Unset GL Api when releasing a context.

ui/gl/gl_context_cgl.cc

 // 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.
 
 #include "ui/gl/gl_context_cgl.h"
 
 #include <OpenGL/CGLRenderers.h>
 #include <OpenGL/CGLTypes.h>
 #include <vector>
 
@@ skipping 179 matching lines @@
   SetRealGLApi();
 
   SetCurrent(surface);
   if (!InitializeExtensionBindings()) {
     ReleaseCurrent(surface);
     return false;
   }
 
   if (!surface->OnMakeCurrent(this)) {
     LOG(ERROR) << "Unable to make gl context current.";
+    ReleaseCurrent(surface);
     return false;
   }
 
   return true;
 }
 
 void GLContextCGL::ReleaseCurrent(GLSurface* surface) {
   if (!IsCurrent(surface))
     return;
 
@@ skipping 85 matching lines @@
 
 GLContextCGL::~GLContextCGL() {
   Destroy();
 }
 
 GpuPreference GLContextCGL::GetGpuPreference() {
   return gpu_preference_;
 }
 
 }  // namespace gfx