1 files changed, 42 insertions, 0 deletions
diff --git a/cc/layers/contents_scaling_layer.h b/cc/layers/contents_scaling_layer.h
new file mode 100644
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+++ b/cc/layers/contents_scaling_layer.h
@@ -0,0 +1,42 @@
+// 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_LAYERS_CONTENTS_SCALING_LAYER_H_
+#define CC_LAYERS_CONTENTS_SCALING_LAYER_H_
+
+#include "cc/base/cc_export.h"
+#include "cc/layers/layer.h"
+
+namespace cc {
+
+// Base class for layers that need contents scale.
+// The content bounds are determined by bounds and scale of the contents.
+class CC_EXPORT ContentsScalingLayer : public Layer {
+ public:
+  virtual void CalculateContentsScale(
+      float ideal_contents_scale,
+      bool animating_transform_to_screen,
+      float* contents_scale_x,
+      float* contents_scale_y,
+      gfx::Size* content_bounds) OVERRIDE;
+
+  virtual void Update(
+    ResourceUpdateQueue* queue,
+    const OcclusionTracker* occlusion,
+    RenderingStats* stats) OVERRIDE;
+
+ protected:
+  ContentsScalingLayer();
+  virtual ~ContentsScalingLayer();
+
+  gfx::Size ComputeContentBoundsForScale(float scale_x, float scale_y) const;
+
+ private:
+  float last_update_contents_scale_x_;
+  float last_update_contents_scale_y_;
+};
+
+}  // namespace cc
+
+#endif  // CC_LAYERS_CONTENTS_SCALING_LAYER_H__