gfx::Image is now thread-safe.

ui/gfx/image/image.h

Index: ui/gfx/image/image.h
diff --git a/ui/gfx/image/image.h b/ui/gfx/image/image.h
index 6f0e9266e7b8a017f94ccda3e4e94fdc12960ec4..e3ee6091f9d685a43c23609cd81a28b5dfcb3254 100644
--- a/ui/gfx/image/image.h
+++ b/ui/gfx/image/image.h
@@ -49,6 +49,12 @@ class ImageRep;
 class ImageStorage;
 }
 
+// An image, backed by zero or more equivalent representations. When a specific

[Robert Sesek, 2014/04/17 16:56:58]

The comment for this class is at the top of the file.

+// representation is requested, the image data is converted to the desired
+// representation and cached, if it is not already.
+//
+// Image objects are copyable and thread safe. However, there are no thread
+// safety guarantees about the individual representations.
 class GFX_EXPORT Image {
  public:
   enum RepresentationType {
@@ -60,8 +66,6 @@ class GFX_EXPORT Image {
     kImageRepPNG,
   };
 
-  typedef std::map<RepresentationType, internal::ImageRep*> RepresentationMap;
-
   // Creates an empty image with no representations.
   Image();
 
@@ -188,6 +192,10 @@ class GFX_EXPORT Image {
       RepresentationType rep_type, bool must_exist) const;
 
   // Stores a representation into the map.
+  // NOTE: This is const, despite modifying the object's internal storage. It
+  // should only be used to add representations that are equivalent to an
+  // existing representation (i.e., it should not affect the externally visible
+  // state of the object).
   void AddRepresentation(internal::ImageRep* rep) const;
 
   // Internal class that holds all the representations. This allows the Image to