Start of hardware overlay support in CC with Ubercompositor.

cc/output/overlay_processor.h

Index: cc/output/overlay_processor.h
diff --git a/cc/output/overlay_processor.h b/cc/output/overlay_processor.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_PROCESSOR_H_
+#define CC_OUTPUT_OVERLAY_PROCESSOR_H_
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "cc/base/cc_export.h"
+#include "cc/quads/render_pass.h"
+
+namespace cc {
+class OutputSurface;
+class ResourceProvider;
+
+class CC_EXPORT OverlayProcessor {
+ public:
+  class CC_EXPORT Strategy {
+   public:
+    virtual ~Strategy() {}
+    // Returns false if the strategy cannot be made to work with the
+    // current set of render passes. Returns true if the strategy was successful
+    // and adds any additional passes necessary to represent overlays to
+    // |render_passes_in_draw_order|.
+    virtual bool Attempt(RenderPassList* render_passes_in_draw_order) = 0;
+  };
+  typedef ScopedPtrVector<Strategy> StrategyList;
+
+  OverlayProcessor(OutputSurface* surface, ResourceProvider* resource_provider);
+  virtual ~OverlayProcessor();
+  // Virtual to allow testing different strategies.
+  virtual void Initialize();
+
+  void ProcessForOverlays(RenderPassList* render_passes_in_draw_order);
+
+ protected:
+  StrategyList strategies_;
+  OutputSurface* surface_;
+  ResourceProvider* resource_provider_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(OverlayProcessor);
+};
+
+}  // namespace cc
+
+#endif  // CC_OUTPUT_OVERLAY_PROCESSOR_H_