Revert of cc: Single-threaded impl-side painting for unit tests

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 184 matching lines @@
   }
 
   virtual void NotifyReadyToActivate() OVERRIDE {
     if (block_notify_ready_to_activate_for_testing_)
       notify_ready_to_activate_was_blocked_ = true;
     else
       client_->NotifyReadyToActivate();
   }
 
   virtual void BlockNotifyReadyToActivateForTesting(bool block) OVERRIDE {
-    CHECK(settings().impl_side_painting);
-    CHECK(proxy()->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;
     }
   }
 
   virtual void ActivateSyncTree() OVERRIDE {
     test_hooks_->WillActivateTreeOnThread(this);
     LayerTreeHostImpl::ActivateSyncTree();
@@ skipping 405 matching lines @@
     ASSERT_TRUE(impl_thread_->Start());
   }
 
   main_task_runner_ = base::MessageLoopProxy::current();
 
   delegating_renderer_ = delegating_renderer;
 
   // Spend less time waiting for BeginFrame because the output is
   // mocked out.
   settings_.refresh_rate = 200.0;
-  settings_.impl_side_painting = impl_side_painting;
+  if (impl_side_painting) {
+    DCHECK(threaded)
+        << "Don't run single thread + impl side painting, it doesn't exist.";
+    settings_.impl_side_painting = true;
+  }
   InitializeSettings(&settings_);
 
   main_task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&LayerTreeTest::DoBeginTest, base::Unretained(this)));
 
   if (timeout_seconds_) {
     timeout_.Reset(base::Bind(&LayerTreeTest::Timeout, base::Unretained(this)));
     main_task_runner_->PostDelayedTask(
         FROM_HERE,
@@ skipping 53 matching lines @@
   return -1;
 }
 
 void LayerTreeTest::DestroyLayerTreeHost() {
   if (layer_tree_host_ && layer_tree_host_->root_layer())
     layer_tree_host_->root_layer()->SetLayerTreeHost(NULL);
   layer_tree_host_.reset();
 }
 
 }  // namespace cc