cc: Route offscreen context creation for compositor to the browser.

cc/layer_tree_host_unittest_context.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layer_tree_host.h"
 
 #include "base/basictypes.h"
 #include "cc/content_layer.h"
 #include "cc/delegated_renderer_layer.h"
 #include "cc/delegated_renderer_layer_impl.h"
 #include "cc/heads_up_display_layer.h"
 #include "cc/io_surface_layer.h"
 #include "cc/layer_impl.h"
 #include "cc/layer_tree_host_impl.h"
 #include "cc/layer_tree_impl.h"
 #include "cc/picture_layer.h"
 #include "cc/scrollbar_layer.h"
 #include "cc/single_thread_proxy.h"
 #include "cc/test/fake_content_layer.h"
 #include "cc/test/fake_content_layer_client.h"
 #include "cc/test/fake_content_layer_impl.h"
+#include "cc/test/fake_context_provider.h"
 #include "cc/test/fake_output_surface.h"
 #include "cc/test/fake_scrollbar_layer.h"
 #include "cc/test/fake_scrollbar_theme_painter.h"
 #include "cc/test/fake_video_frame_provider.h"
 #include "cc/test/fake_web_scrollbar.h"
 #include "cc/test/fake_web_scrollbar_theme_geometry.h"
 #include "cc/test/layer_tree_test_common.h"
 #include "cc/test/render_pass_test_common.h"
 #include "cc/test/test_web_graphics_context_3d.h"
 #include "cc/texture_layer.h"
 #include "cc/video_layer.h"
 #include "cc/video_layer_impl.h"
 #include "gpu/GLES2/gl2extchromium.h"
 #include "media/base/media.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebFilterOperations.h"
 
 using media::VideoFrame;
 using WebKit::WebGraphicsContext3D;
 
 namespace cc {
 namespace {
 
 // These tests deal with losing the 3d graphics context.
 class LayerTreeHostContextTest : public ThreadedTest {
  public:
   LayerTreeHostContextTest()
       : ThreadedTest(),
         context3d_(NULL),
         times_to_fail_create_(0),
         times_to_fail_initialize_(0),
         times_to_lose_on_create_(0),
         times_to_lose_during_commit_(0),
         times_to_lose_during_draw_(0),
         times_to_fail_recreate_(0),
         times_to_fail_reinitialize_(0),
-        times_to_lose_on_recreate_(0) {
+        times_to_lose_on_recreate_(0),
+        times_to_fail_create_offscreen_(0),
+        times_to_fail_recreate_offscreen_(0),
+        times_to_expect_recreate_retried_(0),
+        times_recreate_retried_(0),
+        times_offscreen_created_(0),
+        committed_at_least_once_(false) {
     media::InitializeMediaLibraryForTesting();
   }
 
   void LoseContext() {
     context3d_->loseContextCHROMIUM(GL_GUILTY_CONTEXT_RESET_ARB,
                                     GL_INNOCENT_CONTEXT_RESET_ARB);
     context3d_ = NULL;
   }
 
   virtual scoped_ptr<TestWebGraphicsContext3D> CreateContext3d() {
     return TestWebGraphicsContext3D::Create();
   }
 
   virtual scoped_ptr<OutputSurface> createOutputSurface() OVERRIDE {
     if (times_to_fail_create_) {
       --times_to_fail_create_;
+      ExpectRecreateToRetry();
       return scoped_ptr<OutputSurface>();
     }
 
     scoped_ptr<TestWebGraphicsContext3D> context3d = CreateContext3d();
     context3d_ = context3d.get();
 
     if (times_to_fail_initialize_) {
       --times_to_fail_initialize_;
       // Make the context get lost during reinitialization.
       // The number of times MakeCurrent succeeds is not important, and
       // can be changed if needed to make this pass with future changes.
       context3d_->set_times_make_current_succeeds(2);
+      ExpectRecreateToRetry();
     } else if (times_to_lose_on_create_) {
       --times_to_lose_on_create_;
       LoseContext();
+      ExpectRecreateToRetry();
     }
 
     return FakeOutputSurface::Create3d(
         context3d.PassAs<WebGraphicsContext3D>()).PassAs<OutputSurface>();
   }
 
-    virtual bool prepareToDrawOnThread(
-        LayerTreeHostImpl*, LayerTreeHostImpl::FrameData&, bool result)
-        OVERRIDE {
-      EXPECT_TRUE(result);
-      if (!times_to_lose_during_draw_)
-        return result;
+  scoped_ptr<TestWebGraphicsContext3D> CreateOffscreenContext3d() {
+    if (!context3d_)
+      return scoped_ptr<TestWebGraphicsContext3D>();
 
-      --times_to_lose_during_draw_;
-      if (context3d_)
-        context3d_->set_times_make_current_succeeds(0);
-      return result;
+    ++times_offscreen_created_;
+
+    if (times_to_fail_create_offscreen_) {
+      --times_to_fail_create_offscreen_;
+      ExpectRecreateToRetry();
+      return scoped_ptr<TestWebGraphicsContext3D>();
     }
 
+    scoped_ptr<TestWebGraphicsContext3D> offscreen_context3d =
+        TestWebGraphicsContext3D::Create().Pass();
+    DCHECK(offscreen_context3d);
+    context3d_->add_share_group_context(offscreen_context3d.get());
+
+    return offscreen_context3d.Pass();
+  }
+
+  virtual scoped_refptr<cc::ContextProvider>
+  OffscreenContextProviderForMainThread() OVERRIDE {
+    DCHECK(!implThread());
+
+    if (!offscreen_contexts_main_thread_ ||
+        offscreen_contexts_main_thread_->DestroyedOnMainThread()) {
+      offscreen_contexts_main_thread_ = new FakeContextProvider(
+          base::Bind(&LayerTreeHostContextTest::CreateOffscreenContext3d,
+                     base::Unretained(this)));
+    }
+    return offscreen_contexts_main_thread_;
+  }
+
+  virtual scoped_refptr<cc::ContextProvider>
+  OffscreenContextProviderForCompositorThread() OVERRIDE {
+    DCHECK(implThread());
+
+    if (!offscreen_contexts_compositor_thread_ ||
+        offscreen_contexts_compositor_thread_->DestroyedOnMainThread()) {
+      offscreen_contexts_compositor_thread_ = new FakeContextProvider(
+          base::Bind(&LayerTreeHostContextTest::CreateOffscreenContext3d,
+                     base::Unretained(this)));
+    }
+    return offscreen_contexts_compositor_thread_;
+  }
+
+  virtual bool prepareToDrawOnThread(
+      LayerTreeHostImpl*, LayerTreeHostImpl::FrameData&, bool result)
+      OVERRIDE {
+    EXPECT_TRUE(result);
+    if (!times_to_lose_during_draw_)
+      return result;
+
+    --times_to_lose_during_draw_;
+    context3d_->set_times_make_current_succeeds(0);
+
+    times_to_fail_create_ = times_to_fail_recreate_;
+    times_to_fail_recreate_ = 0;
+    times_to_fail_initialize_ = times_to_fail_reinitialize_;
+    times_to_fail_reinitialize_ = 0;
+    times_to_lose_on_create_ = times_to_lose_on_recreate_;
+    times_to_lose_on_recreate_ = 0;
+    times_to_fail_create_offscreen_ = times_to_fail_recreate_offscreen_;
+    times_to_fail_recreate_offscreen_ = 0;
+
+    return result;
+  }
+
   virtual void commitCompleteOnThread(LayerTreeHostImpl *host_impl) OVERRIDE {
+    committed_at_least_once_ = true;
+
     if (!times_to_lose_during_commit_)
       return;
     --times_to_lose_during_commit_;
     LoseContext();
 
     times_to_fail_create_ = times_to_fail_recreate_;
     times_to_fail_recreate_ = 0;
     times_to_fail_initialize_ = times_to_fail_reinitialize_;
     times_to_fail_reinitialize_ = 0;
     times_to_lose_on_create_ = times_to_lose_on_recreate_;
     times_to_lose_on_recreate_ = 0;
+    times_to_fail_create_offscreen_ = times_to_fail_recreate_offscreen_;
+    times_to_fail_recreate_offscreen_ = 0;
+  }
+
+  virtual void willRetryRecreateOutputSurface() OVERRIDE {
+    ++times_recreate_retried_;
+  }
+
+  virtual void TearDown() OVERRIDE {
+    ThreadedTest::TearDown();
+    EXPECT_EQ(times_to_expect_recreate_retried_, times_recreate_retried_);
+  }
+
+  void ExpectRecreateToRetry() {
+    if (committed_at_least_once_)
+      ++times_to_expect_recreate_retried_;
   }
 
  protected:
   TestWebGraphicsContext3D* context3d_;
   int times_to_fail_create_;
   int times_to_fail_initialize_;
   int times_to_lose_on_create_;
   int times_to_lose_during_commit_;
   int times_to_lose_during_draw_;
   int times_to_fail_reinitialize_;
   int times_to_fail_recreate_;
   int times_to_lose_on_recreate_;
+  int times_to_fail_create_offscreen_;
+  int times_to_fail_recreate_offscreen_;
+  int times_to_expect_recreate_retried_;
+  int times_recreate_retried_;
+  int times_offscreen_created_;
+  bool committed_at_least_once_;
+
+  scoped_refptr<FakeContextProvider> offscreen_contexts_main_thread_;
+  scoped_refptr<FakeContextProvider> offscreen_contexts_compositor_thread_;
 };
 
 class LayerTreeHostContextTestLostContextSucceeds :
       public LayerTreeHostContextTest {
  public:
   LayerTreeHostContextTestLostContextSucceeds()
       : LayerTreeHostContextTest(),
         test_case_(0),
         num_losses_(0),
         recovered_context_(true) {
   }
 
   virtual void beginTest() OVERRIDE {
     postSetNeedsCommitToMainThread();
   }
 
   virtual void didRecreateOutputSurface(bool succeeded) OVERRIDE {
     EXPECT_TRUE(succeeded);
     ++num_losses_;
     recovered_context_ = true;
   }
 
   virtual void afterTest() OVERRIDE {
-    EXPECT_EQ(8, test_case_);
-    EXPECT_EQ(6 + 10 + 10, num_losses_);
+    EXPECT_EQ(10, test_case_);
+    EXPECT_EQ(8 + 10 + 10, num_losses_);
   }
 
   virtual void didCommitAndDrawFrame() OVERRIDE {
     // If the last frame had a context loss, then we'll commit again to
     // recover.
     if (!recovered_context_)
       return;
     if (times_to_lose_during_commit_)
       return;
     if (times_to_lose_during_draw_)
@@ skipping 12 matching lines @@
 
   bool NextTestCase() {
     static const TestCase kTests[] = {
       // Losing the context and failing to recreate it (or losing it again
       // immediately) a small number of times should succeed.
       { 1, // times_to_lose_during_commit
         0, // times_to_lose_during_draw
         3, // times_to_fail_reinitialize
         0, // times_to_fail_recreate
         0, // times_to_lose_on_recreate
+        0, // times_to_fail_recreate_offscreen
       },
       { 0, // times_to_lose_during_commit
         1, // times_to_lose_during_draw
         3, // times_to_fail_reinitialize
         0, // times_to_fail_recreate
         0, // times_to_lose_on_recreate
+        0, // times_to_fail_recreate_offscreen
       },
       { 1, // times_to_lose_during_commit
         0, // times_to_lose_during_draw
         0, // times_to_fail_reinitialize
         3, // times_to_fail_recreate
         0, // times_to_lose_on_recreate
+        0, // times_to_fail_recreate_offscreen
       },
       { 0, // times_to_lose_during_commit
         1, // times_to_lose_during_draw
         0, // times_to_fail_reinitialize
         3, // times_to_fail_recreate
         0, // times_to_lose_on_recreate
+        0, // times_to_fail_recreate_offscreen
       },
       { 1, // times_to_lose_during_commit
         0, // times_to_lose_during_draw
         0, // times_to_fail_reinitialize
         0, // times_to_fail_recreate
         3, // times_to_lose_on_recreate
+        0, // times_to_fail_recreate_offscreen
       },
       { 0, // times_to_lose_during_commit
         1, // times_to_lose_during_draw
         0, // times_to_fail_reinitialize
         0, // times_to_fail_recreate
         3, // times_to_lose_on_recreate
+        0, // times_to_fail_recreate_offscreen
+      },
+      { 1, // times_to_lose_during_commit
+        0, // times_to_lose_during_draw
+        0, // times_to_fail_reinitialize
+        0, // times_to_fail_recreate
+        0, // times_to_lose_on_recreate
+        3, // times_to_fail_recreate_offscreen
+      },
+      { 0, // times_to_lose_during_commit
+        1, // times_to_lose_during_draw
+        0, // times_to_fail_reinitialize
+        0, // times_to_fail_recreate
+        0, // times_to_lose_on_recreate
+        3, // times_to_fail_recreate_offscreen
       },
       // Losing the context and recreating it any number of times should
       // succeed.
       { 10, // times_to_lose_during_commit
         0, // times_to_lose_during_draw
         0, // times_to_fail_reinitialize
         0, // times_to_fail_recreate
         0, // times_to_lose_on_recreate
+        0, // times_to_fail_recreate_offscreen
       },
       { 0, // times_to_lose_during_commit
         10, // times_to_lose_during_draw
         0, // times_to_fail_reinitialize
         0, // times_to_fail_recreate
         0, // times_to_lose_on_recreate
+        0, // times_to_fail_recreate_offscreen
       },
     };
 
     if (test_case_ >= arraysize(kTests))
       return false;
 
     times_to_lose_during_commit_ =
         kTests[test_case_].times_to_lose_during_commit;
     times_to_lose_during_draw_ =
         kTests[test_case_].times_to_lose_during_draw;
     times_to_fail_reinitialize_ = kTests[test_case_].times_to_fail_reinitialize;
     times_to_fail_recreate_ = kTests[test_case_].times_to_fail_recreate;
     times_to_lose_on_recreate_ = kTests[test_case_].times_to_lose_on_recreate;
+    times_to_fail_recreate_offscreen_ =
+        kTests[test_case_].times_to_fail_recreate_offscreen;
     ++test_case_;
     return true;
   }
 
   struct TestCase {
     int times_to_lose_during_commit;
     int times_to_lose_during_draw;
     int times_to_fail_reinitialize;
     int times_to_fail_recreate;
     int times_to_lose_on_recreate;
+    int times_to_fail_recreate_offscreen;
   };
 
- private:
+ protected:
   size_t test_case_;
   int num_losses_;
   bool recovered_context_;
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostContextTestLostContextSucceeds)
 
 class LayerTreeHostContextTestLostContextSucceedsWithContent :
     public LayerTreeHostContextTestLostContextSucceeds {
  public:
 
   LayerTreeHostContextTestLostContextSucceedsWithContent()
       : LayerTreeHostContextTestLostContextSucceeds() {
   }
 
   virtual void setupTree() OVERRIDE {
     root_ = Layer::create();
     root_->setBounds(gfx::Size(10, 10));
     root_->setAnchorPoint(gfx::PointF());
     root_->setIsDrawable(true);
 
     content_ = FakeContentLayer::Create(&client_);
     content_->setBounds(gfx::Size(10, 10));
     content_->setAnchorPoint(gfx::PointF());
     content_->setIsDrawable(true);
     if (use_surface_) {
-      // TODO(danakj): Give the surface a filter to test more code when we can
-      // do so without crashing in the shared context creation.
       content_->setForceRenderSurface(true);
+      // Filters require us to create an offscreen context.
+      WebKit::WebFilterOperations filters;
+      filters.append(WebKit::WebFilterOperation::createGrayscaleFilter(0.5f));
+      content_->setFilters(filters);
+      content_->setBackgroundFilters(filters);
     }
 
     root_->addChild(content_);
 
     m_layerTreeHost->setRootLayer(root_);
     LayerTreeHostContextTest::setupTree();
   }
 
   virtual void InvalidateAndSetNeedsCommit() OVERRIDE {
     // Invalidate the render surface so we don't try to use a cached copy of the
     // surface.  We want to make sure to test the drawing paths for drawing to
     // a child surface.
     content_->setNeedsDisplay();
     LayerTreeHostContextTestLostContextSucceeds::InvalidateAndSetNeedsCommit();
   }
 
   virtual void drawLayersOnThread(LayerTreeHostImpl* host_impl) OVERRIDE {
     FakeContentLayerImpl* content_impl = static_cast<FakeContentLayerImpl*>(
         host_impl->rootLayer()->children()[0]);
     // Even though the context was lost, we should have a resource. The
     // TestWebGraphicsContext3D ensures that this resource is created with
     // the active context.
     EXPECT_TRUE(content_impl->HaveResourceForTileAt(0, 0));
+
+    cc::ContextProvider* contexts =
+        host_impl->resourceProvider()->offscreenContextProvider();
+    if (use_surface_) {
+      EXPECT_TRUE(contexts->Context3d());
+      // TODO(danakj): Make a fake GrContext.
+      //EXPECT_TRUE(contexts->GrContext());
+    } else {
+      EXPECT_FALSE(contexts);
+    }
+  }
+
+  virtual void afterTest() OVERRIDE {
+    LayerTreeHostContextTestLostContextSucceeds::afterTest();
+    if (use_surface_) {
+      // 1 create to start with +
+      // 6 from test cases that fail on initializing the renderer (after the
+      // offscreen context is created) +
+      // 6 from test cases that lose the offscreen context directly +
+      // All the test cases that recreate both contexts only once
+      // per time it is lost.
+      EXPECT_EQ(6 + 6 + 1 + num_losses_, times_offscreen_created_);
+    } else {
+      EXPECT_EQ(0, times_offscreen_created_);
+    }
   }
 
  protected:
   bool use_surface_;
   FakeContentLayerClient client_;
   scoped_refptr<Layer> root_;
   scoped_refptr<ContentLayer> content_;
 };
 
 TEST_F(LayerTreeHostContextTestLostContextSucceedsWithContent,
@@ skipping 13 matching lines @@
   use_surface_ = true;
   runTest(false);
 }
 
 TEST_F(LayerTreeHostContextTestLostContextSucceedsWithContent,
        WithSurface_MultiThread) {
   use_surface_ = true;
   runTest(true);
 }
 
+class LayerTreeHostContextTestOffscreenContextFails
+    : public LayerTreeHostContextTest {
+ public:
+  virtual void setupTree() OVERRIDE {
+    root_ = Layer::create();
+    root_->setBounds(gfx::Size(10, 10));
+    root_->setAnchorPoint(gfx::PointF());
+    root_->setIsDrawable(true);
+
+    content_ = FakeContentLayer::Create(&client_);
+    content_->setBounds(gfx::Size(10, 10));
+    content_->setAnchorPoint(gfx::PointF());
+    content_->setIsDrawable(true);
+    content_->setForceRenderSurface(true);
+    // Filters require us to create an offscreen context.
+    WebKit::WebFilterOperations filters;
+    filters.append(WebKit::WebFilterOperation::createGrayscaleFilter(0.5f));
+    content_->setFilters(filters);
+    content_->setBackgroundFilters(filters);
+
+    root_->addChild(content_);
+
+    m_layerTreeHost->setRootLayer(root_);
+    LayerTreeHostContextTest::setupTree();
+  }
+
+  virtual void beginTest() OVERRIDE {
+    times_to_fail_create_offscreen_ = 1;
+    postSetNeedsCommitToMainThread();
+  }
+
+  virtual void drawLayersOnThread(LayerTreeHostImpl* host_impl) OVERRIDE {
+    cc::ContextProvider* contexts =
+        host_impl->resourceProvider()->offscreenContextProvider();
+    EXPECT_FALSE(contexts);
+    endTest();
+  }
+
+  virtual void afterTest() OVERRIDE {}
+
+ protected:
+  FakeContentLayerClient client_;
+  scoped_refptr<Layer> root_;
+  scoped_refptr<ContentLayer> content_;
+};
+
+SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostContextTestOffscreenContextFails)
+
 class LayerTreeHostContextTestLostContextFails :
     public LayerTreeHostContextTest {
  public:
   LayerTreeHostContextTestLostContextFails()
       : LayerTreeHostContextTest(),
         num_commits_(0) {
     times_to_lose_during_commit_ = 1;
   }
 
   virtual void beginTest() OVERRIDE {
@@ skipping 133 matching lines @@
   }
 
   virtual void didCommitAndDrawFrame() OVERRIDE {
     if (num_commits_ > 1)
       return;
     EXPECT_TRUE(layer_->HaveBackingAt(0, 0));
     PostEvictTextures();
   }
 
   virtual void commitCompleteOnThread(LayerTreeHostImpl* impl) OVERRIDE {
+    LayerTreeHostContextTest::commitCompleteOnThread(impl);
     if (num_commits_ > 1)
       return;
     ++num_commits_;
     if (!lose_after_evict_)
       LoseContext();
     impl_host_ = impl;
   }
 
   virtual void didRecreateOutputSurface(bool succeeded) OVERRIDE {
     EXPECT_TRUE(succeeded);
@@ skipping 66 matching lines @@
 
     m_layerTreeHost->setRootLayer(parent_);
     LayerTreeHostContextTest::setupTree();
   }
 
   virtual void beginTest() OVERRIDE {
     postSetNeedsCommitToMainThread();
   }
 
   virtual void commitCompleteOnThread(LayerTreeHostImpl* impl) OVERRIDE {
+    LayerTreeHostContextTest::commitCompleteOnThread(impl);
     endTest();
   }
 
   virtual void didRecreateOutputSurface(bool succeeded) OVERRIDE {
     EXPECT_TRUE(succeeded);
   }
 
   virtual void afterTest() OVERRIDE {
     EXPECT_EQ(0, times_to_lose_on_end_query_);
   }
@@ skipping 26 matching lines @@
 
     m_layerTreeHost->setRootLayer(root_);
     LayerTreeHostContextTest::setupTree();
   }
 
   virtual void beginTest() OVERRIDE {
     postSetNeedsCommitToMainThread();
   }
 
   virtual void commitCompleteOnThread(LayerTreeHostImpl* host_impl) OVERRIDE {
+    LayerTreeHostContextTest::commitCompleteOnThread(host_impl);
+
     FakeContentLayerImpl* root = static_cast<FakeContentLayerImpl*>(
         host_impl->rootLayer());
     FakeContentLayerImpl* child = static_cast<FakeContentLayerImpl*>(
         root->children()[0]);
     FakeContentLayerImpl* grandchild = static_cast<FakeContentLayerImpl*>(
         child->children()[0]);
 
     ++num_commits_;
     switch (num_commits_) {
       case 1:
@@ skipping 142 matching lines @@
 
     m_layerTreeHost->setRootLayer(root_);
     LayerTreeHostContextTest::setupTree();
   }
 
   virtual void beginTest() OVERRIDE {
     postSetNeedsCommitToMainThread();
   }
 
   virtual void commitCompleteOnThread(LayerTreeHostImpl* host_impl) OVERRIDE {
+    LayerTreeHostContextTest::commitCompleteOnThread(host_impl);
+
     ResourceProvider* resource_provider = host_impl->resourceProvider();
 
     if (host_impl->activeTree()->source_frame_number() == 0) {
       // Set up impl resources on the first commit.
 
       scoped_ptr<TestRenderPass> pass_for_quad = TestRenderPass::Create();
       pass_for_quad->SetNew(
           // AppendOneOfEveryQuadType() makes a RenderPass quad with this id.
           RenderPass::Id(1, 1),
           gfx::Rect(0, 0, 10, 10),
@@ skipping 188 matching lines @@
     scrollbar_layer_->setBounds(gfx::Size(10, 100));
     m_layerTreeHost->rootLayer()->addChild(scrollbar_layer_);
     m_layerTreeHost->rootLayer()->addChild(scroll_layer);
     postSetNeedsCommitToMainThread();
   }
 
   virtual void afterTest() OVERRIDE {
   }
 
   virtual void commitCompleteOnThread(LayerTreeHostImpl* impl) OVERRIDE {
+    LayerTreeHostContextTest::commitCompleteOnThread(impl);
+
     ++commits_;
     size_t upload_count = scrollbar_layer_->last_update_full_upload_size() +
         scrollbar_layer_->last_update_partial_upload_size();
     switch(commits_) {
       case 1:
         // First (regular) update, we should upload 2 resources (thumb, and
         // backtrack).
         EXPECT_EQ(1, scrollbar_layer_->update_count());
         EXPECT_EQ(2, upload_count);
         LoseContext();
@@ skipping 12 matching lines @@
 
  private:
   int commits_;
   scoped_refptr<FakeScrollbarLayer> scrollbar_layer_;
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(ScrollbarLayerLostContext)
 
 }  // namespace
 }  // namespace cc