Merge 141357

Merge 141357
> [Chromium] WebPluginContainerImpl adding imbalanced touch handler refs
> https://bugs.webkit.org/show_bug.cgi?id=108381
> 
> Reviewed by James Robinson.
> 
> Source/WebKit/chromium:
> 
> WebPluginContainerImpl would call Document::didAddTouchEventHandler every time the plugin requested
> touch events. Some plugins make this request more than once, leading to an imbalance in Document's
> touch event handler map, and a stale node pointer when the plugin is destroyed. This change
> has WebPluginContainerImpl only add one ref for the plugin at a time.
> 
> * src/WebPluginContainerImpl.cpp:
> (WebKit::WebPluginContainerImpl::requestTouchEventType):
> 
> Tools:
> 
> * DumpRenderTree/chromium/TestRunner/src/WebTestPlugin.cpp: Adding an attribute that
> tickles the case in WebPluginContainerImpl that imbalanced touch handler refs in Document.
> 
> LayoutTests:
> 
> * platform/chromium/plugins/re-request-touch-events-crash-expected.txt: Added.
> * platform/chromium/plugins/re-request-touch-events-crash.html: Added.
> 

TBR=leviw@chromium.org
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=141609