Use float for scroll offset.

third_party/WebKit/Source/platform/graphics/CompositorMutableState.h

 // Copyright 2016 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 CompositorMutableState_h
 #define CompositorMutableState_h
 
 #include "platform/PlatformExport.h"
 
 class SkMatrix44;
@@ skipping 13 matching lines @@
                          cc::LayerImpl* main,
                          cc::LayerImpl* scroll);
   ~CompositorMutableState();
 
   double opacity() const;
   void setOpacity(double);
 
   const SkMatrix44& transform() const;
   void setTransform(const SkMatrix44&);
 
-  double scrollLeft() const;
-  void setScrollLeft(double);
+  float scrollLeft() const;
+  void setScrollLeft(float);
 
-  double scrollTop() const;
-  void setScrollTop(double);
+  float scrollTop() const;
+  void setScrollTop(float);
 
  private:
   CompositorMutation* m_mutation;
   cc::LayerImpl* m_mainLayer;
   cc::LayerImpl* m_scrollLayer;
 };
 
 }  // namespace blink
 
 #endif  // CompositorMutableState_h