cc: Make OutputSurface::BindToClient pure virtual and not return bool

cc/trees/layer_tree_host_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/layer_tree_host.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 5989 matching lines @@
   std::unique_ptr<OutputSurface> CreateDisplayOutputSurfaceOnThread(
       scoped_refptr<ContextProvider> compositor_context_provider) override {
     scoped_refptr<TestContextProvider> display_context_provider =
         TestContextProvider::Create();
     TestWebGraphicsContext3D* context3d =
         display_context_provider->UnboundTestContext3d();
     context3d->set_support_sync_query(true);
 #if defined(OS_MACOSX)
     context3d->set_support_texture_rectangle(true);
 #endif
+    display_context_provider->BindToCurrentThread();
     return LayerTreeTest::CreateDisplayOutputSurfaceOnThread(
         std::move(display_context_provider));
   }
 };
 
 // This test does pinching on the impl side which is not supported in single
 // thread.
 MULTI_THREAD_TEST_F(LayerTreeHostTestCrispUpAfterPinchEndsWithOneCopy);
 
 class RasterizeWithGpuRasterizationCreatesResources : public LayerTreeHostTest {
@@ skipping 1015 matching lines @@
     EndTest();
   }
 
   void AfterTest() override {}
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostTestSubmitFrameResources);
 
 }  // namespace
 }  // namespace cc