cc: Implement shared worker contexts. (v1)

cc/output/output_surface.cc

 // Copyright (c) 2013 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/output/output_surface.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "base/thread_task_runner_handle.h"
@@ skipping 110 matching lines @@
   if (context_provider_.get()) {
     success = context_provider_->BindToCurrentThread();
     if (success) {
       context_provider_->SetLostContextCallback(base::Bind(
           &OutputSurface::DidLoseOutputSurface, base::Unretained(this)));
       context_provider_->SetMemoryPolicyChangedCallback(
           base::Bind(&OutputSurface::SetMemoryPolicy, base::Unretained(this)));
     }
   }
 
-  if (success && worker_context_provider_.get()) {
-    success = worker_context_provider_->BindToCurrentThread();
-    if (success)
-      worker_context_provider_->SetupLock();
-  }
-
   if (!success)
     client_ = NULL;
 
   return success;
 }
 
 void OutputSurface::EnsureBackbuffer() {
   if (software_device_)
     software_device_->EnsureBackbuffer();
 }
@@ skipping 55 matching lines @@
 }
 
 void OutputSurface::SetWorkerContextShouldAggressivelyFreeResources(
     bool aggressively_free_resources) {
   TRACE_EVENT1("cc",
                "OutputSurface::SetWorkerContextShouldAggressivelyFreeResources",
                "aggressively_free_resources", aggressively_free_resources);
   if (auto* context_provider = worker_context_provider()) {
     ContextProvider::ScopedContextLock scoped_context(context_provider);
 
-    if (aggressively_free_resources) {
-      context_provider->DeleteCachedResources();
-    }
+    if (!context_provider->HasBeenDestroyed()) {
+      if (aggressively_free_resources) {
+        context_provider->DeleteCachedResources();
+      }
 
-    if (auto* context_support = context_provider->ContextSupport()) {
-      context_support->SetAggressivelyFreeResources(
-          aggressively_free_resources);
+      if (auto* context_support = context_provider->ContextSupport()) {
+        context_support->SetAggressivelyFreeResources(
+            aggressively_free_resources);
+      }
     }
   }
 }
 
 bool OutputSurface::SurfaceIsSuspendForRecycle() const {
   return false;
 }
 
 }  // namespace cc