Adds support for hittesting points on surface quads

cc/surfaces/surface_hittest.h

+// Copyright 2015 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_SURFACES_SURFACE_HITTEST_H_
+#define CC_SURFACES_SURFACE_HITTEST_H_
+
+#include "cc/surfaces/surface_id.h"
+#include "cc/surfaces/surfaces_export.h"
+
+namespace gfx {
+class Point;
+}
+
+namespace cc {
+class CC_SURFACES_EXPORT SurfaceManager;
+
+class SurfaceHittest {
+ public:
+  explicit SurfaceHittest(SurfaceManager* manager);
+  ~SurfaceHittest();
+
+  SurfaceId Hittest(SurfaceId surface_id, const gfx::Point& point);

[jbauman, 2015/07/31 22:49:27]

You might also need to return the transformed location in the context of this
Surface; is there any other way to tell the renderer where the click (or
whatever) actually was?

[lfg, 2015/08/04 21:21:42]

Indeed, you're right. For some context, today this transformation happens in the
parent renderer.

+
+ private:
+  SurfaceManager* manager_;

[dcheng, 2015/08/01 00:48:47]

Nit: SurfaceManager* const, since it can't change for the lifetime of this
class.

[lfg, 2015/08/04 21:21:42]

Done.

+};
+}  // namespace cc
+
+#endif  // CC_SURFACES_SURFACE_HITTEST_H_