Synthetic pinch gesture take scale factor as parameter.

content/common/input/synthetic_pinch_gesture_params.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_COMMON_INPUT_SYNTHETIC_PINCH_GESTURE_PARAMS_H_
 #define CONTENT_COMMON_INPUT_SYNTHETIC_PINCH_GESTURE_PARAMS_H_
 
 #include "content/common/content_export.h"
 #include "content/common/input/synthetic_gesture_params.h"
 #include "ui/gfx/point.h"
 
 namespace content {
 
 struct CONTENT_EXPORT SyntheticPinchGestureParams
     : public SyntheticGestureParams {
  public:
   SyntheticPinchGestureParams();
   SyntheticPinchGestureParams(
       const SyntheticPinchGestureParams& other);
   virtual ~SyntheticPinchGestureParams();
 
   virtual GestureType GetGestureType() const OVERRIDE;
 
-  bool zoom_in;
-  int total_num_pixels_covered;
+  float scale_factor;
   gfx::Point anchor;
   int relative_pointer_speed_in_pixels_s;
 
   static const SyntheticPinchGestureParams* Cast(
       const SyntheticGestureParams* gesture_params);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_INPUT_SYNTHETIC_PINCH_GESTURE_PARAMS_H_