Re-land: cc: Implement shared worker contexts.

cc/trees/layer_tree_host_unittest_context.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/trees/layer_tree_host.h"
 
 #include "base/basictypes.h"
 #include "cc/layers/delegated_frame_provider.h"
 #include "cc/layers/delegated_frame_resource_collection.h"
 #include "cc/layers/heads_up_display_layer.h"
@@ skipping 398 matching lines @@
     setos_counter_++;
     layer_tree_host()->SetOutputSurface(surface.Pass());
   }
 
   void HideAndReleaseOutputSurface() {
     EXPECT_TRUE(layer_tree_host()->proxy()->IsMainThread());
     layer_tree_host()->SetVisible(false);
     scoped_ptr<OutputSurface> surface =
         layer_tree_host()->ReleaseOutputSurface();
     CHECK(surface);
-    surface->context_provider()->DetachFromThread();
     MainThreadTaskRunner()->PostTask(
         FROM_HERE,
         base::Bind(&LayerTreeHostClientTakeAwayOutputSurface::MakeVisible,
                    base::Unretained(this)));
   }
 
   void DidInitializeOutputSurface() override {
     EXPECT_TRUE(layer_tree_host()->visible());
     if (setos_counter_ == 1) {
       MainThreadTaskRunner()->PostTask(
@@ skipping 1193 matching lines @@
   void AfterTest() override {}
 
   bool deferred_;
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(
     LayerTreeHostContextTestLoseAfterSendingBeginMainFrame);
 
 }  // namespace
 }  // namespace cc