Compute damage rect for Cast video compositing

cc/output/overlay_strategy_cast_underlay.h

Index: cc/output/overlay_strategy_cast_underlay.h
diff --git a/cc/output/overlay_strategy_cast_underlay.h b/cc/output/overlay_strategy_cast_underlay.h
new file mode 100644
index 0000000000000000000000000000000000000000..e8d4b385ad1a839899cf7bc02fb3f99aa5ba8ec9
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+++ b/cc/output/overlay_strategy_cast_underlay.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_OUTPUT_OVERLAY_STRATEGY_CAST_UNDERLAY_H_
+#define CC_OUTPUT_OVERLAY_STRATEGY_CAST_UNDERLAY_H_
+
+#include "base/macros.h"
+#include "cc/output/overlay_strategy_underlay.h"
+
+namespace cc {
+
+class OverlayCandidateValidator;
+
+// Similar to underlay strategy but with cast-specific damage rect calculation.
+class CC_EXPORT OverlayStrategyCastUnderlay : public OverlayStrategyUnderlay {
+ public:
+  explicit OverlayStrategyCastUnderlay(
+      OverlayCandidateValidator* capability_checker);
+  ~OverlayStrategyCastUnderlay() override;
+
+  bool Attempt(ResourceProvider* resource_provider,
+               RenderPass* render_pass,
+               OverlayCandidateList* candidate_list) override;
+
+  bool GetSwapWithDamageRect(gfx::Rect* rect) override;
+
+ private:
+  bool have_swap_with_damage_rect_;
+  gfx::Rect swap_with_damage_rect_;
+
+  DISALLOW_COPY_AND_ASSIGN(OverlayStrategyCastUnderlay);
+};
+
+}  // namespace cc
+
+#endif  // CC_OUTPUT_OVERLAY_STRATEGY_CAST_UNDERLAY_H_