Start of hardware overlay support in CC with Ubercompositor.

cc/output/overlay_candidate_validator.h

Index: cc/output/overlay_candidate_validator.h
diff --git a/cc/output/overlay_candidate_validator.h b/cc/output/overlay_candidate_validator.h
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index 0000000000000000000000000000000000000000..026f4f3b696b7866fc6fd49be8eac301ca7318d9
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+++ b/cc/output/overlay_candidate_validator.h
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+// Copyright 2014 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_CANDIDATE_VALIDATOR_H_
+#define CC_OUTPUT_OVERLAY_CANDIDATE_VALIDATOR_H_
+
+#include <vector>
+
+#include "base/basictypes.h"
+#include "cc/base/cc_export.h"
+#include "cc/output/overlay_candidate.h"
+#include "cc/resources/resource_format.h"
+#include "ui/gfx/geometry/rect.h"
+
+namespace cc {
+
+// This class that can be used to answer questions about possible overlay
+// configurations for a particular output device.
+class CC_EXPORT OverlayCandidateValidator {
+ public:
+  typedef std::vector<OverlayCandidate> OverlayCandidateList;
+
+  // A list of possible overlay candidates is presented to this function.
+  // The expected result is that those candidates that can be in a separate
+  // plane are marked with |overlay_handled| set to true, otherwise they are
+  // to be traditionally composited.
+  virtual void CheckOverlaySupport(OverlayCandidateList* surfaces) = 0;
+
+  virtual ~OverlayCandidateValidator() {}
+};
+
+}  // namespace cc
+
+#endif  // CC_OUTPUT_OVERLAY_CANDIDATE_VALIDATOR_H_