Defer compositor context creation to the thread.

cc/output/output_surface.cc

Index: cc/output/output_surface.cc
diff --git a/cc/output/output_surface.cc b/cc/output/output_surface.cc
index 3e1549701e9ba6fdcedc4ed401fb66fd2e699105..f6f3168d5bcdcf5954c3aa93095391c6c2ece71d 100644
--- a/cc/output/output_surface.cc
+++ b/cc/output/output_surface.cc
@@ -119,12 +119,12 @@ class SkiaGpuTraceMemoryDump : public SkTraceMemoryDump {
 }  // namespace
 
 OutputSurface::OutputSurface(
-    scoped_refptr<ContextProvider> context_provider,
+    std::unique_ptr<ContextProvider::Factory> compositor_context_factory,
     scoped_refptr<ContextProvider> worker_context_provider,
     scoped_refptr<VulkanContextProvider> vulkan_context_provider,
     std::unique_ptr<SoftwareOutputDevice> software_device)
     : client_(NULL),
-      context_provider_(std::move(context_provider)),
+      compositor_context_factory_(std::move(compositor_context_factory)),
       worker_context_provider_(std::move(worker_context_provider)),
       vulkan_context_provider_(vulkan_context_provider),
       software_device_(std::move(software_device)),
@@ -135,21 +135,20 @@ OutputSurface::OutputSurface(
   client_thread_checker_.DetachFromThread();
 }
 
-OutputSurface::OutputSurface(scoped_refptr<ContextProvider> context_provider)
-    : OutputSurface(std::move(context_provider),
+OutputSurface::OutputSurface(
+    std::unique_ptr<ContextProvider::Factory> compositor_context_factory)
+    : OutputSurface(std::move(compositor_context_factory),
                     nullptr,
                     nullptr,
-                    nullptr) {
-}
+                    nullptr) {}
 
 OutputSurface::OutputSurface(
-    scoped_refptr<ContextProvider> context_provider,
+    std::unique_ptr<ContextProvider::Factory> compositor_context_factory,
     scoped_refptr<ContextProvider> worker_context_provider)
-    : OutputSurface(std::move(context_provider),
+    : OutputSurface(std::move(compositor_context_factory),
                     std::move(worker_context_provider),
                     nullptr,
-                    nullptr) {
-}
+                    nullptr) {}
 
 OutputSurface::OutputSurface(
     std::unique_ptr<SoftwareOutputDevice> software_device)
@@ -160,13 +159,12 @@ OutputSurface::OutputSurface(
 }
 
 OutputSurface::OutputSurface(
-    scoped_refptr<ContextProvider> context_provider,
+    std::unique_ptr<ContextProvider::Factory> compositor_context_factory,
     std::unique_ptr<SoftwareOutputDevice> software_device)
-    : OutputSurface(std::move(context_provider),
+    : OutputSurface(std::move(compositor_context_factory),
                     nullptr,
                     nullptr,
-                    std::move(software_device)) {
-}
+                    std::move(software_device)) {}
 
 // Forwarded to OutputSurfaceClient
 void OutputSurface::SetNeedsRedrawRect(const gfx::Rect& damage_rect) {
@@ -205,12 +203,15 @@ bool OutputSurface::BindToClient(OutputSurfaceClient* client) {
   client_ = client;
   bool success = true;
 
-  if (context_provider_.get()) {
-    success = context_provider_->BindToCurrentThread();
-    if (success) {
-      context_provider_->SetLostContextCallback(base::Bind(
+  if (compositor_context_factory_) {
+    compositor_context_provider_ = compositor_context_factory_->CreateContext();
+    if (compositor_context_provider_) {
+      compositor_context_provider_->SetLostContextCallback(base::Bind(
           &OutputSurface::DidLoseOutputSurface, base::Unretained(this)));
     }
+    success = !!compositor_context_provider_;
+    // Don't keep around the dead Factory.
+    compositor_context_factory_ = nullptr;
   }
 
   // In certain cases, ThreadTaskRunnerHandle isn't set (Android Webview).
@@ -239,8 +240,8 @@ void OutputSurface::EnsureBackbuffer() {
 }
 
 void OutputSurface::DiscardBackbuffer() {
-  if (context_provider_.get())
-    context_provider_->ContextGL()->DiscardBackbufferCHROMIUM();
+  if (compositor_context_provider_)
+    compositor_context_provider_->ContextGL()->DiscardBackbufferCHROMIUM();
   if (software_device_)
     software_device_->DiscardBackbuffer();
 }
@@ -255,17 +256,17 @@ void OutputSurface::Reshape(const gfx::Size& size,
   surface_size_ = size;
   device_scale_factor_ = scale_factor;
   has_alpha_ = has_alpha;
-  if (context_provider_.get()) {
-    context_provider_->ContextGL()->ResizeCHROMIUM(size.width(), size.height(),
-                                                   scale_factor, has_alpha);
+  if (compositor_context_provider_) {
+    compositor_context_provider_->ContextGL()->ResizeCHROMIUM(
+        size.width(), size.height(), scale_factor, has_alpha);
   }
   if (software_device_)
     software_device_->Resize(size, scale_factor);
 }
 
 void OutputSurface::BindFramebuffer() {
-  DCHECK(context_provider_.get());
-  context_provider_->ContextGL()->BindFramebuffer(GL_FRAMEBUFFER, 0);
+  DCHECK(compositor_context_provider_);
+  compositor_context_provider_->ContextGL()->BindFramebuffer(GL_FRAMEBUFFER, 0);
 }
 
 void OutputSurface::PostSwapBuffersComplete() {
@@ -357,11 +358,11 @@ void OutputSurface::DetachFromClientInternal() {
   base::trace_event::MemoryDumpManager::GetInstance()->UnregisterDumpProvider(
       this);
 
-  if (context_provider_.get()) {
-    context_provider_->SetLostContextCallback(
+  if (compositor_context_provider_) {
+    compositor_context_provider_->SetLostContextCallback(
         ContextProvider::LostContextCallback());
   }
-  context_provider_ = nullptr;
+  compositor_context_provider_ = nullptr;
   client_ = nullptr;
   weak_ptr_factory_.InvalidateWeakPtrs();
 }