cc: Change the restrictions on overlays for video

cc/output/overlay_candidate.h

 // 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_H_
 #define CC_OUTPUT_OVERLAY_CANDIDATE_H_
 
 #include <vector>
 
 #include "cc/base/cc_export.h"
 #include "cc/resources/resource_format.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/overlay_transform.h"
 #include "ui/gfx/transform.h"
 
 namespace cc {
 
 class CC_EXPORT OverlayCandidate {
  public:
   static gfx::OverlayTransform GetOverlayTransform(
       const gfx::Transform& quad_transform,
       bool flipped);
+  // Apply transform |delta| to |in| and return the resulting transform,
+  // or OVERLAY_TRANSFORM_INVALID.
+  static gfx::OverlayTransform ModifyTransform(gfx::OverlayTransform in,
+                                               gfx::OverlayTransform delta);
   static gfx::Rect GetOverlayRect(const gfx::Transform& quad_transform,
                                   const gfx::Rect& rect);
 
   OverlayCandidate();
   ~OverlayCandidate();
 
   // Transformation to apply to layer during composition.
   gfx::OverlayTransform transform;
   // Format of the buffer to composite.
   ResourceFormat format;
@@ skipping 10 matching lines @@
   // To be modified by the implementer if this candidate can go into
   // an overlay.
   bool overlay_handled;
 };
 
 typedef std::vector<OverlayCandidate> OverlayCandidateList;
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_OVERLAY_CANDIDATE_H_