Remove external begin frame source parameter and settings

cc/trees/tree_synchronizer_unittest.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/trees/tree_synchronizer.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <set>
@@ skipping 546 matching lines @@
   host_impl->CreatePendingTree();
   host_->CommitAndCreatePendingTree();
   host_impl->ActivateSyncTree();
 
   EXPECT_EQ(scroll_layer->id(),
             host_impl->active_tree()->CurrentlyScrollingLayer()->id());
 }
 
 TEST_F(TreeSynchronizerTest, SynchronizeScrollTreeScrollOffsetMap) {
   host_->InitializeSingleThreaded(&single_thread_client_,
-                                  base::ThreadTaskRunnerHandle::Get(), nullptr);
+                                  base::ThreadTaskRunnerHandle::Get());
   LayerTreeSettings settings;
   FakeLayerTreeHostImplClient client;
   FakeImplTaskRunnerProvider task_runner_provider;
   FakeRenderingStatsInstrumentation stats_instrumentation;
   TestSharedBitmapManager shared_bitmap_manager;
   TestTaskGraphRunner task_graph_runner;
   FakeLayerTreeHostImpl* host_impl = host_->host_impl();
   host_impl->CreatePendingTree();
 
   scoped_refptr<Layer> layer_tree_root = Layer::Create();
@@ skipping 75 matching lines @@
   scroll_offset_map[scroll_layer->id()]->PullDeltaForMainThread();
   scroll_offset_map[scroll_layer->id()]->SetCurrent(gfx::ScrollOffset(40, 50));
   scroll_offset_map[scroll_layer->id()]->PushFromMainThread(
       gfx::ScrollOffset(100, 100));
   scroll_offset_map[scroll_layer->id()]->PushPendingToActive();
   EXPECT_TRUE(is_equal(scroll_offset_map, scroll_tree.scroll_offset_map()));
 }
 
 TEST_F(TreeSynchronizerTest, RefreshPropertyTreesCachedData) {
   host_->InitializeSingleThreaded(&single_thread_client_,
-                                  base::ThreadTaskRunnerHandle::Get(), nullptr);
+                                  base::ThreadTaskRunnerHandle::Get());
   LayerTreeSettings settings;
   FakeLayerTreeHostImplClient client;
   FakeImplTaskRunnerProvider task_runner_provider;
   FakeRenderingStatsInstrumentation stats_instrumentation;
   TestSharedBitmapManager shared_bitmap_manager;
   TestTaskGraphRunner task_graph_runner;
   FakeLayerTreeHostImpl* host_impl = host_->host_impl();
   host_impl->CreatePendingTree();
 
   scoped_refptr<Layer> layer_tree_root = Layer::Create();
@@ skipping 25 matching lines @@
   host_->CommitAndCreatePendingTree();
   host_impl->ActivateSyncTree();
   EXPECT_EQ(
       CombinedAnimationScale(0.f, 0.f),
       host_impl->active_tree()->property_trees()->GetAnimationScales(
           transform_layer->transform_tree_index(), host_impl->active_tree()));
 }
 
 }  // namespace
 }  // namespace cc