Catch uncaught promise rejections from V8 and log to console.

Source/core/dom/ExecutionContext.h

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2012 Google Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 67 matching lines @@
     virtual void postTask(PassOwnPtr<ExecutionContextTask>) = 0; // Executes the task on context's thread asynchronously.
     virtual double timerAlignmentInterval() const = 0;
 
     virtual void reportBlockedScriptExecutionToInspector(const String& directiveText) = 0;
 
     virtual SecurityContext& securityContext() = 0;
     KURL contextURL() const { return virtualURL(); }
     KURL contextCompleteURL(const String& url) const { return virtualCompleteURL(url); }
 
     bool shouldSanitizeScriptError(const String& sourceURL, AccessControlStatus);
-    void reportException(PassRefPtrWillBeRawPtr<ErrorEvent>, int scriptId, PassRefPtrWillBeRawPtr<ScriptCallStack>, AccessControlStatus);
+    void reportException(PassRefPtrWillBeRawPtr<ErrorEvent>, int scriptId, PassRefPtrWillBeRawPtr<ScriptCallStack>, AccessControlStatus, bool isPromiseReject = false);
 
     virtual void addConsoleMessage(PassRefPtrWillBeRawPtr<ConsoleMessage>) = 0;
     virtual void logExceptionToConsole(const String& errorMessage, int scriptId, const String& sourceURL, int lineNumber, int columnNumber, PassRefPtrWillBeRawPtr<ScriptCallStack>) = 0;
 
     PublicURLManager& publicURLManager();
 
     // Active objects are not garbage collected even if inaccessible, e.g. because their activity may result in callbacks being invoked.
     bool hasPendingActivity();
 
     void suspendActiveDOMObjects();
@@ skipping 73 matching lines @@
 
     // The location of this member is important; to make sure contextDestroyed() notification on
     // ExecutionContext's members (notably m_timeouts) is called before they are destructed,
     // m_lifecycleNotifer should be placed *after* such members.
     OwnPtr<ContextLifecycleNotifier> m_lifecycleNotifier;
 };
 
 } // namespace blink
 
 #endif // ExecutionContext_h