Remove external begin frame source parameter and settings

cc/layers/texture_layer_unittest.cc

 // Copyright 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 "cc/layers/texture_layer.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 73 matching lines @@
 
   MOCK_METHOD0(SetNeedsCommit, void());
   MOCK_METHOD0(SetNeedsUpdateLayers, void());
   MOCK_METHOD0(StartRateLimiter, void());
   MOCK_METHOD0(StopRateLimiter, void());
 
  private:
   explicit MockLayerTreeHost(LayerTreeHostInProcess::InitParams* params)
       : LayerTreeHostInProcess(params, CompositorMode::SINGLE_THREADED) {
     InitializeSingleThreaded(&single_thread_client_,
-                             base::ThreadTaskRunnerHandle::Get(), nullptr);
+                             base::ThreadTaskRunnerHandle::Get());
   }
 
   StubLayerTreeHostSingleThreadClient single_thread_client_;
 };
 
 class FakeTextureLayerClient : public TextureLayerClient {
  public:
   FakeTextureLayerClient() : mailbox_changed_(true) {}
 
   bool PrepareTextureMailbox(
@@ skipping 1348 matching lines @@
   base::ThreadChecker main_thread_;
   int callback_count_;
   scoped_refptr<Layer> root_;
   scoped_refptr<TextureLayer> layer_;
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(TextureLayerWithMailboxImplThreadDeleted);
 
 }  // namespace
 }  // namespace cc