Keep the user gesture when postMessage() across frames.

Source/core/frame/DOMWindow.cpp

Index: Source/core/frame/DOMWindow.cpp
diff --git a/Source/core/frame/DOMWindow.cpp b/Source/core/frame/DOMWindow.cpp
index a9c7d4dbf82096893986cf498a685d28b312a72e..f338ecb8921200c182e5a8e58d1254b4900ed1f5 100644
--- a/Source/core/frame/DOMWindow.cpp
+++ b/Source/core/frame/DOMWindow.cpp
@@ -112,7 +112,7 @@ namespace WebCore {
 
 class PostMessageTimer FINAL : public SuspendableTimer {
 public:
-    PostMessageTimer(DOMWindow& window, PassRefPtr<SerializedScriptValue> message, const String& sourceOrigin, PassRefPtr<DOMWindow> source, PassOwnPtr<MessagePortChannelArray> channels, SecurityOrigin* targetOrigin, PassRefPtr<ScriptCallStack> stackTrace)
+    PostMessageTimer(DOMWindow& window, PassRefPtr<SerializedScriptValue> message, const String& sourceOrigin, PassRefPtr<DOMWindow> source, PassOwnPtr<MessagePortChannelArray> channels, SecurityOrigin* targetOrigin, PassRefPtr<ScriptCallStack> stackTrace, bool userGesture)
         : SuspendableTimer(window.document())
         , m_window(window)
         , m_message(message)
@@ -121,6 +121,7 @@ public:
         , m_channels(channels)
         , m_targetOrigin(targetOrigin)
         , m_stackTrace(stackTrace)
+        , m_userGesture(userGesture)
     {
     }
 
@@ -131,6 +132,7 @@ public:
     }
     SecurityOrigin* targetOrigin() const { return m_targetOrigin.get(); }
     ScriptCallStack* stackTrace() const { return m_stackTrace.get(); }
+    bool userGesture() const { return m_userGesture; }
 
 private:
     virtual void fired() OVERRIDE
@@ -146,6 +148,7 @@ private:
     OwnPtr<MessagePortChannelArray> m_channels;
     RefPtr<SecurityOrigin> m_targetOrigin;
     RefPtr<ScriptCallStack> m_stackTrace;
+    bool m_userGesture;
 };
 
 static void disableSuddenTermination()
@@ -852,7 +855,7 @@ void DOMWindow::postMessage(PassRefPtr<SerializedScriptValue> message, const Mes
         stackTrace = createScriptCallStack(ScriptCallStack::maxCallStackSizeToCapture, true);
 
     // Schedule the message.
-    PostMessageTimer* timer = new PostMessageTimer(*this, message, sourceOrigin, source, channels.release(), target.get(), stackTrace.release());
+    PostMessageTimer* timer = new PostMessageTimer(*this, message, sourceOrigin, source, channels.release(), target.get(), stackTrace.release(), UserGestureIndicator::processingUserGesture());
     timer->startOneShot(0, FROM_HERE);
     timer->suspendIfNeeded();
 }
@@ -872,6 +875,10 @@ void DOMWindow::postMessageTimerFired(PassOwnPtr<PostMessageTimer> t)
     if (m_frame->loader().client()->willCheckAndDispatchMessageEvent(timer->targetOrigin(), event.get()))
         return;
 
+    scoped_ptr<UserGestureIndicator> gesture;
+    if (timer->userGesture())
+        gesture.reset(new UserGestureIndicator(DefinitelyProcessingNewUserGesture));

[abarth-chromium, 2014/03/24 17:39:47]

As written, this CL is incorrect because if you have a gesture and you queue up
100 postMessages, you'll get 100 new gesture tokens, which means you can perform
100 actions that consume user gestures instead of just one.  Instead, you need
to keep a reference to the gesture token instead of a flat bool.

+
     event->entangleMessagePorts(document());
     dispatchMessageEventWithOriginCheck(timer->targetOrigin(), event, timer->stackTrace());
 }