cc: Move worker threads to content.

ui/compositor/compositor.cc

Index: ui/compositor/compositor.cc
diff --git a/ui/compositor/compositor.cc b/ui/compositor/compositor.cc
index f050a64e1a74dede9134fcfe075fd614dcd9841c..0731e73dc26cf700045b71883cf4ac51a16eb6a9 100644
--- a/ui/compositor/compositor.cc
+++ b/ui/compositor/compositor.cc
@@ -14,6 +14,7 @@
 #include "base/profiler/scoped_tracker.h"
 #include "base/strings/string_util.h"
 #include "base/sys_info.h"
+#include "base/threading/simple_thread.h"
 #include "base/trace_event/trace_event.h"
 #include "cc/base/switches.h"
 #include "cc/input/input_handler.h"
@@ -21,6 +22,7 @@
 #include "cc/output/begin_frame_args.h"
 #include "cc/output/context_provider.h"
 #include "cc/output/latency_info_swap_promise.h"
+#include "cc/resources/task_graph_runner.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "cc/surfaces/surface_id_allocator.h"
 #include "cc/trees/layer_tree_host.h"
@@ -37,6 +39,21 @@
 
 namespace {
 
+class RasterThread : public base::SimpleThread {
+ public:
+  RasterThread(cc::TaskGraphRunner* task_graph_runner)
+      : base::SimpleThread("UICompositorWorker"),
+        task_graph_runner_(task_graph_runner) {}
+
+  // Overridden from base::SimpleThread:
+  void Run() override { task_graph_runner_->Run(); }
+
+ private:
+  cc::TaskGraphRunner* task_graph_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(RasterThread);
+};
+
 const double kDefaultRefreshRate = 60.0;
 const double kTestRefreshRate = 200.0;
 
@@ -75,6 +92,8 @@ Compositor::Compositor(gfx::AcceleratedWidget widget,
       widget_(widget),
       surface_id_allocator_(context_factory->CreateSurfaceIdAllocator()),
       task_runner_(task_runner),
+      task_graph_runner_(new cc::TaskGraphRunner),
+      raster_thread_(new RasterThread(task_graph_runner_.get())),

[piman, 2015/03/20 06:28:35]

We wouldn't want one raster thread per compositor.... We have one compositor per
window.

I think this should go onto the ui::ContextFactory (GpuProcessTransportFactory
in content/ for prod, ui::InProcessContextFactory for tests).

Also, we probably don't want to create the thread if
!IsUIImplSidePaintingEnabled()

[reveman, 2015/03/20 07:42:02]

Makes sense. Done.

       vsync_manager_(new CompositorVSyncManager()),
       device_scale_factor_(0.0f),
       last_started_frame_(0),
@@ -135,11 +154,13 @@ Compositor::Compositor(gfx::AcceleratedWidget widget,
   settings.use_one_copy = IsUIOneCopyEnabled();
   settings.use_image_texture_target = context_factory_->GetImageTextureTarget();
 
+  raster_thread_->Start();
+
   base::TimeTicks before_create = base::TimeTicks::Now();
   host_ = cc::LayerTreeHost::CreateSingleThreaded(
       this, this, context_factory_->GetSharedBitmapManager(),
-      context_factory_->GetGpuMemoryBufferManager(), settings, task_runner_,
-      nullptr);
+      context_factory_->GetGpuMemoryBufferManager(), task_graph_runner_.get(),
+      settings, task_runner_, nullptr);
   UMA_HISTOGRAM_TIMES("GPU.CreateBrowserCompositor",
                       base::TimeTicks::Now() - before_create);
   host_->SetRootLayer(root_web_layer_);
@@ -163,6 +184,9 @@ Compositor::~Compositor() {
   // down any contexts that the |host_| may rely upon.
   host_.reset();
 
+  task_graph_runner_->Shutdown();
+  raster_thread_->Join();
+
   context_factory_->RemoveCompositor(this);
 }