Synthesize ctrl-wheel events on touchpad pinch

content/browser/renderer_host/input/input_router_impl.h

Index: content/browser/renderer_host/input/input_router_impl.h
diff --git a/content/browser/renderer_host/input/input_router_impl.h b/content/browser/renderer_host/input/input_router_impl.h
index 6630c9197ca3356439bae6e5c3ff4ae0e761f794..e2ef55ac79cb12fb3584e5f636f906a30662e5a2 100644
--- a/content/browser/renderer_host/input/input_router_impl.h
+++ b/content/browser/renderer_host/input/input_router_impl.h
@@ -118,6 +118,10 @@ private:
                        const ui::LatencyInfo& latency_info,
                        bool is_keyboard_shortcut);
 
+  void SendSyntheticWheelEventForPinch(
+      const blink::WebGestureEvent& pinch_event,
+      const ui::LatencyInfo& latency_info);
+
   // IPC message handlers
   void OnInputEventAck(blink::WebInputEvent::Type event_type,
                        InputEventAckState ack_result,
@@ -221,6 +225,17 @@ private:
   bool mouse_wheel_pending_;
   MouseWheelEventWithLatencyInfo current_wheel_event_;
 
+  // Whether there is a Touchpad GesturePinchUpdate currently pending, waiting
+  // for it's synthetic WheelEvent to be handled.
+  bool pending_touchpad_pinch_;
+  // When |mouse_wheel_pending_| is true, indicates whether the current wheel
+  // event is in fact a synthetic event for touchpad pinch.
+  bool current_wheel_event_is_for_pinch_;
+  // When |pending_touchpad_pinch_| is true, this is the synthetic wheel event
+  // that will be or (if |current_wheel_event_is_for_pinch_ is true) has
+  // already been sent representing the pinch.
+  MouseWheelEventWithLatencyInfo wheel_event_for_pending_pinch_;
+
   // (Similar to |next_mouse_move_|.) The next mouse wheel events to send.
   // Unlike mouse moves, mouse wheel events received while one is pending are
   // coalesced (by accumulating deltas) if they match the previous event in