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

ui/gl/gl_share_group.h

Index: ui/gl/gl_share_group.h
diff --git a/ui/gl/gl_share_group.h b/ui/gl/gl_share_group.h
index 1deed63c541c1584becd2fa0fc954f6392a5d8e9..d3210c77e184822e88f725a24a19bb63fc76822b 100644
--- a/ui/gl/gl_share_group.h
+++ b/ui/gl/gl_share_group.h
@@ -16,7 +16,8 @@ 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();
 
@@ -46,7 +47,7 @@ class GL_EXPORT GLShareGroup : public base::RefCounted<GLShareGroup> {
 #endif
 
  private:
-  friend class base::RefCounted<GLShareGroup>;
+  friend class base::UnsafeRefCounted<GLShareGroup>;
 
   ~GLShareGroup();