viz: Start the sampling profiler for oop-d thread.

Start the sampling profiler on the oop-d thread. Plumb the task-runner
of the compositor thread from viz through content to chrome, which
starts the profiler on the thread.

BUG=788808

Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel
Change-Id: Id9e05bc290205ad2d397028313b6e1a2430a9d92
Reviewed-on: https://chromium-review.googlesource.com/943401Reviewed-by: Antoine Labour <piman@chromium.org>
Reviewed-by: Mike Wittman <wittman@chromium.org>
Commit-Queue: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#540396}

chrome/gpu/chrome_content_gpu_client.cc

@@ -80,6 +80,14 @@ void ChromeContentGpuClient::PostIOThreadCreated(
                                 metrics::CallStackProfileParams::IO_THREAD));
 }
 
+void ChromeContentGpuClient::PostCompositorThreadCreated(
+    base::SingleThreadTaskRunner* task_runner) {
+  task_runner->PostTask(
+      FROM_HERE,
+      base::BindOnce(&ThreadProfiler::StartOnChildThread,
+                     metrics::CallStackProfileParams::COMPOSITOR_THREAD));
+}
+
 #if BUILDFLAG(ENABLE_LIBRARY_CDMS)
 std::unique_ptr<media::CdmProxy> ChromeContentGpuClient::CreateCdmProxy(
     const std::string& cdm_guid) {

chrome/gpu/chrome_content_gpu_client.h

@@ -35,6 +35,8 @@ class ChromeContentGpuClient : public content::ContentGpuClient {
       const gpu::GpuPreferences& gpu_preferences) override;
   void PostIOThreadCreated(
       base::SingleThreadTaskRunner* io_task_runner) override;
+  void PostCompositorThreadCreated(
+      base::SingleThreadTaskRunner* task_runner) override;
 
 #if BUILDFLAG(ENABLE_LIBRARY_CDMS)
   std::unique_ptr<media::CdmProxy> CreateCdmProxy(

components/viz/service/main/viz_main_impl.cc

@@ -133,6 +133,9 @@ VizMainImpl::VizMainImpl(Delegate* delegate,
   if (dependencies_.create_display_compositor) {
     compositor_thread_ = CreateAndStartCompositorThread();
     compositor_thread_task_runner_ = compositor_thread_->task_runner();
+    if (delegate_)
+      delegate_->PostCompositorThreadCreated(
+          compositor_thread_task_runner_.get());
   }
 
   CreateUkmRecorderIfNeeded(dependencies.connector);

components/viz/service/main/viz_main_impl.h

@@ -48,6 +48,8 @@ class VizMainImpl : public gpu::GpuSandboxHelper, public mojom::VizMain {
 
     virtual void OnInitializationFailed() = 0;
     virtual void OnGpuServiceConnection(GpuServiceImpl* gpu_service) = 0;
+    virtual void PostCompositorThreadCreated(
+        base::SingleThreadTaskRunner* task_runner) = 0;
   };
 
   struct ExternalDependencies {

content/gpu/gpu_child_thread.cc

@@ -285,6 +285,13 @@ void GpuChildThread::OnGpuServiceConnection(viz::GpuServiceImpl* gpu_service) {
   release_pending_requests_closure_.Run();
 }
 
+void GpuChildThread::PostCompositorThreadCreated(
+    base::SingleThreadTaskRunner* task_runner) {
+  auto* gpu_client = GetContentClient()->gpu();
+  if (gpu_client)
+    gpu_client->PostCompositorThreadCreated(task_runner);
+}
+
 void GpuChildThread::BindServiceFactoryRequest(
     service_manager::mojom::ServiceFactoryRequest request) {
   DVLOG(1) << "GPU: Binding service_manager::mojom::ServiceFactoryRequest";

content/gpu/gpu_child_thread.h

@@ -77,6 +77,8 @@ class GpuChildThread : public ChildThreadImpl,
   // viz::VizMainImpl::Delegate:
   void OnInitializationFailed() override;
   void OnGpuServiceConnection(viz::GpuServiceImpl* gpu_service) override;
+  void PostCompositorThreadCreated(
+      base::SingleThreadTaskRunner* task_runner) override;
 
   void BindServiceFactoryRequest(
       service_manager::mojom::ServiceFactoryRequest request);

content/public/gpu/content_gpu_client.h

@@ -42,9 +42,11 @@ class CONTENT_EXPORT ContentGpuClient {
   virtual void GpuServiceInitialized(
       const gpu::GpuPreferences& gpu_preferences) {}
 
-  // Called right after the IO thread is created.
+  // Called right after the IO/compositor thread is created.
   virtual void PostIOThreadCreated(
       base::SingleThreadTaskRunner* io_task_runner) {}
+  virtual void PostCompositorThreadCreated(
+      base::SingleThreadTaskRunner* task_runner) {}
 
   // Allows client to supply a SyncPointManager instance instead of having
   // content internally create one.