Defer compositor context creation to the thread.

cc/output/overlay_unittest.cc

Index: cc/output/overlay_unittest.cc
diff --git a/cc/output/overlay_unittest.cc b/cc/output/overlay_unittest.cc
index 3e9f5edeeb60aa87d55c85b19de03d379df53ded..52bc0ead68f2c78d7014fd5738634413b1bf32c2 100644
--- a/cc/output/overlay_unittest.cc
+++ b/cc/output/overlay_unittest.cc
@@ -133,8 +133,9 @@ size_t DefaultOverlayProcessor::GetStrategyCount() {
 
 class OverlayOutputSurface : public OutputSurface {
  public:
-  explicit OverlayOutputSurface(scoped_refptr<ContextProvider> context_provider)
-      : OutputSurface(context_provider) {
+  explicit OverlayOutputSurface(
+      std::unique_ptr<ContextProvider::DeferredCreate> context_provider_create)
+      : OutputSurface(std::move(context_provider_create)) {
     surface_size_ = kDisplaySize;
     device_scale_factor_ = 1;
     is_displayed_as_overlay_plane_ = true;
@@ -336,8 +337,8 @@ template <typename OverlayCandidateValidatorType>
 class OverlayTest : public testing::Test {
  protected:
   void SetUp() override {
-    provider_ = TestContextProvider::Create();
-    output_surface_.reset(new OverlayOutputSurface(provider_));
+    output_surface_.reset(new OverlayOutputSurface(
+        base::MakeUnique<TestContextProvider::DeferredCreate>()));
     EXPECT_TRUE(output_surface_->BindToClient(&client_));
     output_surface_->SetOverlayCandidateValidator(
         new OverlayCandidateValidatorType);
@@ -350,7 +351,6 @@ class OverlayTest : public testing::Test {
     overlay_processor_->Initialize();
   }
 
-  scoped_refptr<TestContextProvider> provider_;
   std::unique_ptr<OverlayOutputSurface> output_surface_;
   FakeOutputSurfaceClient client_;
   std::unique_ptr<SharedBitmapManager> shared_bitmap_manager_;
@@ -364,8 +364,8 @@ typedef OverlayTest<UnderlayOverlayValidator> UnderlayTest;
 typedef OverlayTest<CALayerValidator> CALayerOverlayTest;
 
 TEST(OverlayTest, NoOverlaysByDefault) {
-  scoped_refptr<TestContextProvider> provider = TestContextProvider::Create();
-  OverlayOutputSurface output_surface(provider);
+  OverlayOutputSurface output_surface(
+      base::MakeUnique<TestContextProvider::DeferredCreate>());
   EXPECT_EQ(NULL, output_surface.GetOverlayCandidateValidator());
 
   output_surface.SetOverlayCandidateValidator(new SingleOverlayValidator);
@@ -373,8 +373,8 @@ TEST(OverlayTest, NoOverlaysByDefault) {
 }
 
 TEST(OverlayTest, OverlaysProcessorHasStrategy) {
-  scoped_refptr<TestContextProvider> provider = TestContextProvider::Create();
-  OverlayOutputSurface output_surface(provider);
+  OverlayOutputSurface output_surface(
+      base::MakeUnique<TestContextProvider::DeferredCreate>());
   FakeOutputSurfaceClient client;
   EXPECT_TRUE(output_surface.BindToClient(&client));
   output_surface.SetOverlayCandidateValidator(new SingleOverlayValidator);
@@ -1203,8 +1203,10 @@ class MockOverlayScheduler {
 class GLRendererWithOverlaysTest : public testing::Test {
  protected:
   GLRendererWithOverlaysTest() {
-    provider_ = TestContextProvider::Create();
-    output_surface_.reset(new OverlayOutputSurface(provider_));
+    std::unique_ptr<TestContextProvider::DeferredCreate> context_create(
+        new TestContextProvider::DeferredCreate);
+    context_create->created_context = &provider_;

[piman, 2016/05/17 03:41:40]

I don't know, this feels a little twisted - I think I'd prefer a static_cast at
this point...

Another way is to invert the relationship - maybe have the
TestContextProvider::DeferredCreate own the TestContextSupport, and have it pass
it to the TestContextProvider?

[danakj, 2016/05/17 19:53:33]

After sleeping on it I'm thinking static cast also, for layer tree tests can do
it in InitializedRendererOnThread so it's pretty well defined.

+    output_surface_.reset(new OverlayOutputSurface(std::move(context_create)));
     CHECK(output_surface_->BindToClient(&output_surface_client_));
     resource_provider_ =
         FakeResourceProvider::Create(output_surface_.get(), nullptr);
@@ -1237,11 +1239,11 @@ class GLRendererWithOverlaysTest : public testing::Test {
 
   RendererSettings settings_;
   FakeOutputSurfaceClient output_surface_client_;
+  TestContextProvider* provider_ = nullptr;
   std::unique_ptr<OverlayOutputSurface> output_surface_;
   FakeRendererClient renderer_client_;
   std::unique_ptr<ResourceProvider> resource_provider_;
   std::unique_ptr<OverlayInfoRendererGL> renderer_;
-  scoped_refptr<TestContextProvider> provider_;
   MockOverlayScheduler scheduler_;
 };