIG['OS_ARCH'] == 'WINNT':
+    platform = 'win'
+
+if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa':
+    platform = 'mac'
+
+if CONFIG['OS_TARGET'] == 'Android':
+    platform = 'android'
+
+if platform:
+    LOCAL_INCLUDES += [platform]
diff --git a/image/decoders/icon/nsIconModule.cpp b/image/decoders/icon/nsIconModule.cpp
new file mode 100644
index 000000000..36225374d
--- /dev/null
+++ b/image/decoders/icon/nsIconModule.cpp
@@ -0,0 +1,60 @@
+/* -*- 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/. */
+
+#include "mozilla/ModuleUtils.h"
+#include "nsServiceManagerUtils.h"
+
+#include "nsIconProtocolHandler.h"
+#include "nsIconURI.h"
+#include "nsIconChannel.h"
+
+// objects that just require generic constructors
+//*****************************************************************************
+// Protocol CIDs
+
+#define NS_ICONPROTOCOL_CID { 0xd0f9db12, 0x249c, 0x11d5, \
+                              { 0x99, 0x5, 0x0, 0x10, 0x83, 0x1, 0xe, 0x9b } }
+
+NS_GENERIC_FACTORY_CONSTRUCTOR(nsIconProtocolHandler)
+NS_GENERIC_FACTORY_CONSTRUCTOR(nsMozIconURI)
+
+NS_DEFINE_NAMED_CID(NS_ICONPROTOCOL_CID);
+NS_DEFINE_NAMED_CID(NS_MOZICONURI_CID);
+
+static const mozilla::Module::CIDEntry kIconCIDs[] = {
+  { &kNS_ICONPROTOCOL_CID, false, nullptr, nsIconProtocolHandlerConstructor },
+  { &kNS_MOZICONURI_CID, false, nullptr, nsMozIconURIConstructor },
+  { nullptr }
+};
+
+static const mozilla::Module::ContractIDEntry kIconContracts[] = {
+  { NS_NETWORK_PROTOCOL_CONTRACTID_PREFIX "moz-icon", &kNS_ICONPROTOCOL_CID },
+  { nullptr }
+};
+
+static const mozilla::Module::CategoryEntry kIconCategories[] = {
+  { nullptr }
+};
+
+static void
+IconDecoderModuleDtor()
+{
+#if (MOZ_WIDGET_GTK == 2)
+  nsIconChannel::Shutdown();
+#endif
+}
+
+static const mozilla::Module kIconModule = {
+  mozilla::Module::kVersion,
+  kIconCIDs,
+  kIconContracts,
+  kIconCategories,
+  nullptr,
+  nullptr,
+  IconDecoderModuleDtor
+};
+
+NSMODULE_DEFN(nsIconDecoderModule) = &kIconModule;
diff --git a/image/decoders/icon/nsIconProtocolHandler.cpp b/image/decoders/icon/nsIconProtocolHandler.cpp
new file mode 100644
index 000000000..03aaa2a14
--- /dev/null
+++ b/image/decoders/icon/nsIconProtocolHandler.cpp
@@ -0,0 +1,126 @@
+/* -*- 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 "nsIconProtocolHandler.h"
+
+#include "nsIconChannel.h"
+#include "nsIconURI.h"
+#include "nsIURL.h"
+#include "nsCRT.h"
+#include "nsCOMPtr.h"
+#include "nsIComponentManager.h"
+#include "nsIServiceManager.h"
+#include "nsNetCID.h"
+
+///////////////////////////////////////////////////////////////////////////////
+
+nsIconProtocolHandler::nsIconProtocolHandler()
+{ }
+
+nsIconProtocolHandler::~nsIconProtocolHandler()
+{ }
+
+NS_IMPL_ISUPPORTS(nsIconProtocolHandler, nsIProtocolHandler,
+                  nsISupportsWeakReference)
+
+
+///////////////////////////////////////////////////////////////////////////////
+// nsIProtocolHandler methods:
+
+NS_IMETHODIMP
+nsIconProtocolHandler::GetScheme(nsACString& result)
+{
+  result = "moz-icon";
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconProtocolHandler::GetDefaultPort(int32_t* result)
+{
+  *result = 0;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconProtocolHandler::AllowPort(int32_t port,
+                                 const char* scheme,
+                                 bool* _retval)
+{
+    // don't override anything.
+    *_retval = false;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconProtocolHandler::GetProtocolFlags(uint32_t* result)
+{
+  *result = URI_NORELATIVE | URI_NOAUTH | URI_IS_UI_RESOURCE |
+            URI_IS_LOCAL_RESOURCE;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconProtocolHandler::NewURI(const nsACString& aSpec,
+                              const char* aOriginCharset, // ignored
+                              nsIURI* aBaseURI,
+                              nsIURI** result)
+{
+  nsCOMPtr<nsIMozIconURI> uri = new nsMozIconURI();
+  if (!uri) return NS_ERROR_OUT_OF_MEMORY;
+
+  nsresult rv = uri->SetSpec(aSpec);
+  if (NS_FAILED(rv)) return rv;
+
+  nsCOMPtr<nsIURL> iconURL;
+  uri->GetIconURL(getter_AddRefs(iconURL));
+  if (iconURL) {
+    uri = new nsNestedMozIconURI();
+    rv = uri->SetSpec(aSpec);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  NS_ADDREF(*result = uri);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconProtocolHandler::NewChannel2(nsIURI* url,
+                                   nsILoadInfo* aLoadInfo,
+                                   nsIChannel** result)
+{
+  NS_ENSURE_ARG_POINTER(url);
+  nsIconChannel* channel = new nsIconChannel;
+  if (!channel) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  NS_ADDREF(channel);
+
+  nsresult rv = channel->Init(url);
+  if (NS_FAILED(rv)) {
+    NS_RELEASE(channel);
+    return rv;
+  }
+
+  // set the loadInfo on the new channel
+  rv = channel->SetLoadInfo(aLoadInfo);
+  if (NS_FAILED(rv)) {
+    NS_RELEASE(channel);
+    return rv;
+  }
+
+  *result = channel;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconProtocolHandler::NewChannel(nsIURI* url, nsIChannel** result)
+{
+  return NewChannel2(url, nullptr, result);
+}
+
+////////////////////////////////////////////////////////////////////////////////
diff --git a/image/decoders/icon/nsIconProtocolHandler.h b/image/decoders/icon/nsIconProtocolHandler.h
new file mode 100644
index 000000000..9653d36f6
--- /dev/null
+++ b/image/decoders/icon/nsIconProtocolHandler.h
@@ -0,0 +1,26 @@
+/* -*- 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/. */
+
+#ifndef mozilla_image_decoders_icon_nsIconProtocolHandler_h
+#define mozilla_image_decoders_icon_nsIconProtocolHandler_h
+
+#include "nsWeakReference.h"
+#include "nsIProtocolHandler.h"
+
+class nsIconProtocolHandler : public nsIProtocolHandler,
+                              public nsSupportsWeakReference
+{
+public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIPROTOCOLHANDLER
+
+    // nsIconProtocolHandler methods:
+    nsIconProtocolHandler();
+
+protected:
+    virtual ~nsIconProtocolHandler();
+};
+
+#endif // mozilla_image_decoders_icon_nsIconProtocolHandler_h
diff --git a/image/decoders/icon/nsIconURI.cpp b/image/decoders/icon/nsIconURI.cpp
new file mode 100644
index 000000000..2c2788c8f
--- /dev/null
+++ b/image/decoders/icon/nsIconURI.cpp
@@ -0,0 +1,699 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set sw=2 sts=2 ts=2 et 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 "nsIconURI.h"
+
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/ipc/URIUtils.h"
+#include "mozilla/Sprintf.h"
+
+#include "nsIIOService.h"
+#include "nsIURL.h"
+#include "nsNetUtil.h"
+#include "plstr.h"
+#include <stdlib.h>
+
+using namespace mozilla;
+using namespace mozilla::ipc;
+
+#define DEFAULT_IMAGE_SIZE 16
+
+#if defined(MAX_PATH)
+#define SANE_FILE_NAME_LEN MAX_PATH
+#elif defined(PATH_MAX)
+#define SANE_FILE_NAME_LEN PATH_MAX
+#else
+#define SANE_FILE_NAME_LEN 1024
+#endif
+
+// helper function for parsing out attributes like size, and contentType
+// from the icon url.
+static void extractAttributeValue(const char* aSearchString,
+                                  const char* aAttributeName,
+                                  nsCString& aResult);
+
+static const char* kSizeStrings[] =
+{
+  "button",
+  "toolbar",
+  "toolbarsmall",
+  "menu",
+  "dnd",
+  "dialog"
+};
+
+static const char* kStateStrings[] =
+{
+  "normal",
+  "disabled"
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+nsMozIconURI::nsMozIconURI()
+  : mSize(DEFAULT_IMAGE_SIZE),
+    mIconSize(-1),
+    mIconState(-1)
+{ }
+
+nsMozIconURI::~nsMozIconURI()
+{ }
+
+NS_IMPL_ISUPPORTS(nsMozIconURI, nsIMozIconURI, nsIURI, nsIIPCSerializableURI)
+
+#define MOZICON_SCHEME "moz-icon:"
+#define MOZICON_SCHEME_LEN (sizeof(MOZICON_SCHEME) - 1)
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIURI methods:
+
+NS_IMETHODIMP
+nsMozIconURI::GetSpec(nsACString& aSpec)
+{
+  aSpec = MOZICON_SCHEME;
+
+  if (mIconURL) {
+    nsAutoCString fileIconSpec;
+    nsresult rv = mIconURL->GetSpec(fileIconSpec);
+    NS_ENSURE_SUCCESS(rv, rv);
+    aSpec += fileIconSpec;
+  } else if (!mStockIcon.IsEmpty()) {
+    aSpec += "//stock/";
+    aSpec += mStockIcon;
+  } else {
+    aSpec += "//";
+    aSpec += mFileName;
+  }
+
+  aSpec += "?size=";
+  if (mIconSize >= 0) {
+    aSpec += kSizeStrings[mIconSize];
+  } else {
+    char buf[20];
+    SprintfLiteral(buf, "%d", mSize);
+    aSpec.Append(buf);
+  }
+
+  if (mIconState >= 0) {
+    aSpec += "&state=";
+    aSpec += kStateStrings[mIconState];
+  }
+
+  if (!mContentType.IsEmpty()) {
+    aSpec += "&contentType=";
+    aSpec += mContentType.get();
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetSpecIgnoringRef(nsACString& result)
+{
+  return GetSpec(result);
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetHasRef(bool* result)
+{
+  *result = false;
+  return NS_OK;
+}
+
+// takes a string like ?size=32&contentType=text/html and returns a new string
+// containing just the attribute value. i.e you could pass in this string with
+// an attribute name of 'size=', this will return 32
+// Assumption: attribute pairs in the string are separated by '&'.
+void
+extractAttributeValue(const char* aSearchString,
+                           const char* aAttributeName,
+                           nsCString& aResult)
+{
+  //NS_ENSURE_ARG_POINTER(extractAttributeValue);
+
+  aResult.Truncate();
+
+  if (aSearchString && aAttributeName) {
+    // search the string for attributeName
+    uint32_t attributeNameSize = strlen(aAttributeName);
+    const char* startOfAttribute = PL_strcasestr(aSearchString, aAttributeName);
+    if (startOfAttribute &&
+       ( *(startOfAttribute-1) == '?' || *(startOfAttribute-1) == '&') ) {
+      startOfAttribute += attributeNameSize; // skip over the attributeName
+      // is there something after the attribute name
+      if (*startOfAttribute) {
+        const char* endofAttribute = strchr(startOfAttribute, '&');
+        if (endofAttribute) {
+          aResult.Assign(Substring(startOfAttribute, endofAttribute));
+        } else {
+          aResult.Assign(startOfAttribute);
+        }
+      } // if we have a attribute value
+    } // if we have a attribute name
+  } // if we got non-null search string and attribute name values
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SetSpec(const nsACString& aSpec)
+{
+  // Reset everything to default values.
+  mIconURL = nullptr;
+  mSize = DEFAULT_IMAGE_SIZE;
+  mContentType.Truncate();
+  mFileName.Truncate();
+  mStockIcon.Truncate();
+  mIconSize = -1;
+  mIconState = -1;
+
+  nsAutoCString iconSpec(aSpec);
+  if (!Substring(iconSpec, 0,
+                 MOZICON_SCHEME_LEN).EqualsLiteral(MOZICON_SCHEME)) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  int32_t questionMarkPos = iconSpec.Find("?");
+  if (questionMarkPos != -1 &&
+      static_cast<int32_t>(iconSpec.Length()) > (questionMarkPos + 1)) {
+    extractAttributeValue(iconSpec.get(), "contentType=", mContentType);
+
+    nsAutoCString sizeString;
+    extractAttributeValue(iconSpec.get(), "size=", sizeString);
+    if (!sizeString.IsEmpty()) {
+      const char* sizeStr = sizeString.get();
+      for (uint32_t i = 0; i < ArrayLength(kSizeStrings); i++) {
+        if (PL_strcasecmp(sizeStr, kSizeStrings[i]) == 0) {
+          mIconSize = i;
+          break;
+        }
+      }
+
+      int32_t sizeValue = atoi(sizeString.get());
+      if (sizeValue > 0) {
+        mSize = sizeValue;
+      }
+    }
+
+    nsAutoCString stateString;
+    extractAttributeValue(iconSpec.get(), "state=", stateString);
+    if (!stateString.IsEmpty()) {
+      const char* stateStr = stateString.get();
+      for (uint32_t i = 0; i < ArrayLength(kStateStrings); i++) {
+        if (PL_strcasecmp(stateStr, kStateStrings[i]) == 0) {
+          mIconState = i;
+          break;
+        }
+      }
+    }
+  }
+
+  int32_t pathLength = iconSpec.Length() - MOZICON_SCHEME_LEN;
+  if (questionMarkPos != -1) {
+    pathLength = questionMarkPos - MOZICON_SCHEME_LEN;
+  }
+  if (pathLength < 3) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  nsAutoCString iconPath(Substring(iconSpec, MOZICON_SCHEME_LEN, pathLength));
+
+  // Icon URI path can have three forms:
+  // (1) //stock/<icon-identifier>
+  // (2) //<some dummy file with an extension>
+  // (3) a valid URL
+
+  if (!strncmp("//stock/", iconPath.get(), 8)) {
+    mStockIcon.Assign(Substring(iconPath, 8));
+    // An icon identifier must always be specified.
+    if (mStockIcon.IsEmpty()) {
+      return NS_ERROR_MALFORMED_URI;
+    }
+    return NS_OK;
+  }
+
+  if (StringBeginsWith(iconPath, NS_LITERAL_CSTRING("//"))) {
+    // Sanity check this supposed dummy file name.
+    if (iconPath.Length() > SANE_FILE_NAME_LEN) {
+      return NS_ERROR_MALFORMED_URI;
+    }
+    iconPath.Cut(0, 2);
+    mFileName.Assign(iconPath);
+  }
+
+  nsresult rv;
+  nsCOMPtr<nsIIOService> ioService(do_GetService(NS_IOSERVICE_CONTRACTID, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIURI> uri;
+  ioService->NewURI(iconPath, nullptr, nullptr, getter_AddRefs(uri));
+  mIconURL = do_QueryInterface(uri);
+  if (mIconURL) {
+    mFileName.Truncate();
+  } else if (mFileName.IsEmpty()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetPrePath(nsACString& prePath)
+{
+  prePath = MOZICON_SCHEME;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetScheme(nsACString& aScheme)
+{
+  aScheme = "moz-icon";
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SetScheme(const nsACString& aScheme)
+{
+  // doesn't make sense to set the scheme of a moz-icon URL
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetUsername(nsACString& aUsername)
+{
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SetUsername(const nsACString& aUsername)
+{
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetPassword(nsACString& aPassword)
+{
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SetPassword(const nsACString& aPassword)
+{
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetUserPass(nsACString& aUserPass)
+{
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SetUserPass(const nsACString& aUserPass)
+{
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetHostPort(nsACString& aHostPort)
+{
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SetHostPort(const nsACString& aHostPort)
+{
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SetHostAndPort(const nsACString& aHostPort)
+{
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetHost(nsACString& aHost)
+{
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SetHost(const nsACString& aHost)
+{
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetPort(int32_t* aPort)
+{
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SetPort(int32_t aPort)
+{
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetPath(nsACString& aPath)
+{
+  aPath.Truncate();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SetPath(const nsACString& aPath)
+{
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetRef(nsACString& aRef)
+{
+  aRef.Truncate();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SetRef(const nsACString& aRef)
+{
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::Equals(nsIURI* other, bool* result)
+{
+  *result = false;
+  NS_ENSURE_ARG_POINTER(other);
+  NS_PRECONDITION(result, "null pointer");
+
+  nsAutoCString spec1;
+  nsAutoCString spec2;
+
+  nsresult rv = GetSpec(spec1);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = other->GetSpec(spec2);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (!PL_strcasecmp(spec1.get(), spec2.get())) {
+    *result = true;
+  } else {
+    *result = false;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::EqualsExceptRef(nsIURI* other, bool* result)
+{
+  // GetRef/SetRef not supported by nsMozIconURI, so
+  // EqualsExceptRef() is the same as Equals().
+  return Equals(other, result);
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SchemeIs(const char* aScheme, bool* aEquals)
+{
+  NS_ENSURE_ARG_POINTER(aEquals);
+  if (!aScheme) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  *aEquals = PL_strcasecmp("moz-icon", aScheme) ? false : true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::Clone(nsIURI** result)
+{
+  nsCOMPtr<nsIURL> newIconURL;
+  if (mIconURL) {
+    nsCOMPtr<nsIURI> newURI;
+    nsresult rv = mIconURL->Clone(getter_AddRefs(newURI));
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+    newIconURL = do_QueryInterface(newURI, &rv);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  nsMozIconURI* uri = new nsMozIconURI();
+  newIconURL.swap(uri->mIconURL);
+  uri->mSize = mSize;
+  uri->mContentType = mContentType;
+  uri->mFileName = mFileName;
+  uri->mStockIcon = mStockIcon;
+  uri->mIconSize = mIconSize;
+  uri->mIconState = mIconState;
+  NS_ADDREF(*result = uri);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::CloneIgnoringRef(nsIURI** result)
+{
+  // GetRef/SetRef not supported by nsMozIconURI, so
+  // CloneIgnoringRef() is the same as Clone().
+  return Clone(result);
+}
+
+NS_IMETHODIMP
+nsMozIconURI::CloneWithNewRef(const nsACString& newRef, nsIURI** result)
+{
+  // GetRef/SetRef not supported by nsMozIconURI, so
+  // CloneWithNewRef() is the same as Clone().
+  return Clone(result);
+}
+
+
+NS_IMETHODIMP
+nsMozIconURI::Resolve(const nsACString& relativePath, nsACString& result)
+{
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetAsciiSpec(nsACString& aSpecA)
+{
+  return GetSpec(aSpecA);
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetAsciiHostPort(nsACString& aHostPortA)
+{
+  return GetHostPort(aHostPortA);
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetAsciiHost(nsACString& aHostA)
+{
+  return GetHost(aHostA);
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetOriginCharset(nsACString& result)
+{
+  result.Truncate();
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIIconUri methods:
+
+NS_IMETHODIMP
+nsMozIconURI::GetIconURL(nsIURL** aFileUrl)
+{
+  *aFileUrl = mIconURL;
+  NS_IF_ADDREF(*aFileUrl);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SetIconURL(nsIURL* aFileUrl)
+{
+  // this isn't called anywhere, needs to go through SetSpec parsing
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetImageSize(uint32_t* aImageSize)
+              // measured by # of pixels in a row. defaults to 16.
+{
+  *aImageSize = mSize;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SetImageSize(uint32_t aImageSize)
+              // measured by # of pixels in a row. defaults to 16.
+{
+  mSize = aImageSize;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetContentType(nsACString& aContentType)
+{
+  aContentType = mContentType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SetContentType(const nsACString& aContentType)
+{
+  mContentType = aContentType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetFileExtension(nsACString& aFileExtension)
+{
+  // First, try to get the extension from mIconURL if we have one
+  if (mIconURL) {
+    nsAutoCString fileExt;
+    if (NS_SUCCEEDED(mIconURL->GetFileExtension(fileExt))) {
+      if (!fileExt.IsEmpty()) {
+        // unfortunately, this code doesn't give us the required '.' in
+        // front of the extension so we have to do it ourselves.
+        aFileExtension.Assign('.');
+        aFileExtension.Append(fileExt);
+      }
+    }
+    return NS_OK;
+  }
+
+  if (!mFileName.IsEmpty()) {
+    // truncate the extension out of the file path...
+    const char* chFileName = mFileName.get(); // get the underlying buffer
+    const char* fileExt = strrchr(chFileName, '.');
+    if (!fileExt) {
+      return NS_OK;
+    }
+    aFileExtension = fileExt;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetStockIcon(nsACString& aStockIcon)
+{
+  aStockIcon = mStockIcon;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetIconSize(nsACString& aSize)
+{
+  if (mIconSize >= 0) {
+    aSize = kSizeStrings[mIconSize];
+  } else {
+    aSize.Truncate();
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetIconState(nsACString& aState)
+{
+  if (mIconState >= 0) {
+    aState = kStateStrings[mIconState];
+  } else {
+    aState.Truncate();
+  }
+  return NS_OK;
+}
+////////////////////////////////////////////////////////////////////////////////
+// nsIIPCSerializableURI methods:
+
+void
+nsMozIconURI::Serialize(URIParams& aParams)
+{
+  IconURIParams params;
+
+  if (mIconURL) {
+    URIParams iconURLParams;
+    SerializeURI(mIconURL, iconURLParams);
+    if (iconURLParams.type() == URIParams::T__None) {
+      // Serialization failed, bail.
+      return;
+    }
+
+    params.uri() = iconURLParams;
+  } else {
+    params.uri() = void_t();
+  }
+
+  params.size() = mSize;
+  params.fileName() = mFileName;
+  params.stockIcon() = mStockIcon;
+  params.iconSize() = mIconSize;
+  params.iconState() = mIconState;
+
+  aParams = params;
+}
+
+bool
+nsMozIconURI::Deserialize(const URIParams& aParams)
+{
+  if (aParams.type() != URIParams::TIconURIParams) {
+    MOZ_ASSERT_UNREACHABLE("Received unknown URI from other process!");
+    return false;
+  }
+
+  const IconURIParams& params = aParams.get_IconURIParams();
+  if (params.uri().type() != OptionalURIParams::Tvoid_t) {
+    nsCOMPtr<nsIURI> uri = DeserializeURI(params.uri().get_URIParams());
+    mIconURL = do_QueryInterface(uri);
+    if (!mIconURL) {
+      MOZ_ASSERT_UNREACHABLE("bad nsIURI passed");
+      return false;
+    }
+  }
+
+  mSize = params.size();
+  mContentType = params.contentType();
+  mFileName = params.fileName();
+  mStockIcon = params.stockIcon();
+  mIconSize = params.iconSize();
+  mIconState = params.iconState();
+
+  return true;
+}
+
+////////////////////////////////////////////////////////////
+// Nested version of nsIconURI
+
+nsNestedMozIconURI::nsNestedMozIconURI()
+{ }
+
+nsNestedMozIconURI::~nsNestedMozIconURI()
+{ }
+
+NS_IMPL_ISUPPORTS_INHERITED(nsNestedMozIconURI, nsMozIconURI, nsINestedURI)
+
+NS_IMETHODIMP
+nsNestedMozIconURI::GetInnerURI(nsIURI** aURI)
+{
+  nsCOMPtr<nsIURI> iconURL = do_QueryInterface(mIconURL);
+  if (iconURL) {
+    iconURL.forget(aURI);
+  } else {
+    *aURI = nullptr;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsNestedMozIconURI::GetInnermostURI(nsIURI** aURI)
+{
+  return NS_ImplGetInnermostURI(this, aURI);
+}
+
diff --git a/image/decoders/icon/nsIconURI.h b/image/decoders/icon/nsIconURI.h
new file mode 100644
index 000000000..1c0310bec
--- /dev/null
+++ b/image/decoders/icon/nsIconURI.h
@@ -0,0 +1,63 @@
+/* -*- Mode: IDL; 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/. */
+
+#ifndef mozilla_image_decoders_icon_nsIconURI_h
+#define mozilla_image_decoders_icon_nsIconURI_h
+
+#include "nsIIconURI.h"
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include "nsIIPCSerializableURI.h"
+#include "nsINestedURI.h"
+
+class nsMozIconURI : public nsIMozIconURI
+                   , public nsIIPCSerializableURI
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIURI
+  NS_DECL_NSIMOZICONURI
+  NS_DECL_NSIIPCSERIALIZABLEURI
+
+  // nsMozIconURI
+  nsMozIconURI();
+
+protected:
+  virtual ~nsMozIconURI();
+  nsCOMPtr<nsIURL> mIconURL; // a URL that we want the icon for
+  uint32_t mSize; // the # of pixels in a row that we want for this image.
+                  // Typically 16, 32, 128, etc.
+  nsCString mContentType; // optional field explicitly specifying the content
+                          // type
+  nsCString mFileName; // for if we don't have an actual file path, we're just
+                       // given a filename with an extension
+  nsCString mStockIcon;
+  int32_t mIconSize;   // -1 if not specified, otherwise index into
+                       // kSizeStrings
+  int32_t mIconState;  // -1 if not specified, otherwise index into
+                       // kStateStrings
+};
+
+// For moz-icon URIs that point to an actual file on disk and are
+// therefore nested URIs
+class nsNestedMozIconURI final : public nsMozIconURI
+                               , public nsINestedURI
+{
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_FORWARD_NSIURI(nsMozIconURI::)
+  NS_FORWARD_NSIMOZICONURI(nsMozIconURI::)
+  NS_FORWARD_NSIIPCSERIALIZABLEURI(nsMozIconURI::)
+
+  NS_DECL_NSINESTEDURI
+
+  nsNestedMozIconURI();
+
+protected:
+  virtual ~nsNestedMozIconURI();
+
+};
+
+#endif // mozilla_image_decoders_icon_nsIconURI_h
diff --git a/image/decoders/icon/win/moz.build b/image/decoders/icon/win/moz.build
new file mode 100644
index 000000000..6f763d953
--- /dev/null
+++ b/image/decoders/icon/win/moz.build
@@ -0,0 +1,11 @@
+# -*- 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/.
+
+SOURCES += [
+    'nsIconChannel.cpp',
+]
+
+FINAL_LIBRARY = 'xul'
diff --git a/image/decoders/icon/win/nsIconChannel.cpp b/image/decoders/icon/win/nsIconChannel.cpp
new file mode 100644
index 000000000..9ddcbbc48
--- /dev/null
+++ b/image/decoders/icon/win/nsIconChannel.cpp
@@ -0,0 +1,841 @@
+/* -*- 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 "mozilla/ArrayUtils.h"
+
+#include "nsIconChannel.h"
+#include "nsIIconURI.h"
+#include "nsIServiceManager.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsXPIDLString.h"
+#include "nsReadableUtils.h"
+#include "nsMimeTypes.h"
+#include "nsMemory.h"
+#include "nsIStringStream.h"
+#include "nsIURL.h"
+#include "nsIOutputStream.h"
+#include "nsIPipe.h"
+#include "nsNetCID.h"
+#include "nsIFile.h"
+#include "nsIFileURL.h"
+#include "nsIMIMEService.h"
+#include "nsCExternalHandlerService.h"
+#include "nsDirectoryServiceDefs.h"
+#include "nsProxyRelease.h"
+#include "nsContentSecurityManager.h"
+#include "nsContentUtils.h"
+
+#ifdef _WIN32_WINNT
+#undef _WIN32_WINNT
+#endif
+#define _WIN32_WINNT 0x0600
+
+// we need windows.h to read out registry information...
+#include <windows.h>
+#include <shellapi.h>
+#include <shlobj.h>
+#include <objbase.h>
+#include <wchar.h>
+
+using namespace mozilla;
+
+struct ICONFILEHEADER {
+  uint16_t ifhReserved;
+  uint16_t ifhType;
+  uint16_t ifhCount;
+};
+
+struct ICONENTRY {
+  int8_t ieWidth;
+  int8_t ieHeight;
+  uint8_t ieColors;
+  uint8_t ieReserved;
+  uint16_t iePlanes;
+  uint16_t ieBitCount;
+  uint32_t ieSizeImage;
+  uint32_t ieFileOffset;
+};
+
+// Match stock icons with names
+static SHSTOCKICONID
+GetStockIconIDForName(const nsACString& aStockName)
+{
+  return aStockName.EqualsLiteral("uac-shield") ? SIID_SHIELD :
+                                                  SIID_INVALID;
+}
+
+// nsIconChannel methods
+nsIconChannel::nsIconChannel()
+{
+}
+
+nsIconChannel::~nsIconChannel()
+{
+  if (mLoadInfo) {
+    NS_ReleaseOnMainThread(mLoadInfo.forget());
+  }
+}
+
+NS_IMPL_ISUPPORTS(nsIconChannel,
+                  nsIChannel,
+                  nsIRequest,
+                  nsIRequestObserver,
+                  nsIStreamListener)
+
+nsresult
+nsIconChannel::Init(nsIURI* uri)
+{
+  NS_ASSERTION(uri, "no uri");
+  mUrl = uri;
+  mOriginalURI = uri;
+  nsresult rv;
+  mPump = do_CreateInstance(NS_INPUTSTREAMPUMP_CONTRACTID, &rv);
+  return rv;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIRequest methods:
+
+NS_IMETHODIMP
+nsIconChannel::GetName(nsACString& result)
+{
+  return mUrl->GetSpec(result);
+}
+
+NS_IMETHODIMP
+nsIconChannel::IsPending(bool* result)
+{
+  return mPump->IsPending(result);
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetStatus(nsresult* status)
+{
+  return mPump->GetStatus(status);
+}
+
+NS_IMETHODIMP
+nsIconChannel::Cancel(nsresult status)
+{
+  return mPump->Cancel(status);
+}
+
+NS_IMETHODIMP
+nsIconChannel::Suspend(void)
+{
+  return mPump->Suspend();
+}
+
+NS_IMETHODIMP
+nsIconChannel::Resume(void)
+{
+  return mPump->Resume();
+}
+NS_IMETHODIMP
+nsIconChannel::GetLoadGroup(nsILoadGroup** aLoadGroup)
+{
+  *aLoadGroup = mLoadGroup;
+  NS_IF_ADDREF(*aLoadGroup);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetLoadGroup(nsILoadGroup* aLoadGroup)
+{
+  mLoadGroup = aLoadGroup;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetLoadFlags(uint32_t* aLoadAttributes)
+{
+  return mPump->GetLoadFlags(aLoadAttributes);
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetLoadFlags(uint32_t aLoadAttributes)
+{
+  return mPump->SetLoadFlags(aLoadAttributes);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIChannel methods:
+
+NS_IMETHODIMP
+nsIconChannel::GetOriginalURI(nsIURI** aURI)
+{
+  *aURI = mOriginalURI;
+  NS_ADDREF(*aURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetOriginalURI(nsIURI* aURI)
+{
+  NS_ENSURE_ARG_POINTER(aURI);
+  mOriginalURI = aURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetURI(nsIURI** aURI)
+{
+  *aURI = mUrl;
+  NS_IF_ADDREF(*aURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::Open(nsIInputStream** _retval)
+{
+  return MakeInputStream(_retval, false);
+}
+
+NS_IMETHODIMP
+nsIconChannel::Open2(nsIInputStream** aStream)
+{
+  nsCOMPtr<nsIStreamListener> listener;
+  nsresult rv = nsContentSecurityManager::doContentSecurityCheck(this, listener);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return Open(aStream);
+}
+
+nsresult
+nsIconChannel::ExtractIconInfoFromUrl(nsIFile** aLocalFile,
+                        uint32_t* aDesiredImageSize, nsCString& aContentType,
+                        nsCString& aFileExtension)
+{
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIMozIconURI> iconURI (do_QueryInterface(mUrl, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  iconURI->GetImageSize(aDesiredImageSize);
+  iconURI->GetContentType(aContentType);
+  iconURI->GetFileExtension(aFileExtension);
+
+  nsCOMPtr<nsIURL> url;
+  rv = iconURI->GetIconURL(getter_AddRefs(url));
+  if (NS_FAILED(rv) || !url) return NS_OK;
+
+  nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(url, &rv);
+  if (NS_FAILED(rv) || !fileURL) return NS_OK;
+
+  nsCOMPtr<nsIFile> file;
+  rv = fileURL->GetFile(getter_AddRefs(file));
+  if (NS_FAILED(rv) || !file) return NS_OK;
+
+  return file->Clone(aLocalFile);
+}
+
+NS_IMETHODIMP
+nsIconChannel::AsyncOpen(nsIStreamListener* aListener,
+                                       nsISupports* ctxt)
+{
+  MOZ_ASSERT(!mLoadInfo ||
+             mLoadInfo->GetSecurityMode() == 0 ||
+             mLoadInfo->GetInitialSecurityCheckDone() ||
+             (mLoadInfo->GetSecurityMode() == nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_DATA_IS_NULL &&
+              nsContentUtils::IsSystemPrincipal(mLoadInfo->LoadingPrincipal())),
+             "security flags in loadInfo but asyncOpen2() not called");
+
+  nsCOMPtr<nsIInputStream> inStream;
+  nsresult rv = MakeInputStream(getter_AddRefs(inStream), true);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // Init our streampump
+  rv = mPump->Init(inStream, int64_t(-1), int64_t(-1), 0, 0, false);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = mPump->AsyncRead(this, ctxt);
+  if (NS_SUCCEEDED(rv)) {
+    // Store our real listener
+    mListener = aListener;
+    // Add ourself to the load group, if available
+    if (mLoadGroup) {
+      mLoadGroup->AddRequest(this, nullptr);
+    }
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+nsIconChannel::AsyncOpen2(nsIStreamListener* aListener)
+{
+  nsCOMPtr<nsIStreamListener> listener = aListener;
+  nsresult rv = nsContentSecurityManager::doContentSecurityCheck(this, listener);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return AsyncOpen(listener, nullptr);
+}
+
+static DWORD
+GetSpecialFolderIcon(nsIFile* aFile, int aFolder,
+                                  SHFILEINFOW* aSFI, UINT aInfoFlags)
+{
+  DWORD shellResult = 0;
+
+  if (!aFile) {
+    return shellResult;
+  }
+
+  wchar_t fileNativePath[MAX_PATH];
+  nsAutoString fileNativePathStr;
+  aFile->GetPath(fileNativePathStr);
+  ::GetShortPathNameW(fileNativePathStr.get(), fileNativePath,
+                      ArrayLength(fileNativePath));
+
+  LPITEMIDLIST idList;
+  HRESULT hr = ::SHGetSpecialFolderLocation(nullptr, aFolder, &idList);
+  if (SUCCEEDED(hr)) {
+    wchar_t specialNativePath[MAX_PATH];
+    ::SHGetPathFromIDListW(idList, specialNativePath);
+    ::GetShortPathNameW(specialNativePath, specialNativePath,
+                        ArrayLength(specialNativePath));
+
+    if (!wcsicmp(fileNativePath, specialNativePath)) {
+      aInfoFlags |= (SHGFI_PIDL | SHGFI_SYSICONINDEX);
+      shellResult = ::SHGetFileInfoW((LPCWSTR)(LPCITEMIDLIST)idList, 0,
+                                      aSFI,
+                                     sizeof(*aSFI), aInfoFlags);
+    }
+  }
+  CoTaskMemFree(idList);
+  return shellResult;
+}
+
+static UINT
+GetSizeInfoFlag(uint32_t aDesiredImageSize)
+{
+  return
+    (UINT) (aDesiredImageSize > 16 ? SHGFI_SHELLICONSIZE : SHGFI_SMALLICON);
+}
+
+nsresult
+nsIconChannel::GetHIconFromFile(HICON* hIcon)
+{
+  nsXPIDLCString contentType;
+  nsCString fileExt;
+  nsCOMPtr<nsIFile> localFile; // file we want an icon for
+  uint32_t desiredImageSize;
+  nsresult rv = ExtractIconInfoFromUrl(getter_AddRefs(localFile),
+                                       &desiredImageSize, contentType,
+                                       fileExt);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // if the file exists, we are going to use it's real attributes...
+  // otherwise we only want to use it for it's extension...
+  SHFILEINFOW      sfi;
+  UINT infoFlags = SHGFI_ICON;
+
+  bool fileExists = false;
+
+  nsAutoString filePath;
+  CopyASCIItoUTF16(fileExt, filePath);
+  if (localFile) {
+    rv = localFile->Normalize();
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    localFile->GetPath(filePath);
+    if (filePath.Length() < 2 || filePath[1] != ':') {
+      return NS_ERROR_MALFORMED_URI; // UNC
+    }
+
+    if (filePath.Last() == ':') {
+      filePath.Append('\\');
+    } else {
+      localFile->Exists(&fileExists);
+      if (!fileExists) {
+       localFile->GetLeafName(filePath);
+      }
+    }
+  }
+
+  if (!fileExists) {
+   infoFlags |= SHGFI_USEFILEATTRIBUTES;
+  }
+
+  infoFlags |= GetSizeInfoFlag(desiredImageSize);
+
+  // if we have a content type... then use it! but for existing files,
+  // we want to show their real icon.
+  if (!fileExists && !contentType.IsEmpty()) {
+    nsCOMPtr<nsIMIMEService> mimeService
+      (do_GetService(NS_MIMESERVICE_CONTRACTID, &rv));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsAutoCString defFileExt;
+    mimeService->GetPrimaryExtension(contentType, fileExt, defFileExt);
+    // If the mime service does not know about this mime type, we show
+    // the generic icon.
+    // In any case, we need to insert a '.' before the extension.
+    filePath = NS_LITERAL_STRING(".") +
+               NS_ConvertUTF8toUTF16(defFileExt);
+  }
+
+  // Is this the "Desktop" folder?
+  DWORD shellResult = GetSpecialFolderIcon(localFile, CSIDL_DESKTOP,
+                                           &sfi, infoFlags);
+  if (!shellResult) {
+    // Is this the "My Documents" folder?
+    shellResult = GetSpecialFolderIcon(localFile, CSIDL_PERSONAL,
+                                       &sfi, infoFlags);
+  }
+
+  // There are other "Special Folders" and Namespace entities that we
+  // are not fetching icons for, see:
+  // http://msdn.microsoft.com/library/default.asp?url=/library/en-us/
+  //        shellcc/platform/shell/reference/enums/csidl.asp
+  // If we ever need to get them, code to do so would be inserted here.
+
+  // Not a special folder, or something else failed above.
+  if (!shellResult) {
+    shellResult = ::SHGetFileInfoW(filePath.get(),
+                                   FILE_ATTRIBUTE_ARCHIVE,
+                                   &sfi, sizeof(sfi), infoFlags);
+  }
+
+  if (shellResult && sfi.hIcon) {
+    *hIcon = sfi.hIcon;
+  } else {
+    rv = NS_ERROR_NOT_AVAILABLE;
+  }
+
+  return rv;
+}
+
+nsresult
+nsIconChannel::GetStockHIcon(nsIMozIconURI* aIconURI,
+                                      HICON* hIcon)
+{
+  nsresult rv = NS_OK;
+
+  // We can only do this on Vista or above
+  HMODULE hShellDLL = ::LoadLibraryW(L"shell32.dll");
+  decltype(SHGetStockIconInfo)* pSHGetStockIconInfo =
+    (decltype(SHGetStockIconInfo)*) ::GetProcAddress(hShellDLL,
+                                                    "SHGetStockIconInfo");
+
+  if (pSHGetStockIconInfo) {
+    uint32_t desiredImageSize;
+    aIconURI->GetImageSize(&desiredImageSize);
+    nsAutoCString stockIcon;
+    aIconURI->GetStockIcon(stockIcon);
+
+    SHSTOCKICONID stockIconID = GetStockIconIDForName(stockIcon);
+    if (stockIconID == SIID_INVALID) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+
+    UINT infoFlags = SHGSI_ICON;
+    infoFlags |= GetSizeInfoFlag(desiredImageSize);
+
+    SHSTOCKICONINFO sii = {0};
+    sii.cbSize = sizeof(sii);
+    HRESULT hr = pSHGetStockIconInfo(stockIconID, infoFlags, &sii);
+
+    if (SUCCEEDED(hr)) {
+      *hIcon = sii.hIcon;
+    } else {
+      rv = NS_ERROR_FAILURE;
+    }
+  } else {
+    rv = NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (hShellDLL) {
+    ::FreeLibrary(hShellDLL);
+  }
+
+  return rv;
+}
+
+// Given a BITMAPINFOHEADER, returns the size of the color table.
+static int
+GetColorTableSize(BITMAPINFOHEADER* aHeader)
+{
+  int colorTableSize = -1;
+
+  // http://msdn.microsoft.com/en-us/library/dd183376%28v=VS.85%29.aspx
+  switch (aHeader->biBitCount) {
+  case 0:
+    colorTableSize = 0;
+    break;
+  case 1:
+    colorTableSize = 2 * sizeof(RGBQUAD);
+    break;
+  case 4:
+  case 8: {
+    // The maximum possible size for the color table is 2**bpp, so check for
+    // that and fail if we're not in those bounds
+    unsigned int maxEntries = 1 << (aHeader->biBitCount);
+    if (aHeader->biClrUsed > 0 && aHeader->biClrUsed <= maxEntries) {
+      colorTableSize = aHeader->biClrUsed * sizeof(RGBQUAD);
+    } else if (aHeader->biClrUsed == 0) {
+      colorTableSize = maxEntries * sizeof(RGBQUAD);
+    }
+    break;
+  }
+  case 16:
+  case 32:
+    // If we have BI_BITFIELDS compression, we would normally need 3 DWORDS for
+    // the bitfields mask which would be stored in the color table; However,
+    // we instead force the bitmap to request data of type BI_RGB so the color
+    // table should be of size 0.
+    // Setting aHeader->biCompression = BI_RGB forces the later call to
+    // GetDIBits to return to us BI_RGB data.
+    if (aHeader->biCompression == BI_BITFIELDS) {
+      aHeader->biCompression = BI_RGB;
+    }
+    colorTableSize = 0;
+    break;
+  case 24:
+    colorTableSize = 0;
+    break;
+  }
+
+  if (colorTableSize < 0) {
+    NS_WARNING("Unable to figure out the color table size for this bitmap");
+  }
+
+  return colorTableSize;
+}
+
+// Given a header and a size, creates a freshly allocated BITMAPINFO structure.
+// It is the caller's responsibility to null-check and delete the structure.
+static BITMAPINFO*
+CreateBitmapInfo(BITMAPINFOHEADER* aHeader, size_t aColorTableSize)
+{
+  BITMAPINFO* bmi = (BITMAPINFO*) ::operator new(sizeof(BITMAPINFOHEADER) +
+                                                 aColorTableSize,
+                                                 mozilla::fallible);
+  if (bmi) {
+    memcpy(bmi, aHeader, sizeof(BITMAPINFOHEADER));
+    memset(bmi->bmiColors, 0, aColorTableSize);
+  }
+  return bmi;
+}
+
+nsresult
+nsIconChannel::MakeInputStream(nsIInputStream** _retval, bool aNonBlocking)
+{
+  // Check whether the icon requested's a file icon or a stock icon
+  nsresult rv = NS_ERROR_NOT_AVAILABLE;
+
+  // GetDIBits does not exist on windows mobile.
+  HICON hIcon = nullptr;
+
+  nsCOMPtr<nsIMozIconURI> iconURI(do_QueryInterface(mUrl, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString stockIcon;
+  iconURI->GetStockIcon(stockIcon);
+  if (!stockIcon.IsEmpty()) {
+    rv = GetStockHIcon(iconURI, &hIcon);
+  } else {
+    rv = GetHIconFromFile(&hIcon);
+  }
+
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (hIcon) {
+    // we got a handle to an icon. Now we want to get a bitmap for the icon
+    // using GetIconInfo....
+    ICONINFO iconInfo;
+    if (GetIconInfo(hIcon, &iconInfo)) {
+      // we got the bitmaps, first find out their size
+      HDC hDC = CreateCompatibleDC(nullptr); // get a device context for
+                                             // the screen.
+      BITMAPINFOHEADER maskHeader  = {sizeof(BITMAPINFOHEADER)};
+      BITMAPINFOHEADER colorHeader = {sizeof(BITMAPINFOHEADER)};
+      int colorTableSize, maskTableSize;
+      if (GetDIBits(hDC, iconInfo.hbmMask,  0, 0, nullptr,
+                    (BITMAPINFO*)&maskHeader,  DIB_RGB_COLORS) &&
+          GetDIBits(hDC, iconInfo.hbmColor, 0, 0, nullptr,
+                    (BITMAPINFO*)&colorHeader, DIB_RGB_COLORS) &&
+          maskHeader.biHeight == colorHeader.biHeight &&
+          maskHeader.biWidth  == colorHeader.biWidth  &&
+          colorHeader.biBitCount > 8 &&
+          colorHeader.biSizeImage > 0 &&
+          colorHeader.biWidth >= 0 && colorHeader.biWidth <= 255 &&
+          colorHeader.biHeight >= 0 && colorHeader.biHeight <= 255 &&
+          maskHeader.biSizeImage > 0  &&
+          (colorTableSize = GetColorTableSize(&colorHeader)) >= 0 &&
+          (maskTableSize  = GetColorTableSize(&maskHeader))  >= 0) {
+        uint32_t iconSize = sizeof(ICONFILEHEADER) +
+                            sizeof(ICONENTRY) +
+                            sizeof(BITMAPINFOHEADER) +
+                            colorHeader.biSizeImage +
+                            maskHeader.biSizeImage;
+
+        UniquePtr<char[]> buffer = MakeUnique<char[]>(iconSize);
+        if (!buffer) {
+          rv = NS_ERROR_OUT_OF_MEMORY;
+        } else {
+          char* whereTo = buffer.get();
+          int howMuch;
+
+          // the data starts with an icon file header
+          ICONFILEHEADER iconHeader;
+          iconHeader.ifhReserved = 0;
+          iconHeader.ifhType = 1;
+          iconHeader.ifhCount = 1;
+          howMuch = sizeof(ICONFILEHEADER);
+          memcpy(whereTo, &iconHeader, howMuch);
+          whereTo += howMuch;
+
+          // followed by the single icon entry
+          ICONENTRY iconEntry;
+          iconEntry.ieWidth = static_cast<int8_t>(colorHeader.biWidth);
+          iconEntry.ieHeight = static_cast<int8_t>(colorHeader.biHeight);
+          iconEntry.ieColors = 0;
+          iconEntry.ieReserved = 0;
+          iconEntry.iePlanes = 1;
+          iconEntry.ieBitCount = colorHeader.biBitCount;
+          iconEntry.ieSizeImage = sizeof(BITMAPINFOHEADER) +
+                                  colorHeader.biSizeImage +
+                                  maskHeader.biSizeImage;
+          iconEntry.ieFileOffset = sizeof(ICONFILEHEADER) + sizeof(ICONENTRY);
+          howMuch = sizeof(ICONENTRY);
+          memcpy(whereTo, &iconEntry, howMuch);
+          whereTo += howMuch;
+
+          // followed by the bitmap info header
+          // (doubling the height because icons have two bitmaps)
+          colorHeader.biHeight *= 2;
+          colorHeader.biSizeImage += maskHeader.biSizeImage;
+          howMuch = sizeof(BITMAPINFOHEADER);
+          memcpy(whereTo, &colorHeader, howMuch);
+          whereTo += howMuch;
+          colorHeader.biHeight /= 2;
+          colorHeader.biSizeImage -= maskHeader.biSizeImage;
+
+          // followed by the XOR bitmap data (colorHeader)
+          // (you'd expect the color table to come here, but it apparently
+          // doesn't)
+          BITMAPINFO* colorInfo = CreateBitmapInfo(&colorHeader,
+                                                   colorTableSize);
+          if (colorInfo && GetDIBits(hDC, iconInfo.hbmColor, 0,
+                                     colorHeader.biHeight, whereTo, colorInfo,
+                                     DIB_RGB_COLORS)) {
+            whereTo += colorHeader.biSizeImage;
+
+            // and finally the AND bitmap data (maskHeader)
+            BITMAPINFO* maskInfo = CreateBitmapInfo(&maskHeader, maskTableSize);
+            if (maskInfo && GetDIBits(hDC, iconInfo.hbmMask, 0,
+                                      maskHeader.biHeight, whereTo, maskInfo,
+                                      DIB_RGB_COLORS)) {
+              // Now, create a pipe and stuff our data into it
+              nsCOMPtr<nsIInputStream> inStream;
+              nsCOMPtr<nsIOutputStream> outStream;
+              rv = NS_NewPipe(getter_AddRefs(inStream),
+                              getter_AddRefs(outStream),
+                              iconSize, iconSize, aNonBlocking);
+              if (NS_SUCCEEDED(rv)) {
+                uint32_t written;
+                rv = outStream->Write(buffer.get(), iconSize, &written);
+                if (NS_SUCCEEDED(rv)) {
+                  NS_ADDREF(*_retval = inStream);
+                }
+              }
+
+            } // if we got bitmap bits
+            delete maskInfo;
+          } // if we got mask bits
+          delete colorInfo;
+        } // if we allocated the buffer
+      } // if we got mask size
+
+      DeleteDC(hDC);
+      DeleteObject(iconInfo.hbmColor);
+      DeleteObject(iconInfo.hbmMask);
+    } // if we got icon info
+    DestroyIcon(hIcon);
+  } // if we got an hIcon
+
+  // If we didn't make a stream, then fail.
+  if (!*_retval && NS_SUCCEEDED(rv)) {
+    rv = NS_ERROR_NOT_AVAILABLE;
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentType(nsACString& aContentType)
+{
+  aContentType.AssignLiteral(IMAGE_ICO);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentType(const nsACString& aContentType)
+{
+  // It doesn't make sense to set the content-type on this type
+  // of channel...
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP nsIconChannel::GetContentCharset(nsACString& aContentCharset)
+{
+  aContentCharset.Truncate();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentCharset(const nsACString& aContentCharset)
+{
+  // It doesn't make sense to set the content-charset on this type
+  // of channel...
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentDisposition(uint32_t* aContentDisposition)
+{
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentDisposition(uint32_t aContentDisposition)
+{
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::
+  GetContentDispositionFilename(nsAString& aContentDispositionFilename)
+{
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::
+  SetContentDispositionFilename(const nsAString& aContentDispositionFilename)
+{
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::
+  GetContentDispositionHeader(nsACString& aContentDispositionHeader)
+{
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentLength(int64_t* aContentLength)
+{
+  *aContentLength = 0;
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentLength(int64_t aContentLength)
+{
+  NS_NOTREACHED("nsIconChannel::SetContentLength");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetOwner(nsISupports** aOwner)
+{
+  *aOwner = mOwner.get();
+  NS_IF_ADDREF(*aOwner);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetOwner(nsISupports* aOwner)
+{
+  mOwner = aOwner;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetLoadInfo(nsILoadInfo** aLoadInfo)
+{
+  NS_IF_ADDREF(*aLoadInfo = mLoadInfo);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetLoadInfo(nsILoadInfo* aLoadInfo)
+{
+  mLoadInfo = aLoadInfo;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::
+  GetNotificationCallbacks(nsIInterfaceRequestor** aNotificationCallbacks)
+{
+  *aNotificationCallbacks = mCallbacks.get();
+  NS_IF_ADDREF(*aNotificationCallbacks);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::
+  SetNotificationCallbacks(nsIInterfaceRequestor* aNotificationCallbacks)
+{
+  mCallbacks = aNotificationCallbacks;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetSecurityInfo(nsISupports** aSecurityInfo)
+{
+  *aSecurityInfo = nullptr;
+  return NS_OK;
+}
+
+// nsIRequestObserver methods
+NS_IMETHODIMP nsIconChannel::OnStartRequest(nsIRequest* aRequest,
+                                            nsISupports* aContext)
+{
+  if (mListener) {
+    return mListener->OnStartRequest(this, aContext);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::OnStopRequest(nsIRequest* aRequest,
+                             nsISupports* aContext,
+                             nsresult aStatus)
+{
+  if (mListener) {
+    mListener->OnStopRequest(this, aContext, aStatus);
+    mListener = nullptr;
+  }
+
+  // Remove from load group
+  if (mLoadGroup) {
+    mLoadGroup->RemoveRequest(this, nullptr, aStatus);
+  }
+
+  // Drop notification callbacks to prevent cycles.
+  mCallbacks = nullptr;
+
+  return NS_OK;
+}
+
+// nsIStreamListener methods
+NS_IMETHODIMP
+nsIconChannel::OnDataAvailable(nsIRequest* aRequest,
+                               nsISupports* aContext,
+                               nsIInputStream* aStream,
+                               uint64_t aOffset,
+                               uint32_t aCount)
+{
+  if (mListener) {
+    return mListener->OnDataAvailable(this, aContext, aStream, aOffset, aCount);
+  }
+  return NS_OK;
+}
diff --git a/image/decoders/icon/win/nsIconChannel.h b/image/decoders/icon/win/nsIconChannel.h
new file mode 100644
index 000000000..94df5a52e
--- /dev/null
+++ b/image/decoders/icon/win/nsIconChannel.h
@@ -0,0 +1,66 @@
+/* -*- 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/. */
+
+#ifndef mozilla_image_encoders_icon_win_nsIconChannel_h
+#define mozilla_image_encoders_icon_win_nsIconChannel_h
+
+#include "mozilla/Attributes.h"
+
+#include "nsCOMPtr.h"
+#include "nsXPIDLString.h"
+#include "nsIChannel.h"
+#include "nsILoadGroup.h"
+#include "nsILoadInfo.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsIURI.h"
+#include "nsIInputStreamPump.h"
+#include "nsIStreamListener.h"
+#include "nsIIconURI.h"
+
+#include <windows.h>
+
+class nsIFile;
+
+class nsIconChannel final : public nsIChannel, public nsIStreamListener
+{
+  ~nsIconChannel();
+
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIREQUEST
+  NS_DECL_NSICHANNEL
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+
+  nsIconChannel();
+
+  nsresult Init(nsIURI* uri);
+
+protected:
+  nsCOMPtr<nsIURI> mUrl;
+  nsCOMPtr<nsIURI> mOriginalURI;
+  nsCOMPtr<nsILoadGroup> mLoadGroup;
+  nsCOMPtr<nsIInterfaceRequestor> mCallbacks;
+  nsCOMPtr<nsISupports>  mOwner;
+  nsCOMPtr<nsILoadInfo>  mLoadInfo;
+
+  nsCOMPtr<nsIInputStreamPump> mPump;
+  nsCOMPtr<nsIStreamListener>  mListener;
+
+  nsresult ExtractIconInfoFromUrl(nsIFile** aLocalFile,
+                                  uint32_t* aDesiredImageSize,
+                                  nsCString& aContentType,
+                                  nsCString& aFileExtension);
+  nsresult GetHIconFromFile(HICON* hIcon);
+  nsresult MakeInputStream(nsIInputStream** _retval, bool nonBlocking);
+
+  // Functions specific to Vista and above
+protected:
+  nsresult GetStockHIcon(nsIMozIconURI* aIconURI, HICON* hIcon);
+};
+
+#endif // mozilla_image_encoders_icon_win_nsIconChannel_h