Merge branch 'master' into js-modules

# Conflicts:
#	modules/libpref/init/all.js

15 files changed, 167 insertions, 723 deletions

diff --git a/js/xpconnect/src/Sandbox.cpp b/js/xpconnect/src/Sandbox.cpp
index 120772ed2..a516cf73f 100644
--- a/js/xpconnect/src/Sandbox.cpp
+++ b/js/xpconnect/src/Sandbox.cpp
@@ -66,7 +66,6 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(SandboxPrivate)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(SandboxPrivate)
-  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
   tmp->TraverseHostObjectURIs(cb);
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
diff --git a/js/xpconnect/src/XPCComponents.cpp b/js/xpconnect/src/XPCComponents.cpp
index dbb63092e..07ce7460b 100644
--- a/js/xpconnect/src/XPCComponents.cpp
+++ b/js/xpconnect/src/XPCComponents.cpp
@@ -34,9 +34,11 @@
 #include "nsDOMClassInfo.h"
 #include "ShimInterfaceInfo.h"
 #include "nsIAddonInterposition.h"
+#include "nsIScriptError.h"
 #include "nsISimpleEnumerator.h"
 #include "nsPIDOMWindow.h"
 #include "nsGlobalWindow.h"
+#include "nsScriptError.h"
 
 using namespace mozilla;
 using namespace JS;
diff --git a/js/xpconnect/src/XPCConvert.cpp b/js/xpconnect/src/XPCConvert.cpp
index 37932b452..77f09f4a5 100644
--- a/js/xpconnect/src/XPCConvert.cpp
+++ b/js/xpconnect/src/XPCConvert.cpp
@@ -11,9 +11,11 @@
 
 #include "xpcprivate.h"
 #include "nsIAtom.h"
+#include "nsIScriptError.h"
 #include "nsWrapperCache.h"
 #include "nsJSUtils.h"
 #include "nsQueryObject.h"
+#include "nsScriptError.h"
 #include "WrapperFactory.h"
 
 #include "nsWrapperCacheInlines.h"
diff --git a/js/xpconnect/src/XPCJSContext.cpp b/js/xpconnect/src/XPCJSContext.cpp
index f352607d4..0243d80e3 100644
--- a/js/xpconnect/src/XPCJSContext.cpp
+++ b/js/xpconnect/src/XPCJSContext.cpp
@@ -28,7 +28,6 @@
 #include "nsPIDOMWindow.h"
 #include "nsPrintfCString.h"
 #include "mozilla/Preferences.h"
-#include "mozilla/Telemetry.h"
 #include "mozilla/Services.h"
 #include "mozilla/dom/ScriptSettings.h"
 
@@ -133,10 +132,7 @@ class AsyncFreeSnowWhite : public Runnable
 public:
   NS_IMETHOD Run() override
   {
-      TimeStamp start = TimeStamp::Now();
       bool hadSnowWhiteObjects = nsCycleCollector_doDeferredDeletion();
-      Telemetry::Accumulate(Telemetry::CYCLE_COLLECTOR_ASYNC_SNOW_WHITE_FREEING,
-                            uint32_t((TimeStamp::Now() - start).ToMilliseconds()));
       if (hadSnowWhiteObjects && !mContinuation) {
           mContinuation = true;
           if (NS_FAILED(NS_DispatchToCurrentThread(this))) {
@@ -1238,8 +1234,6 @@ XPCJSContext::InterruptCallback(JSContext* cx)
     if (self->mSlowScriptCheckpoint.IsNull()) {
         self->mSlowScriptCheckpoint = TimeStamp::NowLoRes();
         self->mSlowScriptSecondHalf = false;
-        self->mSlowScriptActualWait = mozilla::TimeDuration();
-        self->mTimeoutAccumulated = false;
         return true;
     }
 
@@ -1261,8 +1255,6 @@ XPCJSContext::InterruptCallback(JSContext* cx)
     if (limit == 0 || duration.ToSeconds() < limit / 2.0)
         return true;
 
-    self->mSlowScriptActualWait += duration;
-
     // In order to guard against time changes or laptops going to sleep, we
     // don't trigger the slow script warning until (limit/2) seconds have
     // elapsed twice.
@@ -1314,13 +1306,6 @@ XPCJSContext::InterruptCallback(JSContext* cx)
         return false;
     }
 
-    // Accumulate slow script invokation delay.
-    if (!chrome && !self->mTimeoutAccumulated) {
-      uint32_t delay = uint32_t(self->mSlowScriptActualWait.ToMilliseconds() - (limit * 1000.0));
-      Telemetry::Accumulate(Telemetry::SLOW_SCRIPT_NOTIFY_DELAY, delay);
-      self->mTimeoutAccumulated = true;
-    }
-
     // Show the prompt to the user, and kill if requested.
     nsGlobalWindow::SlowScriptResponse response = win->ShowSlowScriptDialog();
     if (response == nsGlobalWindow::KillSlowScript) {
@@ -2953,105 +2938,6 @@ JSSizeOfTab(JSObject* objArg, size_t* jsObjectsSize, size_t* jsStringsSize,
 } // namespace xpc
 
 static void
-AccumulateTelemetryCallback(int id, uint32_t sample, const char* key)
-{
-    switch (id) {
-      case JS_TELEMETRY_GC_REASON:
-        Telemetry::Accumulate(Telemetry::GC_REASON_2, sample);
-        break;
-      case JS_TELEMETRY_GC_IS_ZONE_GC:
-        Telemetry::Accumulate(Telemetry::GC_IS_COMPARTMENTAL, sample);
-        break;
-      case JS_TELEMETRY_GC_MS:
-        Telemetry::Accumulate(Telemetry::GC_MS, sample);
-        break;
-      case JS_TELEMETRY_GC_BUDGET_MS:
-        Telemetry::Accumulate(Telemetry::GC_BUDGET_MS, sample);
-        break;
-      case JS_TELEMETRY_GC_ANIMATION_MS:
-        Telemetry::Accumulate(Telemetry::GC_ANIMATION_MS, sample);
-        break;
-      case JS_TELEMETRY_GC_MAX_PAUSE_MS:
-        Telemetry::Accumulate(Telemetry::GC_MAX_PAUSE_MS, sample);
-        break;
-      case JS_TELEMETRY_GC_MARK_MS:
-        Telemetry::Accumulate(Telemetry::GC_MARK_MS, sample);
-        break;
-      case JS_TELEMETRY_GC_SWEEP_MS:
-        Telemetry::Accumulate(Telemetry::GC_SWEEP_MS, sample);
-        break;
-      case JS_TELEMETRY_GC_COMPACT_MS:
-        Telemetry::Accumulate(Telemetry::GC_COMPACT_MS, sample);
-        break;
-      case JS_TELEMETRY_GC_MARK_ROOTS_MS:
-        Telemetry::Accumulate(Telemetry::GC_MARK_ROOTS_MS, sample);
-        break;
-      case JS_TELEMETRY_GC_MARK_GRAY_MS:
-        Telemetry::Accumulate(Telemetry::GC_MARK_GRAY_MS, sample);
-        break;
-      case JS_TELEMETRY_GC_SLICE_MS:
-        Telemetry::Accumulate(Telemetry::GC_SLICE_MS, sample);
-        break;
-      case JS_TELEMETRY_GC_SLOW_PHASE:
-        Telemetry::Accumulate(Telemetry::GC_SLOW_PHASE, sample);
-        break;
-      case JS_TELEMETRY_GC_MMU_50:
-        Telemetry::Accumulate(Telemetry::GC_MMU_50, sample);
-        break;
-      case JS_TELEMETRY_GC_RESET:
-        Telemetry::Accumulate(Telemetry::GC_RESET, sample);
-        break;
-      case JS_TELEMETRY_GC_RESET_REASON:
-        Telemetry::Accumulate(Telemetry::GC_RESET_REASON, sample);
-        break;
-      case JS_TELEMETRY_GC_INCREMENTAL_DISABLED:
-        Telemetry::Accumulate(Telemetry::GC_INCREMENTAL_DISABLED, sample);
-        break;
-      case JS_TELEMETRY_GC_NON_INCREMENTAL:
-        Telemetry::Accumulate(Telemetry::GC_NON_INCREMENTAL, sample);
-        break;
-      case JS_TELEMETRY_GC_NON_INCREMENTAL_REASON:
-        Telemetry::Accumulate(Telemetry::GC_NON_INCREMENTAL_REASON, sample);
-        break;
-      case JS_TELEMETRY_GC_SCC_SWEEP_TOTAL_MS:
-        Telemetry::Accumulate(Telemetry::GC_SCC_SWEEP_TOTAL_MS, sample);
-        break;
-      case JS_TELEMETRY_GC_SCC_SWEEP_MAX_PAUSE_MS:
-        Telemetry::Accumulate(Telemetry::GC_SCC_SWEEP_MAX_PAUSE_MS, sample);
-        break;
-      case JS_TELEMETRY_GC_MINOR_REASON:
-        Telemetry::Accumulate(Telemetry::GC_MINOR_REASON, sample);
-        break;
-      case JS_TELEMETRY_GC_MINOR_REASON_LONG:
-        Telemetry::Accumulate(Telemetry::GC_MINOR_REASON_LONG, sample);
-        break;
-      case JS_TELEMETRY_GC_MINOR_US:
-        Telemetry::Accumulate(Telemetry::GC_MINOR_US, sample);
-        break;
-      case JS_TELEMETRY_GC_NURSERY_BYTES:
-        Telemetry::Accumulate(Telemetry::GC_NURSERY_BYTES, sample);
-        break;
-      case JS_TELEMETRY_GC_PRETENURE_COUNT:
-        Telemetry::Accumulate(Telemetry::GC_PRETENURE_COUNT, sample);
-        break;
-      case JS_TELEMETRY_DEPRECATED_LANGUAGE_EXTENSIONS_IN_CONTENT:
-        Telemetry::Accumulate(Telemetry::JS_DEPRECATED_LANGUAGE_EXTENSIONS_IN_CONTENT, sample);
-        break;
-      case JS_TELEMETRY_DEPRECATED_LANGUAGE_EXTENSIONS_IN_ADDONS:
-        Telemetry::Accumulate(Telemetry::JS_DEPRECATED_LANGUAGE_EXTENSIONS_IN_ADDONS, sample);
-        break;
-      case JS_TELEMETRY_ADDON_EXCEPTIONS:
-        Telemetry::Accumulate(Telemetry::JS_TELEMETRY_ADDON_EXCEPTIONS, nsDependentCString(key), sample);
-        break;
-      case JS_TELEMETRY_AOT_USAGE:
-        Telemetry::Accumulate(Telemetry::JS_AOT_USAGE, sample);
-        break;
-      default:
-        MOZ_ASSERT_UNREACHABLE("Unexpected JS_TELEMETRY id");
-    }
-}
-
-static void
 CompartmentNameCallback(JSContext* cx, JSCompartment* comp,
                         char* buf, size_t bufsize)
 {
@@ -3210,7 +3096,6 @@ XPCJSContext::XPCJSContext()
    mWatchdogManager(new WatchdogManager(this)),
    mAsyncSnowWhiteFreer(new AsyncFreeSnowWhite()),
    mSlowScriptSecondHalf(false),
-   mTimeoutAccumulated(false),
    mPendingResult(NS_OK)
 {
 }
@@ -3376,7 +3261,6 @@ XPCJSContext::Initialize()
     JS_AddWeakPointerCompartmentCallback(cx, WeakPointerCompartmentCallback, this);
     JS_SetWrapObjectCallbacks(cx, &WrapObjectCallbacks);
     js::SetPreserveWrapperCallback(cx, PreserveWrapper);
-    JS_SetAccumulateTelemetryCallback(cx, AccumulateTelemetryCallback);
     js::SetActivityCallback(cx, ActivityCallback, this);
     JS_AddInterruptCallback(cx, InterruptCallback);
     js::SetWindowProxyClass(cx, &OuterWindowProxyClass);
@@ -3541,8 +3425,6 @@ XPCJSContext::BeforeProcessTask(bool aMightBlock)
     // Start the slow script timer.
     mSlowScriptCheckpoint = mozilla::TimeStamp::NowLoRes();
     mSlowScriptSecondHalf = false;
-    mSlowScriptActualWait = mozilla::TimeDuration();
-    mTimeoutAccumulated = false;
 
     // As we may be entering a nested event loop, we need to
     // cancel any ongoing performance measurement.
diff --git a/js/xpconnect/src/XPCModule.h b/js/xpconnect/src/XPCModule.h
index d62764625..506e8945a 100644
--- a/js/xpconnect/src/XPCModule.h
+++ b/js/xpconnect/src/XPCModule.h
@@ -23,7 +23,6 @@
 NS_GENERIC_FACTORY_CONSTRUCTOR(nsJSID)
 NS_GENERIC_FACTORY_SINGLETON_CONSTRUCTOR(nsIXPConnect,
                                          nsXPConnect::GetSingleton)
-NS_GENERIC_FACTORY_CONSTRUCTOR(nsScriptError)
 
 NS_GENERIC_FACTORY_CONSTRUCTOR(mozJSComponentLoader)
 NS_GENERIC_FACTORY_CONSTRUCTOR(mozJSSubScriptLoader)
@@ -31,14 +30,12 @@ NS_GENERIC_FACTORY_CONSTRUCTOR(mozJSSubScriptLoader)
 NS_DEFINE_NAMED_CID(NS_JS_ID_CID);
 NS_DEFINE_NAMED_CID(NS_XPCONNECT_CID);
 NS_DEFINE_NAMED_CID(NS_XPCEXCEPTION_CID);
-NS_DEFINE_NAMED_CID(NS_SCRIPTERROR_CID);
 NS_DEFINE_NAMED_CID(MOZJSCOMPONENTLOADER_CID);
 NS_DEFINE_NAMED_CID(MOZ_JSSUBSCRIPTLOADER_CID);
 
 #define XPCONNECT_CIDENTRIES                                                  \
   { &kNS_JS_ID_CID, false, nullptr,  nsJSIDConstructor },                     \
   { &kNS_XPCONNECT_CID, false, nullptr,  nsIXPConnectConstructor },           \
-  { &kNS_SCRIPTERROR_CID, false, nullptr, nsScriptErrorConstructor },         \
   { &kMOZJSCOMPONENTLOADER_CID, false, nullptr, mozJSComponentLoaderConstructor },\
   { &kMOZ_JSSUBSCRIPTLOADER_CID, false, nullptr, mozJSSubScriptLoaderConstructor },
 
@@ -46,7 +43,6 @@ NS_DEFINE_NAMED_CID(MOZ_JSSUBSCRIPTLOADER_CID);
   { XPC_ID_CONTRACTID, &kNS_JS_ID_CID },                                      \
   { XPC_XPCONNECT_CONTRACTID, &kNS_XPCONNECT_CID },                           \
   { XPC_CONTEXT_STACK_CONTRACTID, &kNS_XPCONNECT_CID },                       \
-  { NS_SCRIPTERROR_CONTRACTID, &kNS_SCRIPTERROR_CID },                        \
   { MOZJSCOMPONENTLOADER_CONTRACTID, &kMOZJSCOMPONENTLOADER_CID },            \
   { MOZJSSUBSCRIPTLOADER_CONTRACTID, &kMOZ_JSSUBSCRIPTLOADER_CID },
 
diff --git a/js/xpconnect/src/XPCShellImpl.cpp b/js/xpconnect/src/XPCShellImpl.cpp
index a6432856d..abe50f449 100644
--- a/js/xpconnect/src/XPCShellImpl.cpp
+++ b/js/xpconnect/src/XPCShellImpl.cpp
@@ -644,7 +644,7 @@ env_setProperty(JSContext* cx, HandleObject obj, HandleId id, MutableHandleValue
                 ObjectOpResult& result)
 {
 /* XXX porting may be easy, but these don't seem to supply setenv by default */
-#if !defined SOLARIS
+#if !defined XP_SOLARIS	
     RootedString valstr(cx);
     RootedString idstr(cx);
     int rv;
@@ -663,7 +663,7 @@ env_setProperty(JSContext* cx, HandleObject obj, HandleId id, MutableHandleValue
     JSAutoByteString value(cx, valstr);
     if (!value)
         return false;
-#if defined XP_WIN || defined HPUX || defined OSF1 || defined SCO
+#if defined XP_WIN || defined SCO
     {
         char* waste = JS_smprintf("%s=%s", name.ptr(), value.ptr());
         if (!waste) {
@@ -671,16 +671,7 @@ env_setProperty(JSContext* cx, HandleObject obj, HandleId id, MutableHandleValue
             return false;
         }
         rv = putenv(waste);
-#ifdef XP_WIN
-        /*
-         * HPUX9 at least still has the bad old non-copying putenv.
-         *
-         * Per mail from <s.shanmuganathan@digital.com>, OSF1 also has a putenv
-         * that will crash if you pass it an auto char array (so it must place
-         * its argument directly in the char* environ[] array).
-         */
         free(waste);
-#endif
     }
 #else
     rv = setenv(name.ptr(), value.ptr(), 1);
@@ -696,7 +687,7 @@ env_setProperty(JSContext* cx, HandleObject obj, HandleId id, MutableHandleValue
         return false;
     }
     vp.setString(valstr);
-#endif /* !defined SOLARIS */
+#endif /* !defined XP_SOLARIS */    
     return result.succeed();
 }
 
diff --git a/js/xpconnect/src/XPCWrappedJSClass.cpp b/js/xpconnect/src/XPCWrappedJSClass.cpp
index 2c9fd66bc..e90373e3d 100644
--- a/js/xpconnect/src/XPCWrappedJSClass.cpp
+++ b/js/xpconnect/src/XPCWrappedJSClass.cpp
@@ -10,6 +10,7 @@
 #include "jsprf.h"
 #include "nsArrayEnumerator.h"
 #include "nsContentUtils.h"
+#include "nsIScriptError.h"
 #include "nsWrapperCache.h"
 #include "AccessCheck.h"
 #include "nsJSUtils.h"
diff --git a/js/xpconnect/src/XPCWrappedNativeInfo.cpp b/js/xpconnect/src/XPCWrappedNativeInfo.cpp
index 302454fb5..4b0330af6 100644
--- a/js/xpconnect/src/XPCWrappedNativeInfo.cpp
+++ b/js/xpconnect/src/XPCWrappedNativeInfo.cpp
@@ -11,6 +11,7 @@
 
 #include "mozilla/MemoryReporting.h"
 #include "mozilla/XPTInterfaceInfoManager.h"
+#include "nsIScriptError.h"
 #include "nsPrintfCString.h"
 
 using namespace JS;
diff --git a/js/xpconnect/src/XPCWrappedNativeJSOps.cpp b/js/xpconnect/src/XPCWrappedNativeJSOps.cpp
index 12b203b70..08ba8241a 100644
--- a/js/xpconnect/src/XPCWrappedNativeJSOps.cpp
+++ b/js/xpconnect/src/XPCWrappedNativeJSOps.cpp
@@ -924,8 +924,6 @@ const js::ObjectOps XPC_WN_ObjectOpsWithEnumerate = {
     nullptr,  // setProperty
     nullptr,  // getOwnPropertyDescriptor
     nullptr,  // deleteProperty
-    nullptr,  // watch
-    nullptr,  // unwatch
     nullptr,  // getElements
     XPC_WN_JSOp_Enumerate,
     nullptr,  // funToString
diff --git a/js/xpconnect/src/moz.build b/js/xpconnect/src/moz.build
index 7e787bb56..29cfc4776 100644
--- a/js/xpconnect/src/moz.build
+++ b/js/xpconnect/src/moz.build
@@ -14,8 +14,6 @@ EXPORTS += [
 
 UNIFIED_SOURCES += [
     'ExportHelpers.cpp',
-    'nsScriptError.cpp',
-    'nsScriptErrorWithStack.cpp',
     'nsXPConnect.cpp',
     'Sandbox.cpp',
     'XPCCallContext.cpp',
@@ -58,6 +56,7 @@ LOCAL_INCLUDES += [
     '../wrappers',
     '/caps',
     '/dom/base',
+    '/dom/bindings',
     '/dom/html',
     '/dom/svg',
     '/dom/workers',
@@ -67,4 +66,4 @@ LOCAL_INCLUDES += [
 ]
 
 if CONFIG['GNU_CXX']:
-    CXXFLAGS += ['-Wno-shadow', '-Werror=format']
+    CXXFLAGS += ['-Wno-shadow']
diff --git a/js/xpconnect/src/nsScriptError.cpp b/js/xpconnect/src/nsScriptError.cpp
deleted file mode 100644
index ff687bc44..000000000
--- a/js/xpconnect/src/nsScriptError.cpp
+++ /dev/null
@@ -1,345 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
-/* vim: set ts=8 sts=4 et sw=4 tw=99: */
-/* 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/. */
-
-/*
- * nsIScriptError implementation.  Defined here, lacking a JS-specific
- * place to put XPCOM things.
- */
-
-#include "xpcprivate.h"
-#include "jsprf.h"
-#include "MainThreadUtils.h"
-#include "mozilla/Assertions.h"
-#include "nsGlobalWindow.h"
-#include "nsPIDOMWindow.h"
-#include "nsILoadContext.h"
-#include "nsIDocShell.h"
-#include "nsIScriptError.h"
-#include "nsISensitiveInfoHiddenURI.h"
-
-static_assert(nsIScriptError::errorFlag == JSREPORT_ERROR &&
-              nsIScriptError::warningFlag == JSREPORT_WARNING &&
-              nsIScriptError::exceptionFlag == JSREPORT_EXCEPTION &&
-              nsIScriptError::strictFlag == JSREPORT_STRICT &&
-              nsIScriptError::infoFlag == JSREPORT_USER_1,
-              "flags should be consistent");
-
-nsScriptErrorBase::nsScriptErrorBase()
-    :  mMessage(),
-       mMessageName(),
-       mSourceName(),
-       mLineNumber(0),
-       mSourceLine(),
-       mColumnNumber(0),
-       mFlags(0),
-       mCategory(),
-       mOuterWindowID(0),
-       mInnerWindowID(0),
-       mTimeStamp(0),
-       mInitializedOnMainThread(false),
-       mIsFromPrivateWindow(false)
-{
-}
-
-nsScriptErrorBase::~nsScriptErrorBase() {}
-
-void
-nsScriptErrorBase::InitializeOnMainThread()
-{
-    MOZ_ASSERT(NS_IsMainThread());
-    MOZ_ASSERT(!mInitializedOnMainThread);
-
-    if (mInnerWindowID) {
-        nsGlobalWindow* window =
-          nsGlobalWindow::GetInnerWindowWithId(mInnerWindowID);
-        if (window) {
-            nsPIDOMWindowOuter* outer = window->GetOuterWindow();
-            if (outer)
-                mOuterWindowID = outer->WindowID();
-
-            nsIDocShell* docShell = window->GetDocShell();
-            nsCOMPtr<nsILoadContext> loadContext = do_QueryInterface(docShell);
-
-            if (loadContext) {
-                // Never mark exceptions from chrome windows as having come from
-                // private windows, since we always want them to be reported.
-                nsIPrincipal* winPrincipal = window->GetPrincipal();
-                mIsFromPrivateWindow = loadContext->UsePrivateBrowsing() &&
-                                       !nsContentUtils::IsSystemPrincipal(winPrincipal);
-            }
-        }
-    }
-
-    mInitializedOnMainThread = true;
-}
-
-// nsIConsoleMessage methods
-NS_IMETHODIMP
-nsScriptErrorBase::GetMessageMoz(char16_t** result) {
-    nsresult rv;
-
-    nsAutoCString message;
-    rv = ToString(message);
-    if (NS_FAILED(rv))
-        return rv;
-
-    *result = UTF8ToNewUnicode(message);
-    if (!*result)
-        return NS_ERROR_OUT_OF_MEMORY;
-
-    return NS_OK;
-}
-
-
-NS_IMETHODIMP
-nsScriptErrorBase::GetLogLevel(uint32_t* aLogLevel)
-{
-  if (mFlags & (uint32_t)nsIScriptError::infoFlag) {
-    *aLogLevel = nsIConsoleMessage::info;
-  } else if (mFlags & (uint32_t)nsIScriptError::warningFlag) {
-    *aLogLevel = nsIConsoleMessage::warn;
-  } else {
-    *aLogLevel = nsIConsoleMessage::error;
-  }
-  return NS_OK;
-}
-
-// nsIScriptError methods
-NS_IMETHODIMP
-nsScriptErrorBase::GetErrorMessage(nsAString& aResult) {
-    aResult.Assign(mMessage);
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::GetSourceName(nsAString& aResult) {
-    aResult.Assign(mSourceName);
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::GetSourceLine(nsAString& aResult) {
-    aResult.Assign(mSourceLine);
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::GetLineNumber(uint32_t* result) {
-    *result = mLineNumber;
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::GetColumnNumber(uint32_t* result) {
-    *result = mColumnNumber;
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::GetFlags(uint32_t* result) {
-    *result = mFlags;
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::GetCategory(char** result) {
-    *result = ToNewCString(mCategory);
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::GetStack(JS::MutableHandleValue aStack) {
-    aStack.setUndefined();
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::SetStack(JS::HandleValue aStack) {
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::GetErrorMessageName(nsAString& aErrorMessageName) {
-    aErrorMessageName = mMessageName;
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::SetErrorMessageName(const nsAString& aErrorMessageName) {
-    mMessageName = aErrorMessageName;
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::Init(const nsAString& message,
-                        const nsAString& sourceName,
-                        const nsAString& sourceLine,
-                        uint32_t lineNumber,
-                        uint32_t columnNumber,
-                        uint32_t flags,
-                        const char* category)
-{
-    return InitWithWindowID(message, sourceName, sourceLine, lineNumber,
-                            columnNumber, flags,
-                            category ? nsDependentCString(category)
-                                     : EmptyCString(),
-                            0);
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::InitWithWindowID(const nsAString& message,
-                                    const nsAString& sourceName,
-                                    const nsAString& sourceLine,
-                                    uint32_t lineNumber,
-                                    uint32_t columnNumber,
-                                    uint32_t flags,
-                                    const nsACString& category,
-                                    uint64_t aInnerWindowID)
-{
-    mMessage.Assign(message);
-
-    if (!sourceName.IsEmpty()) {
-        mSourceName.Assign(sourceName);
-
-        nsCOMPtr<nsIURI> uri;
-        nsAutoCString pass;
-        if (NS_SUCCEEDED(NS_NewURI(getter_AddRefs(uri), sourceName)) &&
-            NS_SUCCEEDED(uri->GetPassword(pass)) &&
-            !pass.IsEmpty()) {
-            nsCOMPtr<nsISensitiveInfoHiddenURI> safeUri =
-                do_QueryInterface(uri);
-
-            nsAutoCString loc;
-            if (safeUri &&
-                NS_SUCCEEDED(safeUri->GetSensitiveInfoHiddenSpec(loc))) {
-                mSourceName.Assign(NS_ConvertUTF8toUTF16(loc));
-            }
-        }
-    }
-
-    mLineNumber = lineNumber;
-    mSourceLine.Assign(sourceLine);
-    mColumnNumber = columnNumber;
-    mFlags = flags;
-    mCategory = category;
-    mTimeStamp = JS_Now() / 1000;
-    mInnerWindowID = aInnerWindowID;
-
-    if (aInnerWindowID && NS_IsMainThread()) {
-        InitializeOnMainThread();
-    }
-
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::ToString(nsACString& /*UTF8*/ aResult)
-{
-    static const char format0[] =
-        "[%s: \"%s\" {file: \"%s\" line: %d column: %d source: \"%s\"}]";
-    static const char format1[] =
-        "[%s: \"%s\" {file: \"%s\" line: %d}]";
-    static const char format2[] =
-        "[%s: \"%s\"]";
-
-    static const char error[]   = "JavaScript Error";
-    static const char warning[] = "JavaScript Warning";
-
-    const char* severity = !(mFlags & JSREPORT_WARNING) ? error : warning;
-
-    char* temp;
-    char* tempMessage = nullptr;
-    char* tempSourceName = nullptr;
-    char* tempSourceLine = nullptr;
-
-    if (!mMessage.IsEmpty())
-        tempMessage = ToNewUTF8String(mMessage);
-    if (!mSourceName.IsEmpty())
-        // Use at most 512 characters from mSourceName.
-        tempSourceName = ToNewUTF8String(StringHead(mSourceName, 512));
-    if (!mSourceLine.IsEmpty())
-        // Use at most 512 characters from mSourceLine.
-        tempSourceLine = ToNewUTF8String(StringHead(mSourceLine, 512));
-
-    if (nullptr != tempSourceName && nullptr != tempSourceLine)
-        temp = JS_smprintf(format0,
-                           severity,
-                           tempMessage,
-                           tempSourceName,
-                           mLineNumber,
-                           mColumnNumber,
-                           tempSourceLine);
-    else if (!mSourceName.IsEmpty())
-        temp = JS_smprintf(format1,
-                           severity,
-                           tempMessage,
-                           tempSourceName,
-                           mLineNumber);
-    else
-        temp = JS_smprintf(format2,
-                           severity,
-                           tempMessage);
-
-    if (nullptr != tempMessage)
-        free(tempMessage);
-    if (nullptr != tempSourceName)
-        free(tempSourceName);
-    if (nullptr != tempSourceLine)
-        free(tempSourceLine);
-
-    if (!temp)
-        return NS_ERROR_OUT_OF_MEMORY;
-
-    aResult.Assign(temp);
-    JS_smprintf_free(temp);
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::GetOuterWindowID(uint64_t* aOuterWindowID)
-{
-    NS_WARNING_ASSERTION(NS_IsMainThread() || mInitializedOnMainThread,
-                         "This can't be safely determined off the main thread, "
-                         "returning an inaccurate value!");
-
-    if (!mInitializedOnMainThread && NS_IsMainThread()) {
-        InitializeOnMainThread();
-    }
-
-    *aOuterWindowID = mOuterWindowID;
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::GetInnerWindowID(uint64_t* aInnerWindowID)
-{
-    *aInnerWindowID = mInnerWindowID;
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::GetTimeStamp(int64_t* aTimeStamp)
-{
-    *aTimeStamp = mTimeStamp;
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorBase::GetIsFromPrivateWindow(bool* aIsFromPrivateWindow)
-{
-    NS_WARNING_ASSERTION(NS_IsMainThread() || mInitializedOnMainThread,
-                         "This can't be safely determined off the main thread, "
-                         "returning an inaccurate value!");
-
-    if (!mInitializedOnMainThread && NS_IsMainThread()) {
-        InitializeOnMainThread();
-    }
-
-    *aIsFromPrivateWindow = mIsFromPrivateWindow;
-    return NS_OK;
-}
-
-NS_IMPL_ISUPPORTS(nsScriptError, nsIConsoleMessage, nsIScriptError)
diff --git a/js/xpconnect/src/nsScriptErrorWithStack.cpp b/js/xpconnect/src/nsScriptErrorWithStack.cpp
deleted file mode 100644
index edc12fa76..000000000
--- a/js/xpconnect/src/nsScriptErrorWithStack.cpp
+++ /dev/null
@@ -1,119 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
-/* vim: set ts=8 sts=4 et sw=4 tw=99: */
-/* 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/. */
-
-/*
- * nsScriptErrorWithStack implementation.
- * a main-thread-only, cycle-collected subclass of nsScriptErrorBase
- * that can store a SavedFrame stack trace object.
- */
-
-#include "xpcprivate.h"
-#include "MainThreadUtils.h"
-#include "mozilla/Assertions.h"
-#include "nsGlobalWindow.h"
-#include "nsCycleCollectionParticipant.h"
-
-
-namespace {
-
-static nsCString
-FormatStackString(JSContext* cx, HandleObject aStack) {
-    JS::RootedString formattedStack(cx);
-
-    if (!JS::BuildStackString(cx, aStack, &formattedStack)) {
-        return nsCString();
-    }
-
-    nsAutoJSString stackJSString;
-    if (!stackJSString.init(cx, formattedStack)) {
-        return nsCString();
-    }
-
-    return NS_ConvertUTF16toUTF8(stackJSString.get());
-}
-
-}
-
-
-NS_IMPL_CYCLE_COLLECTION_CLASS(nsScriptErrorWithStack)
-
-NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsScriptErrorWithStack)
-  tmp->mStack = nullptr;
-NS_IMPL_CYCLE_COLLECTION_UNLINK_END
-
-NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsScriptErrorWithStack)
-  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
-NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
-
-NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(nsScriptErrorWithStack)
-  NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mStack)
-NS_IMPL_CYCLE_COLLECTION_TRACE_END
-
-NS_IMPL_CYCLE_COLLECTING_ADDREF(nsScriptErrorWithStack)
-NS_IMPL_CYCLE_COLLECTING_RELEASE(nsScriptErrorWithStack)
-
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsScriptErrorWithStack)
-  NS_INTERFACE_MAP_ENTRY(nsISupports)
-  NS_INTERFACE_MAP_ENTRY(nsIConsoleMessage)
-  NS_INTERFACE_MAP_ENTRY(nsIScriptError)
-NS_INTERFACE_MAP_END
-
-nsScriptErrorWithStack::nsScriptErrorWithStack(JS::HandleObject aStack)
-  : mStack(aStack)
-{
-    MOZ_ASSERT(NS_IsMainThread(), "You can't use this class on workers.");
-    mozilla::HoldJSObjects(this);
-}
-
-nsScriptErrorWithStack::~nsScriptErrorWithStack() {
-    mozilla::DropJSObjects(this);
-}
-
-NS_IMETHODIMP
-nsScriptErrorWithStack::Init(const nsAString& message,
-                             const nsAString& sourceName,
-                             const nsAString& sourceLine,
-                             uint32_t lineNumber,
-                             uint32_t columnNumber,
-                             uint32_t flags,
-                             const char* category)
-{
-  MOZ_CRASH("nsScriptErrorWithStack requires to be initialized with a document, by using InitWithWindowID");
-}
-
-NS_IMETHODIMP
-nsScriptErrorWithStack::GetStack(JS::MutableHandleValue aStack) {
-    aStack.setObjectOrNull(mStack);
-    return NS_OK;
-}
-
-NS_IMETHODIMP
-nsScriptErrorWithStack::ToString(nsACString& /*UTF8*/ aResult)
-{
-    MOZ_ASSERT(NS_IsMainThread());
-
-    nsCString message;
-    nsresult rv = nsScriptErrorBase::ToString(message);
-    NS_ENSURE_SUCCESS(rv, rv);
-
-    if (!mStack) {
-        aResult.Assign(message);
-        return NS_OK;
-    }
-
-    AutoJSAPI jsapi;
-    if (!jsapi.Init(mStack)) {
-        return NS_ERROR_FAILURE;
-    }
-
-    JSContext* cx = jsapi.cx();
-    RootedObject stack(cx, mStack);
-    nsCString stackString = FormatStackString(cx, stack);
-    nsCString combined = message + NS_LITERAL_CSTRING("\n") + stackString;
-    aResult.Assign(combined);
-
-    return NS_OK;
-}
diff --git a/js/xpconnect/src/nsXPConnect.cpp b/js/xpconnect/src/nsXPConnect.cpp
index 0466175b1..0d1a6be0a 100644
--- a/js/xpconnect/src/nsXPConnect.cpp
+++ b/js/xpconnect/src/nsXPConnect.cpp
@@ -33,7 +33,9 @@
 #include "nsIObjectOutputStream.h"
 #include "nsScriptSecurityManager.h"
 #include "nsIPermissionManager.h"
+#include "nsIScriptError.h"
 #include "nsContentUtils.h"
+#include "nsScriptError.h"
 #include "jsfriendapi.h"
 
 using namespace mozilla;
@@ -170,9 +172,31 @@ nsXPConnect::IsISupportsDescendant(nsIInterfaceInfo* info)
 }
 
 void
+xpc::ErrorBase::Init(JSErrorBase* aReport)
+{
+    if (!aReport->filename) {
+        mFileName.SetIsVoid(true);
+    } else {
+        mFileName.AssignWithConversion(aReport->filename);
+    }
+
+    mLineNumber = aReport->lineno;
+    mColumn = aReport->column;
+}
+
+void
+xpc::ErrorNote::Init(JSErrorNotes::Note* aNote)
+{
+    xpc::ErrorBase::Init(aNote);
+
+    ErrorNoteToMessageString(aNote, mErrorMsg);
+}
+
+void
 xpc::ErrorReport::Init(JSErrorReport* aReport, const char* aToStringResult,
                        bool aIsChrome, uint64_t aWindowID)
 {
+    xpc::ErrorBase::Init(aReport);
     mCategory = aIsChrome ? NS_LITERAL_CSTRING("chrome javascript")
                           : NS_LITERAL_CSTRING("content javascript");
     mWindowID = aWindowID;
@@ -182,12 +206,6 @@ xpc::ErrorReport::Init(JSErrorReport* aReport, const char* aToStringResult,
         AppendUTF8toUTF16(aToStringResult, mErrorMsg);
     }
 
-    if (!aReport->filename) {
-        mFileName.SetIsVoid(true);
-    } else {
-        mFileName.AssignWithConversion(aReport->filename);
-    }
-
     mSourceLine.Assign(aReport->linebuf(), aReport->linebufLength());
     const JSErrorFormatString* efs = js::GetErrorMessage(nullptr, aReport->errorNumber);
 
@@ -197,10 +215,20 @@ xpc::ErrorReport::Init(JSErrorReport* aReport, const char* aToStringResult,
         mErrorMsgName.AssignASCII(efs->name);
     }
 
-    mLineNumber = aReport->lineno;
-    mColumn = aReport->column;
     mFlags = aReport->flags;
     mIsMuted = aReport->isMuted;
+
+    if (aReport->notes) {
+        if (!mNotes.SetLength(aReport->notes->length(), fallible)) {
+            return;
+        }
+
+        size_t i = 0;
+        for (auto&& note : *aReport->notes) {
+            mNotes.ElementAt(i).Init(note.get());
+            i++;
+        }
+    }
 }
 
 void
@@ -226,6 +254,59 @@ xpc::ErrorReport::Init(JSContext* aCx, mozilla::dom::Exception* aException,
 static LazyLogModule gJSDiagnostics("JSDiagnostics");
 
 void
+xpc::ErrorBase::AppendErrorDetailsTo(nsCString& error)
+{
+    error.Append(NS_LossyConvertUTF16toASCII(mFileName));
+    error.AppendLiteral(", line ");
+    error.AppendInt(mLineNumber, 10);
+    error.AppendLiteral(": ");
+    error.Append(NS_LossyConvertUTF16toASCII(mErrorMsg));
+}
+
+void
+xpc::ErrorNote::LogToStderr()
+{
+    if (!nsContentUtils::DOMWindowDumpEnabled()) {
+        return;
+    }
+
+    nsAutoCString error;
+    error.AssignLiteral("JavaScript note: ");
+    AppendErrorDetailsTo(error);
+
+    fprintf(stderr, "%s\n", error.get());
+    fflush(stderr);
+}
+
+void
+xpc::ErrorReport::LogToStderr()
+{
+    if (!nsContentUtils::DOMWindowDumpEnabled()) {
+        return;
+    }
+
+    nsAutoCString error;
+    error.AssignLiteral("JavaScript ");
+    if (JSREPORT_IS_STRICT(mFlags)) {
+        error.AppendLiteral("strict ");
+    }
+    if (JSREPORT_IS_WARNING(mFlags)) {
+        error.AppendLiteral("warning: ");
+    } else {
+        error.AppendLiteral("error: ");
+    }
+    AppendErrorDetailsTo(error);
+
+    fprintf(stderr, "%s\n", error.get());
+    fflush(stderr);
+
+    for (size_t i = 0, len = mNotes.Length(); i < len; i++) {
+        ErrorNote& note = mNotes[i];
+        note.LogToStderr();
+    }
+}
+
+void
 xpc::ErrorReport::LogToConsole()
 {
   LogToConsoleWithStack(nullptr);
@@ -233,25 +314,7 @@ xpc::ErrorReport::LogToConsole()
 void
 xpc::ErrorReport::LogToConsoleWithStack(JS::HandleObject aStack)
 {
-    // Log to stdout.
-    if (nsContentUtils::DOMWindowDumpEnabled()) {
-        nsAutoCString error;
-        error.AssignLiteral("JavaScript ");
-        if (JSREPORT_IS_STRICT(mFlags))
-            error.AppendLiteral("strict ");
-        if (JSREPORT_IS_WARNING(mFlags))
-            error.AppendLiteral("warning: ");
-        else
-            error.AppendLiteral("error: ");
-        error.Append(NS_LossyConvertUTF16toASCII(mFileName));
-        error.AppendLiteral(", line ");
-        error.AppendInt(mLineNumber, 10);
-        error.AppendLiteral(": ");
-        error.Append(NS_LossyConvertUTF16toASCII(mErrorMsg));
-
-        fprintf(stderr, "%s\n", error.get());
-        fflush(stderr);
-    }
+    LogToStderr();
 
     MOZ_LOG(gJSDiagnostics,
             JSREPORT_IS_WARNING(mFlags) ? LogLevel::Warning : LogLevel::Error,
@@ -263,8 +326,9 @@ xpc::ErrorReport::LogToConsoleWithStack(JS::HandleObject aStack)
     // mechanisms.
     nsCOMPtr<nsIConsoleService> consoleService =
       do_GetService(NS_CONSOLESERVICE_CONTRACTID);
+    NS_ENSURE_TRUE_VOID(consoleService);
 
-    nsCOMPtr<nsIScriptError> errorObject;
+    RefPtr<nsScriptErrorBase> errorObject;
     if (mWindowID && aStack) {
       // Only set stack on messages related to a document
       // As we cache messages in the console service,
@@ -275,18 +339,38 @@ xpc::ErrorReport::LogToConsoleWithStack(JS::HandleObject aStack)
       errorObject = new nsScriptError();
     }
     errorObject->SetErrorMessageName(mErrorMsgName);
-    NS_ENSURE_TRUE_VOID(consoleService);
 
     nsresult rv = errorObject->InitWithWindowID(mErrorMsg, mFileName, mSourceLine,
                                                 mLineNumber, mColumn, mFlags,
                                                 mCategory, mWindowID);
     NS_ENSURE_SUCCESS_VOID(rv);
+
+    for (size_t i = 0, len = mNotes.Length(); i < len; i++) {
+        ErrorNote& note = mNotes[i];
+
+        nsScriptErrorNote* noteObject = new nsScriptErrorNote();
+        noteObject->Init(note.mErrorMsg, note.mFileName,
+                         note.mLineNumber, note.mColumn);
+        errorObject->AddNote(noteObject);
+    }
+
     consoleService->LogMessage(errorObject);
 
 }
 
 /* static */
 void
+xpc::ErrorNote::ErrorNoteToMessageString(JSErrorNotes::Note* aNote,
+                                         nsAString& aString)
+{
+    aString.Truncate();
+    if (aNote->message()) {
+        aString.Append(NS_ConvertUTF8toUTF16(aNote->message().c_str()));
+    }
+}
+
+/* static */
+void
 xpc::ErrorReport::ErrorReportToMessageString(JSErrorReport* aReport,
                                              nsAString& aString)
 {
diff --git a/js/xpconnect/src/xpcprivate.h b/js/xpconnect/src/xpcprivate.h
index d7d5586b8..e55cc06e0 100644
--- a/js/xpconnect/src/xpcprivate.h
+++ b/js/xpconnect/src/xpcprivate.h
@@ -128,7 +128,6 @@
 #include "MainThreadUtils.h"
 
 #include "nsIConsoleService.h"
-#include "nsIScriptError.h"
 #include "nsIException.h"
 
 #include "nsVariant.h"
@@ -634,9 +633,6 @@ private:
     // (whichever comes later). We use it to determine whether the interrupt
     // callback needs to do anything.
     mozilla::TimeStamp mSlowScriptCheckpoint;
-    // Accumulates total time we actually waited for telemetry
-    mozilla::TimeDuration mSlowScriptActualWait;
-    bool mTimeoutAccumulated;
 
     // mPendingResult is used to implement Components.returnCode.  Only really
     // meaningful while calling through XPCWrappedJS.
@@ -2555,77 +2551,6 @@ extern char*
 xpc_PrintJSStack(JSContext* cx, bool showArgs, bool showLocals,
                  bool showThisProps);
 
-/***************************************************************************/
-
-// Definition of nsScriptError, defined here because we lack a place to put
-// XPCOM objects associated with the JavaScript engine.
-class nsScriptErrorBase : public nsIScriptError {
-public:
-    nsScriptErrorBase();
-
-  // TODO - do something reasonable on getting null from these babies.
-
-    NS_DECL_NSICONSOLEMESSAGE
-    NS_DECL_NSISCRIPTERROR
-
-protected:
-    virtual ~nsScriptErrorBase();
-
-    void
-    InitializeOnMainThread();
-
-    nsString mMessage;
-    nsString mMessageName;
-    nsString mSourceName;
-    uint32_t mLineNumber;
-    nsString mSourceLine;
-    uint32_t mColumnNumber;
-    uint32_t mFlags;
-    nsCString mCategory;
-    // mOuterWindowID is set on the main thread from InitializeOnMainThread().
-    uint64_t mOuterWindowID;
-    uint64_t mInnerWindowID;
-    int64_t mTimeStamp;
-    // mInitializedOnMainThread and mIsFromPrivateWindow are set on the main
-    // thread from InitializeOnMainThread().
-    mozilla::Atomic<bool> mInitializedOnMainThread;
-    bool mIsFromPrivateWindow;
-};
-
-class nsScriptError final : public nsScriptErrorBase {
-public:
-    nsScriptError() {}
-    NS_DECL_THREADSAFE_ISUPPORTS
-
-private:
-    virtual ~nsScriptError() {}
-};
-
-class nsScriptErrorWithStack : public nsScriptErrorBase {
-public:
-    explicit nsScriptErrorWithStack(JS::HandleObject);
-
-    NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-    NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(nsScriptErrorWithStack)
-
-    NS_IMETHOD Init(const nsAString& message,
-                    const nsAString& sourceName,
-                    const nsAString& sourceLine,
-                    uint32_t lineNumber,
-                    uint32_t columnNumber,
-                    uint32_t flags,
-                    const char* category) override;
-
-    NS_IMETHOD GetStack(JS::MutableHandleValue) override;
-    NS_IMETHOD ToString(nsACString& aResult) override;
-
-private:
-    virtual ~nsScriptErrorWithStack();
-    // Complete stackframe where the error happened.
-    // Must be SavedFrame object.
-    JS::Heap<JSObject*>  mStack;
-};
-
 /******************************************************************************
  * Handles pre/post script processing.
  */
diff --git a/js/xpconnect/src/xpcpublic.h b/js/xpconnect/src/xpcpublic.h
index fc8670d46..399cd2181 100644
--- a/js/xpconnect/src/xpcpublic.h
+++ b/js/xpconnect/src/xpcpublic.h
@@ -515,13 +515,50 @@ AllowCPOWsInAddon(const nsACString& addonId, bool allow);
 bool
 ExtraWarningsForSystemJS();
 
-class ErrorReport {
+class ErrorBase {
+  public:
+    nsString mErrorMsg;
+    nsString mFileName;
+    uint32_t mLineNumber;
+    uint32_t mColumn;
+
+    ErrorBase() : mLineNumber(0)
+                , mColumn(0)
+    {}
+
+    void Init(JSErrorBase* aReport);
+
+    void AppendErrorDetailsTo(nsCString& error);
+};
+
+class ErrorNote : public ErrorBase {
+  public:
+    void Init(JSErrorNotes::Note* aNote);
+
+    // Produce an error event message string from the given JSErrorNotes::Note.
+    // This may produce an empty string if aNote doesn't have a message
+    // attached.
+    static void ErrorNoteToMessageString(JSErrorNotes::Note* aNote,
+                                         nsAString& aString);
+
+    // Log the error note to the stderr.
+    void LogToStderr();
+};
+
+class ErrorReport : public ErrorBase {
   public:
     NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ErrorReport);
 
+    nsTArray<ErrorNote> mNotes;
+
+    nsCString mCategory;
+    nsString mSourceLine;
+    nsString mErrorMsgName;
+    uint64_t mWindowID;
+    uint32_t mFlags;
+    bool mIsMuted;
+
     ErrorReport() : mWindowID(0)
-                  , mLineNumber(0)
-                  , mColumn(0)
                   , mFlags(0)
                   , mIsMuted(false)
     {}
@@ -530,6 +567,7 @@ class ErrorReport {
               bool aIsChrome, uint64_t aWindowID);
     void Init(JSContext* aCx, mozilla::dom::Exception* aException,
               bool aIsChrome, uint64_t aWindowID);
+
     // Log the error report to the console.  Which console will depend on the
     // window id it was initialized with.
     void LogToConsole();
@@ -544,18 +582,8 @@ class ErrorReport {
     static void ErrorReportToMessageString(JSErrorReport* aReport,
                                            nsAString& aString);
 
-  public:
-
-    nsCString mCategory;
-    nsString mErrorMsgName;
-    nsString mErrorMsg;
-    nsString mFileName;
-    nsString mSourceLine;
-    uint64_t mWindowID;
-    uint32_t mLineNumber;
-    uint32_t mColumn;
-    uint32_t mFlags;
-    bool mIsMuted;
+    // Log the error report to the stderr.
+    void LogToStderr();
 
   private:
     ~ErrorReport() {}