Add UMA metric for tracking root level listeners for blocking touch.

third_party/WebKit/Source/core/events/TouchEvent.h

Index: third_party/WebKit/Source/core/events/TouchEvent.h
diff --git a/third_party/WebKit/Source/core/events/TouchEvent.h b/third_party/WebKit/Source/core/events/TouchEvent.h
index 4bb598dc6c385cf614f029f82e7e3d20ac94974e..5b2fff25eb4c491448cf2aaa6edf6d5e19b1c1f1 100644
--- a/third_party/WebKit/Source/core/events/TouchEvent.h
+++ b/third_party/WebKit/Source/core/events/TouchEvent.h
@@ -48,11 +48,11 @@ public:
     static TouchEvent* create(TouchList* touches,
         TouchList* targetTouches, TouchList* changedTouches,
         const AtomicString& type, AbstractView* view,
-        PlatformEvent::Modifiers modifiers, bool cancelable, bool causesScrollingIfUncanceled,
+        PlatformEvent::Modifiers modifiers, bool cancelable, bool causesScrollingIfUncanceled, bool firstTouchMoveOrStart,
         double platformTimeStamp)
     {
         return new TouchEvent(touches, targetTouches, changedTouches, type, view,
-            modifiers, cancelable, causesScrollingIfUncanceled, platformTimeStamp);
+            modifiers, cancelable, causesScrollingIfUncanceled, firstTouchMoveOrStart, platformTimeStamp);
     }
 
     static TouchEvent* create(const AtomicString& type, const TouchEventInit& initializer)
@@ -82,6 +82,8 @@ public:
 
     void preventDefault() override;
 
+    void doneDispatchingEventAtCurrentTarget() override;
+
     EventDispatchMediator* createMediator() override;
 
     DECLARE_VIRTUAL_TRACE();
@@ -92,6 +94,7 @@ private:
         TouchList* changedTouches, const AtomicString& type,
         AbstractView*, PlatformEvent::Modifiers,
         bool cancelable, bool causesScrollingIfUncanceled,
+        bool firstTouchMoveOrStart,
         double platformTimeStamp);
     TouchEvent(const AtomicString&, const TouchEventInit&);
 
@@ -99,6 +102,8 @@ private:
     Member<TouchList> m_targetTouches;
     Member<TouchList> m_changedTouches;
     bool m_causesScrollingIfUncanceled;
+    bool m_firstTouchMoveOrStart;
+    bool m_defaultPreventedBeforeCurrentTarget;
 };
 
 class TouchEventDispatchMediator final : public EventDispatchMediator {