cc: Move worker threads to content.

content/browser/renderer_host/compositor_impl_android.cc

Index: content/browser/renderer_host/compositor_impl_android.cc
diff --git a/content/browser/renderer_host/compositor_impl_android.cc b/content/browser/renderer_host/compositor_impl_android.cc
index 010f8e2484e4810516adbf94a21dc1fcd34c3051..33e5b5ce68eeeb8a3332bdad4bb72b3064a3105d 100644
--- a/content/browser/renderer_host/compositor_impl_android.cc
+++ b/content/browser/renderer_host/compositor_impl_android.cc
@@ -18,6 +18,7 @@
 #include "base/memory/weak_ptr.h"
 #include "base/single_thread_task_runner.h"
 #include "base/synchronization/lock.h"
+#include "base/threading/simple_thread.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_checker.h"
 #include "cc/base/switches.h"
@@ -27,6 +28,7 @@
 #include "cc/output/context_provider.h"
 #include "cc/output/output_surface.h"
 #include "cc/output/output_surface_client.h"
+#include "cc/resources/task_graph_runner.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "cc/surfaces/onscreen_display_client.h"
 #include "cc/surfaces/surface_display_output_surface.h"
@@ -137,6 +139,29 @@ base::LazyInstance<cc::SurfaceManager> g_surface_manager =
 
 int g_surface_id_namespace = 0;
 
+class SingleThreadTaskGraphRunner
+    : public cc::TaskGraphRunner,
+      public base::DelegateSimpleThread::Delegate {
+ public:
+  SingleThreadTaskGraphRunner() : worker_thread_(this, "CompositorWorker") {
+    worker_thread_.Start();
+  }
+
+  ~SingleThreadTaskGraphRunner() override {
+    Shutdown();
+    worker_thread_.Join();
+  }
+
+ private:
+  // Overridden from base::DelegateSimpleThread::Delegate:
+  void Run() override { cc::TaskGraphRunner::Run(); }
+
+  base::DelegateSimpleThread worker_thread_;
+};
+
+base::LazyInstance<SingleThreadTaskGraphRunner> g_task_graph_runner =
+    LAZY_INSTANCE_INITIALIZER;
+
 } // anonymous namespace
 
 // static
@@ -395,13 +420,9 @@ void CompositorImpl::CreateLayerTreeHost() {
   settings.single_thread_proxy_scheduler = false;
 
   host_ = cc::LayerTreeHost::CreateSingleThreaded(
-      this,
-      this,
-      HostSharedBitmapManager::current(),
-      BrowserGpuMemoryBufferManager::current(),
-      settings,
-      base::MessageLoopProxy::current(),
-      nullptr);
+      this, this, HostSharedBitmapManager::current(),
+      BrowserGpuMemoryBufferManager::current(), g_task_graph_runner.Pointer(),
+      settings, base::MessageLoopProxy::current(), nullptr);
   host_->SetRootLayer(root_layer_);
 
   host_->SetVisible(true);