Synthetic pinch gesture take scale factor as parameter.

content/browser/renderer_host/input/synthetic_gesture_target_aura.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_GESTURE_TARGET_AURA_H_
 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_SYNTHETIC_GESTURE_TARGET_AURA_H_
 
 #include "base/time/time.h"
 #include "content/browser/renderer_host/input/synthetic_gesture_target_base.h"
 #include "content/common/input/synthetic_gesture_params.h"
@@ skipping 22 matching lines @@
       const blink::WebMouseWheelEvent& web_wheel,
       const ui::LatencyInfo& latency_info) OVERRIDE;
   virtual void DispatchWebMouseEventToPlatform(
       const blink::WebMouseEvent& web_mouse,
       const ui::LatencyInfo& latency_info) OVERRIDE;
 
   // SyntheticGestureTarget:
   virtual SyntheticGestureParams::GestureSourceType
       GetDefaultSyntheticGestureSourceType() const OVERRIDE;
 
-  virtual int GetTouchSlopInDips() const OVERRIDE;
+  virtual float GetTouchSlopInDips() const OVERRIDE;
+
+  virtual float GetMinScalingSpanInDips() const OVERRIDE;
 
  private:
   aura::Window* GetWindow() const;
 
   DISALLOW_COPY_AND_ASSIGN(SyntheticGestureTargetAura);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_SYNTHETIC_GESTURE_TARGET_AURA_H_