Re-route Touchscreen GesturePinch events to root view.

content/browser/renderer_host/render_widget_host_input_event_router.h

Index: content/browser/renderer_host/render_widget_host_input_event_router.h
diff --git a/content/browser/renderer_host/render_widget_host_input_event_router.h b/content/browser/renderer_host/render_widget_host_input_event_router.h
index 70f8b05b8e241715ea116565b79a6518c98a7c64..0828cc178df7c68282c484e9aa5b3b1e71a03437 100644
--- a/content/browser/renderer_host/render_widget_host_input_event_router.h
+++ b/content/browser/renderer_host/render_widget_host_input_event_router.h
@@ -137,6 +137,10 @@ class CONTENT_EXPORT RenderWidgetHostInputEventRouter
   TargetData bubbling_gesture_scroll_target_;
   TargetData first_bubbling_scroll_target_;
   int active_touches_;
+  // Keep track of when we are between GesturePinchBegin and GesturePinchEnd
+  // inclusive, as we need to route these events (and anything in between) to
+  // the main frame.
+  bool in_touchscreen_gesture_pinch_;
   std::unordered_map<cc::SurfaceId, HittestData, cc::SurfaceIdHash>
       hittest_data_;