Animation start scale should be considered for the raster scale

cc/animation/animation_curve.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_ANIMATION_CURVE_H_
 #define CC_ANIMATION_ANIMATION_CURVE_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "cc/base/cc_export.h"
@@ skipping 67 matching lines @@
 
   // Returns true if this animation affects scale.
   virtual bool AffectsScale() const = 0;
 
   // Returns true if this animation is a translation.
   virtual bool IsTranslation() const = 0;
 
   // Returns true if this animation preserves axis alignment.
   virtual bool PreservesAxisAlignment() const = 0;
 
+  // Animation start scale
+  virtual bool AnimationStartScale(bool forward_direction,
+                                   float* start_scale) const = 0;
+
   // Set |max_scale| to the maximum scale along any dimension at the end of
   // intermediate animation target points (eg keyframe end points). When
   // |forward_direction| is true, the animation curve assumes it plays from
   // the first keyframe to the last, otherwise it assumes the opposite. Returns
   // false if the maximum scale cannot be computed.
   virtual bool MaximumTargetScale(bool forward_direction,
                                   float* max_scale) const = 0;
 
   // Partial Animation implementation.
   CurveType Type() const override;
 };
 
 class CC_EXPORT FilterAnimationCurve : public AnimationCurve {
  public:
   ~FilterAnimationCurve() override {}
 
   virtual FilterOperations GetValue(base::TimeDelta t) const = 0;
   virtual bool HasFilterThatMovesPixels() const = 0;
 
   // Partial Animation implementation.
   CurveType Type() const override;
 };
 
 }  // namespace cc
 
 #endif  // CC_ANIMATION_ANIMATION_CURVE_H_