cc: Split Proxy to eliminate unnecessary dependencies on the impl side

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 "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "base/thread_task_runner_handle.h"
@@ skipping 370 matching lines @@
     LayerTreeHostImpl::NotifyReadyToDraw();
     test_hooks_->NotifyReadyToDrawOnThread(this);
   }
 
   void NotifyAllTileTasksCompleted() override {
     LayerTreeHostImpl::NotifyAllTileTasksCompleted();
     test_hooks_->NotifyAllTileTasksCompleted(this);
   }
 
   void BlockNotifyReadyToActivateForTesting(bool block) override {
-    CHECK(proxy()->ImplThreadTaskRunner())
+    CHECK(task_runner_provider()->ImplThreadTaskRunner())
         << "Not supported for single-threaded mode.";
     block_notify_ready_to_activate_for_testing_ = block;
     if (!block && notify_ready_to_activate_was_blocked_) {
       NotifyReadyToActivate();
       notify_ready_to_activate_was_blocked_ = false;
     }
   }
 
   void ActivateSyncTree() override {
     test_hooks_->WillActivateTreeOnThread(this);
@@ skipping 595 matching lines @@
 LayerTreeHost* LayerTreeTest::layer_tree_host() {
   // We check for a null proxy here as we sometimes ask for the layer tree host
   // when the proxy does not exist, often for checking settings after a test has
   // completed. For example, LTHPixelResourceTest::RunPixelResourceTest. See
   // elsewhere in this file for other examples.
   DCHECK(!proxy() || proxy()->IsMainThread() || proxy()->IsMainThreadBlocked());
   return layer_tree_host_.get();
 }
 
 }  // namespace cc