Move NullDraw GL bindings and allow them to be disabled temporarily.

ui/gl/gl_implementation.h

Index: ui/gl/gl_implementation.h
diff --git a/ui/gl/gl_implementation.h b/ui/gl/gl_implementation.h
index 0881e10b32d378887da20aa30c0ebb3fef96e711..f163e07c1505c3b3ccf91660bbe117a237f18f98 100644
--- a/ui/gl/gl_implementation.h
+++ b/ui/gl/gl_implementation.h
@@ -52,9 +52,21 @@ GL_EXPORT bool InitializeDynamicGLBindings(GLImplementation implementation,
 // Initialize Debug logging wrappers for GL bindings.
 void InitializeDebugGLBindings();
 
-// Initialize stub methods for drawing operations in the GL bindings.
+// Initialize stub methods for drawing operations in the GL bindings. The
+// null draw bindings default to enabled, so that draw operations do nothing.
 void InitializeNullDrawGLBindings();
 
+// Once initialized, instantiating this turns the stub methods for drawing
+// operations off allowing drawing will occur while the object is alive.
+class GL_EXPORT DisableNullDrawGLBindings {
+ public:
+  DisableNullDrawGLBindings();
+  ~DisableNullDrawGLBindings();
+
+ private:
+  bool initial_enabled_;
+};
+
 GL_EXPORT void ClearGLBindings();
 
 // Set the current GL implementation.