cc: Move solid color scrollbar layer data in a seperate struct.

cc/layers/solid_color_scrollbar_layer.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 CC_LAYERS_SOLID_COLOR_SCROLLBAR_LAYER_H_
 #define CC_LAYERS_SOLID_COLOR_SCROLLBAR_LAYER_H_
 
 #include "base/macros.h"
 #include "cc/base/cc_export.h"
 #include "cc/layers/layer.h"
@@ skipping 39 matching lines @@
 
   // Layer overrides for proto conversions.
   void SetTypeForProtoSerialization(proto::LayerNode* proto) const override;
   void LayerSpecificPropertiesToProto(proto::LayerProperties* proto) override;
   void FromLayerSpecificPropertiesProto(
       const proto::LayerProperties& proto) override;
 
  private:
   friend class LayerSerializationTest;
 
-  int scroll_layer_id_;
-  ScrollbarOrientation orientation_;
-  int thumb_thickness_;
-  int track_start_;
-  bool is_left_side_vertical_scrollbar_;
+  // Encapsulate all data, callbacks, interfaces received from the embedder.
+  struct SolidColorScrollbarLayerInputs {
+    SolidColorScrollbarLayerInputs(ScrollbarOrientation orientation,
+                                   int thumb_thickness,
+                                   int track_start,
+                                   bool is_left_side_vertical_scrollbar,
+                                   int scroll_layer_id);
+    ~SolidColorScrollbarLayerInputs();
+
+    int scroll_layer_id;
+    ScrollbarOrientation orientation;
+    int thumb_thickness;
+    int track_start;
+    bool is_left_side_vertical_scrollbar;
+  };
+
+  SolidColorScrollbarLayerInputs solid_color_scrollbar_layer_inputs_;
 
   DISALLOW_COPY_AND_ASSIGN(SolidColorScrollbarLayer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_SOLID_COLOR_SCROLLBAR_LAYER_H_