Synthetic pinch gesture take scale factor as parameter.

content/browser/renderer_host/input/synthetic_pinch_gesture.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_INPUT_SYNTHETIC_PINCH_GESTURE_H_
 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_SYNTHETIC_PINCH_GESTURE_H_
 
 #include "base/time/time.h"
 #include "content/browser/renderer_host/input/synthetic_gesture.h"
 #include "content/browser/renderer_host/input/synthetic_gesture_target.h"
@@ skipping 35 matching lines @@
                          const base::TimeTicks& timestamp);
 
   void SetupCoordinatesAndStopTime(SyntheticGestureTarget* target);
   float GetDeltaForPointer0AtTime(const base::TimeTicks& timestamp) const;
   base::TimeTicks ClampTimestamp(const base::TimeTicks& timestamp) const;
   bool HasReachedTarget(const base::TimeTicks& timestamp) const;
 
   SyntheticPinchGestureParams params_;
   float start_y_0_;
   float start_y_1_;
+  float max_pointer_delta_0_;
   SyntheticGestureParams::GestureSourceType gesture_source_type_;
   GestureState state_;
   SyntheticWebTouchEvent touch_event_;
   base::TimeTicks start_time_;
   base::TimeTicks stop_time_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SyntheticPinchGesture);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_SYNTHETIC_PINCH_GESTURE_H_