ui: Add ref-counting to GLFence class.

ui/gl/gl_fence.h

Index: ui/gl/gl_fence.h
diff --git a/ui/gl/gl_fence.h b/ui/gl/gl_fence.h
index 31c16f72ab2170ba82a41a33ba9fc31d50168c1e..0f055273bf5d39557e38a74b59745c00b27a2b61 100644
--- a/ui/gl/gl_fence.h
+++ b/ui/gl/gl_fence.h
@@ -6,17 +6,17 @@
 #define UI_GL_GL_FENCE_H_
 
 #include "base/macros.h"
+#include "base/memory/ref_counted.h"
 #include "ui/gl/gl_export.h"
 
 namespace gl {
 
-class GL_EXPORT GLFence {
+class GL_EXPORT GLFence : public base::RefCounted<GLFence> {
  public:
   GLFence();
-  virtual ~GLFence();
 
   static bool IsSupported();
-  static GLFence* Create();
+  static scoped_refptr<GLFence> Create();
 
   virtual bool HasCompleted() = 0;
   virtual void ClientWait() = 0;
@@ -40,7 +40,12 @@ class GL_EXPORT GLFence {
   // Signal the fence.
   virtual void Signal();
 
+ protected:
+  virtual ~GLFence();
+
  private:
+  friend class base::RefCounted<GLFence>;
+
   DISALLOW_COPY_AND_ASSIGN(GLFence);
 };