cc/blimp: Set up the framework for state serialization.

cc/blimp/compositor_state_deserializer_client.h

Index: cc/blimp/compositor_state_deserializer_client.h
diff --git a/cc/blimp/compositor_state_deserializer_client.h b/cc/blimp/compositor_state_deserializer_client.h
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+++ b/cc/blimp/compositor_state_deserializer_client.h
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+// 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 CC_BLIMP_COMPOSITOR_STATE_DESERIALIZER_CLIENT_H_
+#define CC_BLIMP_COMPOSITOR_STATE_DESERIALIZER_CLIENT_H_
+
+#include "base/macros.h"
+#include "cc/base/cc_export.h"
+
+namespace gfx {
+class ScrollOffset;
+}  // namespace gfx
+
+namespace cc {
+
+class CC_EXPORT CompositorStateDeserializerClient {
+ public:
+  virtual ~CompositorStateDeserializerClient() {}
+
+  // Returns true if the given scroll offset update received from the engine
+  // should be ignored.
+  virtual bool ShouldRetainClientScroll(
+      int engine_layer_id,
+      const gfx::ScrollOffset& new_offset) = 0;
+
+  // Returns true if the given page scale update from the engine should be
+  // ignored.
+  virtual bool ShouldRetainClientPageScale(float new_page_scale) = 0;
+};
+
+}  // namespace cc
+
+#endif  // CC_BLIMP_COMPOSITOR_STATE_DESERIALIZER_CLIENT_H_