Convert gfx::internal::ImageStorage RefCountedThreadSafe

ui/gfx/image/image.cc

Index: ui/gfx/image/image.cc
diff --git a/ui/gfx/image/image.cc b/ui/gfx/image/image.cc
index 12254c17def66a5b46fb45db8257732cf14af173..d49c3119ba890279f813d9218630f72cb0096c8d 100644
--- a/ui/gfx/image/image.cc
+++ b/ui/gfx/image/image.cc
@@ -340,7 +340,7 @@ class ImageRepCocoa : public ImageRep {
 // The Storage class acts similarly to the pixels in a SkBitmap: the Image
 // class holds a refptr instance of Storage, which in turn holds all the
 // ImageReps. This way, the Image can be cheaply copied.
-class ImageStorage : public base::RefCounted<ImageStorage> {
+class ImageStorage : public base::RefCountedThreadSafe<ImageStorage> {
  public:
   ImageStorage(Image::RepresentationType default_type)
       : default_representation_type_(default_type)
@@ -367,7 +367,7 @@ class ImageStorage : public base::RefCounted<ImageStorage> {
 #endif  // defined(OS_MACOSX) && !defined(OS_IOS)
 
  private:
-  friend class base::RefCounted<ImageStorage>;
+  friend class base::RefCountedThreadSafe<ImageStorage>;
 
   ~ImageStorage() {}