cc: Implement shared worker contexts. (v1)

content/browser/compositor/gpu_process_transport_factory.cc

 // Copyright 2014 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 "content/browser/compositor/gpu_process_transport_factory.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 247 matching lines @@
       if (context_provider && !context_provider->BindToCurrentThread())
         context_provider = nullptr;
       if (!shared_worker_context_provider_) {
         shared_worker_context_provider_ = ContextProviderCommandBuffer::Create(
             GpuProcessTransportFactory::CreateContextCommon(gpu_channel_host,
                                                             0),
             BROWSER_WORKER_CONTEXT);
         if (shared_worker_context_provider_ &&
             !shared_worker_context_provider_->BindToCurrentThread())
           shared_worker_context_provider_ = nullptr;
+
+        if (shared_worker_context_provider_) {
+          shared_worker_context_provider_->SetupLock();
+          // Detach from thread to allow context to be destroyed on a
+          // different thread without being used.
+          shared_worker_context_provider_->DetachFromThread();
+        }
       }
     }
 
     bool created_gpu_browser_compositor =
         !!context_provider && !!shared_worker_context_provider_;
 
     UMA_HISTOGRAM_BOOLEAN("Aura.CreatedGpuBrowserCompositor",
                           created_gpu_browser_compositor);
 
     if (!created_gpu_browser_compositor) {
@@ skipping 344 matching lines @@
   FOR_EACH_OBSERVER(ImageTransportFactoryObserver,
                     observer_list_,
                     OnLostResources());
 
   // Kill things that use the shared context before killing the shared context.
   lost_gl_helper.reset();
   lost_shared_main_thread_contexts  = NULL;
 }
 
 }  // namespace content