Implement pinch-zoom scaling for main-frame scrollbars and pinch-zoom overlay scrollbars.

cc/animation.h

 // Copyright 2012 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 CC_ANIMATION_H_
 #define CC_ANIMATION_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "cc/cc_export.h"
@@ skipping 89 matching lines @@
         ControllingInstance = 0,
         NonControllingInstance
     };
 
     scoped_ptr<Animation> clone(InstanceType) const;
     scoped_ptr<Animation> cloneAndInitialize(InstanceType, RunState initialRunState, double startTime) const;
     bool isControllingInstance() const { return m_isControllingInstance; }
 
     void pushPropertiesTo(Animation*) const;
 
+    void setIsImplAnimationOnly(bool isImplOnly) { m_isImplAnimationOnly = isImplOnly; }
+    bool isImplAnimationOnly() { return  m_isImplAnimationOnly; }
+
 private:
     Animation(scoped_ptr<AnimationCurve>, int animationId, int groupId, TargetProperty);
 
     scoped_ptr<AnimationCurve> m_curve;
 
     // IDs are not necessarily unique.
     int m_id;
 
     // Animations that must be run together are called 'grouped' and have the same group id
     // Grouped animations are guaranteed to start at the same time and no other animations
@@ skipping 28 matching lines @@
 
     // Animations lead dual lives. An active animation will be conceptually owned by
     // two controllers, one on the impl thread and one on the main. In reality, there
     // will be two separate Animation instances for the same animation. They
     // will have the same group id and the same target property (these two values
     // uniquely identify an animation). The instance on the impl thread is the instance
     // that ultimately controls the values of the animating layer and so we will refer
     // to it as the 'controlling instance'.
     bool m_isControllingInstance;
 
+    bool m_isImplAnimationOnly;
+
     DISALLOW_COPY_AND_ASSIGN(Animation);
 };
 
 } // namespace cc
 
 #endif  // CC_ANIMATION_H_