Honor the wheel event canScroll bit instead of trying to infer it from the ctrl modifier

Source/core/page/EventHandler.cpp

Index: Source/core/page/EventHandler.cpp
diff --git a/Source/core/page/EventHandler.cpp b/Source/core/page/EventHandler.cpp
index 6a38d592d4f6f3e0f6b880098b3d28ac8645f52c..723714824a0f1ceeebce111a012a5f86bb4d0c2b 100644
--- a/Source/core/page/EventHandler.cpp
+++ b/Source/core/page/EventHandler.cpp
@@ -2027,8 +2027,8 @@ void EventHandler::defaultWheelEventHandler(Node* startNode, WheelEvent* wheelEv
     if (!startNode || !wheelEvent)
         return;
 
-    // Ctrl + scrollwheel is reserved for triggering zoom in/out actions in Chromium.
-    if (wheelEvent->ctrlKey())
+    // Method suppressScroll() is reserved for triggering zoom in/out actions in Chromium.

[tdresser, 2014/11/27 15:06:09]

Method suppressScroll() ->
When scrolling is suppressed, we trigger zoom in/out instead.

[lanwei, 2014/12/02 15:48:10]

Done.

+    if (wheelEvent->suppressScroll())
         return;
 
     Node* stopNode = m_previousWheelScrolledNode.get();