Update the nine patch layer to use UI resources

cc/resources/ui_resource_bitmap.h

 // Copyright 2013 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_RESOURCES_UI_RESOURCE_BITMAP_H_
 #define CC_RESOURCES_UI_RESOURCE_BITMAP_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "cc/base/cc_export.h"
+#include "skia/ext/refptr.h"
+#include "third_party/skia/include/core/SkPixelRef.h"
 #include "third_party/skia/include/core/SkTypes.h"
 #include "ui/gfx/size.h"
 
+class SkBitmap;
+
 namespace cc {
 
-// Ref-counted bitmap class (can’t use SkBitmap because of ETC1).  Thread-safety
-// ensures that both main and impl threads can hold references to the bitmap and
-// that asynchronous uploads are allowed.
-class CC_EXPORT UIResourceBitmap
-    : public base::RefCountedThreadSafe<UIResourceBitmap> {
+// A bitmap class that contains a ref-counted reference to a SkPixelRef* that
+// holds the content of the bitmap (cannot use SkBitmap because of ETC1).
+// Thread-safety (by ways of SkPixelRef) ensures that both main and impl threads
+// can hold references to the bitmap and that asynchronous uploads are allowed.
+class CC_EXPORT UIResourceBitmap {
  public:
   enum UIResourceFormat {
     RGBA8
   };
   enum UIResourceWrapMode {
     CLAMP_TO_EDGE,
     REPEAT
   };
 
-  // Takes ownership of “pixels”.
-  static scoped_refptr<UIResourceBitmap> Create(uint8_t* pixels,
-                                                UIResourceFormat format,
-                                                UIResourceWrapMode wrap_mode,
-                                                gfx::Size size);
-
   gfx::Size GetSize() const { return size_; }
   UIResourceFormat GetFormat() const { return format_; }
   UIResourceWrapMode GetWrapMode() const { return wrap_mode_; }
-  uint8_t* GetPixels() { return pixels_.get(); }
+  uint8_t* GetPixels() const;
+
+  // The constructor for the UIResourceBitmap.  User must ensure that |skbitmap|
+  // is immutable.  The SkBitmap format should be in 32-bit RGBA.  Wrap mode is
+  // unnecessary for most UI resources and is defaulted to CLAMP_TO_EDGE.
+  UIResourceBitmap(const SkBitmap& skbitmap,
+                   UIResourceWrapMode wrap_mode = CLAMP_TO_EDGE);
+
+  ~UIResourceBitmap();
 
  private:
-  friend class base::RefCountedThreadSafe<UIResourceBitmap>;
+  void Create(const skia::RefPtr<SkPixelRef>& pixel_ref,
+              UIResourceFormat format,
+              UIResourceWrapMode wrap_mode,
+              gfx::Size size);
 
-  UIResourceBitmap();
-  ~UIResourceBitmap();
-
-  scoped_ptr<uint8_t[]> pixels_;
+  skia::RefPtr<SkPixelRef> pixel_ref_;
   UIResourceFormat format_;
   UIResourceWrapMode wrap_mode_;
   gfx::Size size_;
-
-  DISALLOW_COPY_AND_ASSIGN(UIResourceBitmap);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_UI_RESOURCE_BITMAP_H_