cc: Add some impl-side painting stub classes and APIs

cc/picture.h

+// Copyright 2012 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_PICTURE_H_
+#define CC_PICTURE_H_
+
+#include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
+#include "cc/cc_export.h"
+#include "third_party/skia/include/core/SkPicture.h"
+#include "ui/gfx/rect.h"
+
+namespace cc {
+
+class ContentLayerClient;
+
+class CC_EXPORT Picture
+    : public base::RefCountedThreadSafe<Picture> {
+public:
+  scoped_refptr<Picture> create(ContentLayerClient*, gfx::Rect);
+
+  const gfx::Rect& rect();
+  scoped_refptr<Picture> clone();
+
+protected:
+  Picture();
+  ~Picture();
+
+  gfx::Rect m_rect;
+  SkPicture m_picture;
+
+private:
+  friend class base::RefCountedThreadSafe<Picture>;
+
+  DISALLOW_COPY_AND_ASSIGN(Picture);
+};
+
+}  // namespace cc
+
+#endif  // CC_PICTURE_H_