Support GestureBegin and GestureEnd in ui::GestureProvider

ui/events/gesture_detection/gesture_provider.h

Index: ui/events/gesture_detection/gesture_provider.h
diff --git a/ui/events/gesture_detection/gesture_provider.h b/ui/events/gesture_detection/gesture_provider.h
index d8542194ccecf19864e1a337354629a2826a9816..f319791b83c2a5d87a062dae4badddfbd60908ad 100644
--- a/ui/events/gesture_detection/gesture_provider.h
+++ b/ui/events/gesture_detection/gesture_provider.h
@@ -33,6 +33,7 @@ class GESTURE_DETECTION_EXPORT GestureProvider {
     ScaleGestureDetector::Config scale_gesture_detector_config;
     SnapScrollController::Config snap_scroll_controller_config;
     bool disable_click_delay;
+    bool gesture_begin_end_types_enabled;

[jdduke (slow), 2014/04/03 22:03:28]

Maybe a short comment explaining what this does?  I should have added one for
|disable_click_delay| as well.

[tdresser, 2014/04/04 16:39:31]

Done. Please double check, particularly the comment I added for
disable_click_delay.

   };
 
   GestureProvider(const Config& config, GestureProviderClient* client);
@@ -59,6 +60,9 @@ class GESTURE_DETECTION_EXPORT GestureProvider {
   // detection allows for rapid and responsive single-tap gestures.
   void SetDoubleTapSupportForPageEnabled(bool enabled);
 
+  // Update whether GestureBegin and GestureEnd events are supported.
+  void SetBeginEndTypesEnabled(bool enabled);
+
   // Whether a scroll gesture is in-progress.
   bool IsScrollInProgress() const;
 
@@ -93,6 +97,10 @@ class GESTURE_DETECTION_EXPORT GestureProvider {
   bool SendLongTapIfNecessary(const MotionEvent& event);
   void EndTouchScrollIfNecessary(base::TimeTicks time,
                                  bool send_scroll_end_event);
+  void OnTouchEventHandlingBegin(const MotionEvent& event);
+  void OnTouchEventHandlingEnd(const MotionEvent& event,
+                               bool handled,
+                               bool was_touch_scrolling);
 
   GestureProviderClient* const client_;
 
@@ -124,6 +132,8 @@ class GESTURE_DETECTION_EXPORT GestureProvider {
   // opened after a GESTURE_LONG_PRESS, this is used to insert a
   // GESTURE_TAP_CANCEL for removing any ::active styling.
   base::TimeTicks current_longpress_time_;
+
+  bool gesture_begin_end_types_enabled_;
 };
 
 }  //  namespace ui