Re-land: cc: Implement shared worker contexts.

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 99 matching lines @@
     const scoped_refptr<ContextProvider>& context_provider,
     const scoped_refptr<ContextProvider>& worker_context_provider,
     scoped_ptr<SoftwareOutputDevice> software_device)
     : client_(NULL),
       context_provider_(context_provider),
       worker_context_provider_(worker_context_provider),
       software_device_(software_device.Pass()),
       device_scale_factor_(-1),
       external_stencil_test_enabled_(false),
       weak_ptr_factory_(this) {
+  client_thread_checker_.DetachFromThread();
 }
 
 OutputSurface::OutputSurface(
     const scoped_refptr<ContextProvider>& context_provider)
     : OutputSurface(context_provider, nullptr, nullptr) {
 }
 
 OutputSurface::OutputSurface(
     const scoped_refptr<ContextProvider>& context_provider,
     const scoped_refptr<ContextProvider>& worker_context_provider)
@@ skipping 54 matching lines @@
                                       transform_for_tile_priority,
                                       resourceless_software_draw);
 }
 
 OutputSurface::~OutputSurface() {
   // Unregister any dump provider. Safe to call (no-op) if we have not yet
   // registered.
   base::trace_event::MemoryDumpManager::GetInstance()->UnregisterDumpProvider(
       this);
 
-  if (context_provider_.get()) {
-    context_provider_->SetLostContextCallback(
-        ContextProvider::LostContextCallback());
-    context_provider_->SetMemoryPolicyChangedCallback(
-        ContextProvider::MemoryPolicyChangedCallback());
-  }
+  if (client_)
+    DetachFromClient();
 }
 
 bool OutputSurface::HasExternalStencilTest() const {
   return external_stencil_test_enabled_;
 }
 
 bool OutputSurface::BindToClient(OutputSurfaceClient* client) {
+  DCHECK(client_thread_checker_.CalledOnValidThread());
   DCHECK(client);
+  DCHECK(!client_);
   client_ = client;
   bool success = true;
 
   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;
 
   // In certain cases, ThreadTaskRunnerHandle isn't set (Android Webview).
   // Don't register a dump provider in these cases.
   // TODO(ericrk): Get this working in Android Webview. crbug.com/517156
   if (base::ThreadTaskRunnerHandle::IsSet()) {
     // Now that we are on the context thread, register a dump provider with this
     // thread's task runner. This will overwrite any previous dump provider
     // registered.
     base::trace_event::MemoryDumpManager::GetInstance()->RegisterDumpProvider(
         this, base::ThreadTaskRunnerHandle::Get());
   }
 
   return success;
 }
 
+void OutputSurface::DetachFromClient() {
+  DCHECK(client_thread_checker_.CalledOnValidThread());
+  DCHECK(client_);
+  if (context_provider_.get()) {
+    context_provider_->SetLostContextCallback(
+        ContextProvider::LostContextCallback());
+    context_provider_->SetMemoryPolicyChangedCallback(
+        ContextProvider::MemoryPolicyChangedCallback());
+  }
+  context_provider_ = nullptr;
+  client_ = nullptr;
+  weak_ptr_factory_.InvalidateWeakPtrs();
+}
+
 void OutputSurface::EnsureBackbuffer() {
   if (software_device_)
     software_device_->EnsureBackbuffer();
 }
 
 void OutputSurface::DiscardBackbuffer() {
   if (context_provider_.get())
     context_provider_->ContextGL()->DiscardBackbufferCHROMIUM();
   if (software_device_)
     software_device_->DiscardBackbuffer();
@@ skipping 86 matching lines @@
     if (auto* gr_context = context_provider->GrContext()) {
       SkiaGpuTraceMemoryDump trace_memory_dump(pmd);
       gr_context->dumpMemoryStatistics(&trace_memory_dump);
     }
   }
 
   return true;
 }
 
 }  // namespace cc