Update Linux to use scoped_refptr<T>::get() rather than implicit "operator T*"

cc/test/layer_tree_test.cc

 // Copyright 2011 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 "cc/test/layer_tree_test.h"
 
 #include "base/command_line.h"
 #include "cc/animation/animation.h"
 #include "cc/animation/animation_registrar.h"
 #include "cc/animation/layer_animation_controller.h"
@@ skipping 375 matching lines @@
   proxy()->MainThreadTaskRunner()->PostTask(
       FROM_HERE,
       base::Bind(&LayerTreeTest::DispatchSetVisible,
                  main_thread_weak_ptr_,
                  visible));
 }
 
 void LayerTreeTest::DoBeginTest() {
   client_ = LayerTreeHostClientForTesting::Create(this);
 
-  DCHECK(!impl_thread_ || impl_thread_->message_loop_proxy());
+  DCHECK(!impl_thread_ || impl_thread_->message_loop_proxy().get());
   layer_tree_host_ = LayerTreeHostForTesting::Create(
       this,
       client_.get(),
       settings_,
       impl_thread_ ? impl_thread_->message_loop_proxy() : NULL);
   ASSERT_TRUE(layer_tree_host_);
 
   started_ = true;
   beginning_ = true;
   SetupTree();
@@ skipping 214 matching lines @@
 
 scoped_refptr<cc::ContextProvider> LayerTreeTest::
     OffscreenContextProviderForCompositorThread() {
   if (!compositor_thread_contexts_.get() ||
       compositor_thread_contexts_->DestroyedOnMainThread())
     compositor_thread_contexts_ = FakeContextProvider::Create();
   return compositor_thread_contexts_;
 }
 
 }  // namespace cc