cc: Make cc_unittests opt into real GL NullDraw contexts.

cc/test/layer_tree_pixel_test.h

 // Copyright 2013 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 CC_TEST_LAYER_TREE_PIXEL_TEST_H_
+#define CC_TEST_LAYER_TREE_PIXEL_TEST_H_
+
 #include <vector>
 
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "cc/resources/single_release_callback.h"
 #include "cc/test/layer_tree_test.h"
-
-#ifndef CC_TEST_LAYER_TREE_PIXEL_TEST_H_
-#define CC_TEST_LAYER_TREE_PIXEL_TEST_H_
+#include "ui/gl/gl_implementation.h"
 
 class SkBitmap;
 
 namespace gpu {
 class GLInProcessContext;
 }
 
 namespace cc {
 class CopyOutputRequest;
 class CopyOutputResult;
@@ skipping 63 matching lines @@
                              uint32 sync_point,
                              bool lost_resource);
 
   // Common CSS colors defined for tests to use.
   enum Colors {
     kCSSOrange = 0xffffa500,
     kCSSBrown = 0xffa52a2a,
     kCSSGreen = 0xff008000,
   };
 
+  gfx::DisableNullDrawGLBindings enable_pixel_output_;
   scoped_ptr<PixelComparator> pixel_comparator_;
   PixelTestType test_type_;
   scoped_refptr<Layer> content_root_;
   Layer* readback_target_;
   base::FilePath ref_file_;
   scoped_ptr<SkBitmap> result_bitmap_;
   std::vector<scoped_refptr<TextureLayer> > texture_layers_;
   int pending_texture_mailbox_callbacks_;
   bool impl_side_painting_;
 };
 
 }  // namespace cc
 
 #endif  // CC_TEST_LAYER_TREE_PIXEL_TEST_H_