base::RefCounted now DCHECKs when referenced from multiple threads.

ui/gl/gl_share_group.h

 // Copyright (c) 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 UI_GL_GL_SHARE_GROUP_H_
 #define UI_GL_GL_SHARE_GROUP_H_
 
 #include <set>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "ui/gl/gl_export.h"
 
 namespace gfx {
 
 class GLContext;
 
 // A group of GL contexts that share an ID namespace.
-class GL_EXPORT GLShareGroup : public base::RefCounted<GLShareGroup> {
+// TODO(mgiuca): Avoid using UnsafeRefCounted. http://crbug.com/469952.
+class GL_EXPORT GLShareGroup : public base::UnsafeRefCounted<GLShareGroup> {
  public:
   GLShareGroup();
 
   // These two should only be called from the constructor and destructor of
   // GLContext.
   void AddContext(GLContext* context);
   void RemoveContext(GLContext* context);
 
   // Returns a handle to any initialized context in the share group or NULL if
   // there are no initialized contexts in the share group.
   void* GetHandle();
 
   // Returns a pointer to any initialized context in the share group
   // or NULL if there are no initialized contexts in the share group.
   GLContext* GetContext();
 
   // Sets and returns the unique shared GL context. Used for context
   // virtualization.
   void SetSharedContext(GLContext* context);
   GLContext* GetSharedContext();
 
 #if defined(OS_MACOSX)
   // Sets and returns the ID of the renderer that all contexts in this share
   // group should be on.
   void SetRendererID(int renderer_id);
   int GetRendererID();
 #endif
 
  private:
-  friend class base::RefCounted<GLShareGroup>;
+  friend class base::UnsafeRefCounted<GLShareGroup>;
 
   ~GLShareGroup();
 
   // References to GLContext are by raw pointer to avoid a reference count
   // cycle.
   typedef std::set<GLContext*> ContextSet;
   ContextSet contexts_;
 
   GLContext* shared_context_;
 
 #if defined(OS_MACOSX)
   int renderer_id_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(GLShareGroup);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_SHARE_GROUP_H_