Revert "Make SingleThreadProxy a SchedulerClient"

This reverts commit r288866 because of crashes.
Old patch: https://codereview.chromium.org/134623005/

NOTRY=true
TBR=danakj@chromium.org,boliu@chromium.org,piman@chromium.org,ben@chromium.org
BUG=402943,403400

Review URL: https://codereview.chromium.org/475483002

Cr-Commit-Position: refs/heads/master@{#289395}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289395 0039d316-1c4b-4281-b951-d872f2087c98

42 files changed, 479 insertions, 665 deletions

diff --git a/android_webview/browser/hardware_renderer.cc b/android_webview/browser/hardware_renderer.cc
index d4c28b9..5fb527f 100644
--- a/android_webview/browser/hardware_renderer.cc
+++ b/android_webview/browser/hardware_renderer.cc
@@ -95,9 +95,6 @@ HardwareRenderer::HardwareRenderer(SharedRendererState* state)
   // Webview does not own the surface so should not clear it.
   settings.should_clear_root_render_pass = false;
 
-  // TODO(enne): Update this this compositor to use a synchronous scheduler.
-  settings.single_thread_proxy_scheduler = false;
-
   layer_tree_host_ =
       cc::LayerTreeHost::CreateSingleThreaded(this, this, NULL, settings, NULL);
   layer_tree_host_->SetRootLayer(root_layer_);
diff --git a/android_webview/browser/hardware_renderer.h b/android_webview/browser/hardware_renderer.h
index b07d36d..f87890b 100644
--- a/android_webview/browser/hardware_renderer.h
+++ b/android_webview/browser/hardware_renderer.h
@@ -54,6 +54,8 @@ class HardwareRenderer : public cc::LayerTreeHostClient,
   virtual void DidCompleteSwapBuffers() OVERRIDE {}
 
   // cc::LayerTreeHostSingleThreadClient overrides.
+  virtual void ScheduleComposite() OVERRIDE {}
+  virtual void ScheduleAnimation() OVERRIDE {}
   virtual void DidPostSwapBuffers() OVERRIDE {}
   virtual void DidAbortSwapBuffers() OVERRIDE {}
 
diff --git a/cc/BUILD.gn b/cc/BUILD.gn
index 7c1254a..ddabbdd 100644
--- a/cc/BUILD.gn
+++ b/cc/BUILD.gn
@@ -452,7 +452,6 @@ component("cc") {
     "trees/proxy.h",
     "trees/proxy_timing_history.cc",
     "trees/proxy_timing_history.h",
-    "trees/scoped_abort_remaining_swap_promises.h",
     "trees/single_thread_proxy.cc",
     "trees/single_thread_proxy.h",
     "trees/thread_proxy.cc",
diff --git a/cc/cc.gyp b/cc/cc.gyp
index 5bd14ec..eac03d7 100644
--- a/cc/cc.gyp
+++ b/cc/cc.gyp
@@ -481,7 +481,6 @@
         'trees/proxy.h',
         'trees/proxy_timing_history.cc',
         'trees/proxy_timing_history.h',
-        'trees/scoped_abort_remaining_swap_promises.h',
         'trees/single_thread_proxy.cc',
         'trees/single_thread_proxy.h',
         'trees/thread_proxy.cc',
diff --git a/cc/scheduler/scheduler.cc b/cc/scheduler/scheduler.cc
index a20bfd2b..1451237 100644
--- a/cc/scheduler/scheduler.cc
+++ b/cc/scheduler/scheduler.cc
@@ -79,11 +79,11 @@ Scheduler::Scheduler(
     SchedulerClient* client,
     const SchedulerSettings& scheduler_settings,
     int layer_tree_host_id,
-    const scoped_refptr<base::SingleThreadTaskRunner>& task_runner)
+    const scoped_refptr<base::SingleThreadTaskRunner>& impl_task_runner)
     : settings_(scheduler_settings),
       client_(client),
       layer_tree_host_id_(layer_tree_host_id),
-      task_runner_(task_runner),
+      impl_task_runner_(impl_task_runner),
       vsync_interval_(BeginFrameArgs::DefaultInterval()),
       last_set_needs_begin_frame_(false),
       begin_unthrottled_frame_posted_(false),
@@ -128,7 +128,7 @@ Scheduler::~Scheduler() {
 void Scheduler::SetupSyntheticBeginFrames() {
   DCHECK(!synthetic_begin_frame_source_);
   synthetic_begin_frame_source_.reset(
-      new SyntheticBeginFrameSource(this, task_runner_.get()));
+      new SyntheticBeginFrameSource(this, impl_task_runner_.get()));
 }
 
 void Scheduler::CommitVSyncParameters(base::TimeTicks timebase,
@@ -274,9 +274,6 @@ base::TimeTicks Scheduler::LastBeginImplFrameTime() {
 }
 
 void Scheduler::SetupNextBeginFrameIfNeeded() {
-  if (!task_runner_)
-    return;
-
   bool needs_begin_frame = state_machine_.BeginFrameNeeded();
 
   if (settings_.throttle_frame_production) {
@@ -331,7 +328,7 @@ void Scheduler::SetupNextBeginFrameWhenVSyncThrottlingDisabled(
   }
 
   begin_unthrottled_frame_posted_ = true;
-  task_runner_->PostTask(FROM_HERE, begin_unthrottled_frame_closure_);
+  impl_task_runner_->PostTask(FROM_HERE, begin_unthrottled_frame_closure_);
 }
 
 // BeginUnthrottledFrame is used when we aren't throttling frame production.
@@ -365,7 +362,7 @@ void Scheduler::SetupPollingMechanisms(bool needs_begin_frame) {
       base::TimeDelta delay = begin_impl_frame_args_.IsValid()
                                   ? begin_impl_frame_args_.interval
                                   : BeginFrameArgs::DefaultInterval();
-      task_runner_->PostDelayedTask(
+      impl_task_runner_->PostDelayedTask(
           FROM_HERE, poll_for_draw_triggers_task_.callback(), delay);
     }
   } else {
@@ -390,9 +387,9 @@ void Scheduler::SetupPollingMechanisms(bool needs_begin_frame) {
       // Since we'd rather get a BeginImplFrame by the normal mechanism, we
       // set the interval to twice the interval from the previous frame.
       advance_commit_state_task_.Reset(advance_commit_state_closure_);
-      task_runner_->PostDelayedTask(FROM_HERE,
-                                    advance_commit_state_task_.callback(),
-                                    begin_impl_frame_args_.interval * 2);
+      impl_task_runner_->PostDelayedTask(FROM_HERE,
+                                         advance_commit_state_task_.callback(),
+                                         begin_impl_frame_args_.interval * 2);
     }
   } else {
     advance_commit_state_task_.Cancel();
@@ -494,7 +491,7 @@ void Scheduler::PostBeginRetroFrameIfNeeded() {
     return;
 
   begin_retro_frame_posted_ = true;
-  task_runner_->PostTask(FROM_HERE, begin_retro_frame_closure_);
+  impl_task_runner_->PostTask(FROM_HERE, begin_retro_frame_closure_);
 }
 
 // BeginImplFrame starts a compositor frame that will wait up until a deadline
@@ -502,8 +499,8 @@ void Scheduler::PostBeginRetroFrameIfNeeded() {
 // any asynchronous animation and scroll/pinch updates.
 void Scheduler::BeginImplFrame(const BeginFrameArgs& args) {
   TRACE_EVENT1("cc", "Scheduler::BeginImplFrame", "args", args.AsValue());
-  DCHECK_EQ(state_machine_.begin_impl_frame_state(),
-            SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE);
+  DCHECK(state_machine_.begin_impl_frame_state() ==
+         SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE);
   DCHECK(state_machine_.HasInitializedOutputSurface());
 
   advance_commit_state_task_.Cancel();
@@ -570,7 +567,7 @@ void Scheduler::ScheduleBeginImplFrameDeadline(base::TimeTicks deadline) {
   base::TimeDelta delta = deadline - gfx::FrameTime::Now();
   if (delta <= base::TimeDelta())
     delta = base::TimeDelta();
-  task_runner_->PostDelayedTask(
+  impl_task_runner_->PostDelayedTask(
       FROM_HERE, begin_impl_frame_deadline_task_.callback(), delta);
 }
 
diff --git a/cc/scheduler/scheduler.h b/cc/scheduler/scheduler.h
index ce3fed7..f6dd2bc 100644
--- a/cc/scheduler/scheduler.h
+++ b/cc/scheduler/scheduler.h
@@ -57,9 +57,9 @@ class CC_EXPORT Scheduler {
       SchedulerClient* client,
       const SchedulerSettings& scheduler_settings,
       int layer_tree_host_id,
-      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner) {
+      const scoped_refptr<base::SingleThreadTaskRunner>& impl_task_runner) {
     return make_scoped_ptr(new Scheduler(
-        client, scheduler_settings, layer_tree_host_id, task_runner));
+        client, scheduler_settings, layer_tree_host_id, impl_task_runner));
   }
 
   virtual ~Scheduler();
@@ -180,15 +180,16 @@ class CC_EXPORT Scheduler {
     scoped_refptr<DelayBasedTimeSource> time_source_;
   };
 
-  Scheduler(SchedulerClient* client,
-            const SchedulerSettings& scheduler_settings,
-            int layer_tree_host_id,
-            const scoped_refptr<base::SingleThreadTaskRunner>& task_runner);
+  Scheduler(
+      SchedulerClient* client,
+      const SchedulerSettings& scheduler_settings,
+      int layer_tree_host_id,
+      const scoped_refptr<base::SingleThreadTaskRunner>& impl_task_runner);
 
   const SchedulerSettings settings_;
   SchedulerClient* client_;
   int layer_tree_host_id_;
-  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner_;
 
   base::TimeDelta vsync_interval_;
   base::TimeDelta estimated_parent_draw_time_;
diff --git a/cc/test/fake_layer_tree_host_client.h b/cc/test/fake_layer_tree_host_client.h
index 7f7bd35..f928453 100644
--- a/cc/test/fake_layer_tree_host_client.h
+++ b/cc/test/fake_layer_tree_host_client.h
@@ -42,6 +42,8 @@ class FakeLayerTreeHostClient : public LayerTreeHostClient,
   virtual void DidCompleteSwapBuffers() OVERRIDE {}
 
   // LayerTreeHostSingleThreadClient implementation.
+  virtual void ScheduleComposite() OVERRIDE {}
+  virtual void ScheduleAnimation() OVERRIDE {}
   virtual void DidPostSwapBuffers() OVERRIDE {}
   virtual void DidAbortSwapBuffers() OVERRIDE {}
 
diff --git a/cc/test/layer_tree_test.cc b/cc/test/layer_tree_test.cc
index b9d5063..0be1ed1 100644
--- a/cc/test/layer_tree_test.cc
+++ b/cc/test/layer_tree_test.cc
@@ -312,6 +312,14 @@ class LayerTreeHostClientForTesting : public LayerTreeHostClient,
     test_hooks_->DidCompleteSwapBuffers();
   }
 
+  virtual void ScheduleComposite() OVERRIDE {
+    test_hooks_->ScheduleComposite();
+  }
+
+  virtual void ScheduleAnimation() OVERRIDE {
+    test_hooks_->ScheduleAnimation();
+  }
+
   virtual void DidPostSwapBuffers() OVERRIDE {}
   virtual void DidAbortSwapBuffers() OVERRIDE {}
 
@@ -386,6 +394,7 @@ LayerTreeTest::LayerTreeTest()
       end_when_begin_returns_(false),
       timed_out_(false),
       scheduled_(false),
+      schedule_when_set_visible_true_(false),
       started_(false),
       ended_(false),
       delegating_renderer_(false),
@@ -549,6 +558,15 @@ void LayerTreeTest::Timeout() {
   EndTest();
 }
 
+void LayerTreeTest::ScheduleComposite() {
+  if (!started_ || scheduled_)
+    return;
+  scheduled_ = true;
+  main_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&LayerTreeTest::DispatchComposite, main_thread_weak_ptr_));
+}
+
 void LayerTreeTest::RealEndTest() {
   if (layer_tree_host_ && !timed_out_ &&
       proxy()->MainFrameWillHappenForTesting()) {
@@ -601,8 +619,16 @@ void LayerTreeTest::DispatchSetNeedsRedrawRect(const gfx::Rect& damage_rect) {
 
 void LayerTreeTest::DispatchSetVisible(bool visible) {
   DCHECK(!proxy() || proxy()->IsMainThread());
-  if (layer_tree_host_)
-    layer_tree_host_->SetVisible(visible);
+
+  if (!layer_tree_host_)
+    return;
+
+  layer_tree_host_->SetVisible(visible);
+
+  // If the LTH is being made visible and a previous ScheduleComposite() was
+  // deferred because the LTH was not visible, re-schedule the composite now.
+  if (layer_tree_host_->visible() && schedule_when_set_visible_true_)
+    ScheduleComposite();
 }
 
 void LayerTreeTest::DispatchSetNextCommitForcesRedraw() {
@@ -612,6 +638,24 @@ void LayerTreeTest::DispatchSetNextCommitForcesRedraw() {
     layer_tree_host_->SetNextCommitForcesRedraw();
 }
 
+void LayerTreeTest::DispatchComposite() {
+  scheduled_ = false;
+
+  if (!layer_tree_host_)
+    return;
+
+  // If the LTH is not visible, defer the composite until the LTH is made
+  // visible.
+  if (!layer_tree_host_->visible()) {
+    schedule_when_set_visible_true_ = true;
+    return;
+  }
+
+  schedule_when_set_visible_true_ = false;
+  base::TimeTicks now = gfx::FrameTime::Now();
+  layer_tree_host_->Composite(now);
+}
+
 void LayerTreeTest::RunTest(bool threaded,
                             bool delegating_renderer,
                             bool impl_side_painting) {
diff --git a/cc/test/layer_tree_test.h b/cc/test/layer_tree_test.h
index 619ae96..8f38dda 100644
--- a/cc/test/layer_tree_test.h
+++ b/cc/test/layer_tree_test.h
@@ -71,6 +71,8 @@ class TestHooks : public AnimationDelegate {
   virtual void DidCommit() {}
   virtual void DidCommitAndDrawFrame() {}
   virtual void DidCompleteSwapBuffers() {}
+  virtual void ScheduleComposite() {}
+  virtual void ScheduleAnimation() {}
   virtual void DidDeferCommit() {}
   virtual void DidSetVisibleOnImplTree(LayerTreeHostImpl* host_impl,
                                        bool visible) {}
@@ -137,6 +139,8 @@ class LayerTreeTest : public testing::Test, public TestHooks {
 
   virtual void InitializeSettings(LayerTreeSettings* settings) {}
 
+  virtual void ScheduleComposite() OVERRIDE;
+
   void RealEndTest();
 
   virtual void DispatchAddAnimation(Layer* layer_to_receive_animation,
@@ -147,6 +151,7 @@ class LayerTreeTest : public testing::Test, public TestHooks {
   void DispatchSetNeedsRedrawRect(const gfx::Rect& damage_rect);
   void DispatchSetVisible(bool visible);
   void DispatchSetNextCommitForcesRedraw();
+  void DispatchComposite();
   void DispatchDidAddAnimation();
 
   virtual void AfterTest() = 0;
@@ -199,6 +204,7 @@ class LayerTreeTest : public testing::Test, public TestHooks {
   bool end_when_begin_returns_;
   bool timed_out_;
   bool scheduled_;
+  bool schedule_when_set_visible_true_;
   bool started_;
   bool ended_;
   bool delegating_renderer_;
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index c43072f..6d9e236 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -697,12 +697,8 @@ void LayerTreeHost::NotifyInputThrottledUntilCommit() {
 
 void LayerTreeHost::Composite(base::TimeTicks frame_begin_time) {
   DCHECK(!proxy_->HasImplThread());
-  // This function is only valid when not using the scheduler.
-  DCHECK(!settings_.single_thread_proxy_scheduler);
   SingleThreadProxy* proxy = static_cast<SingleThreadProxy*>(proxy_.get());
 
-  SetLayerTreeHostClientReady();
-
   if (output_surface_lost_)
     proxy->CreateAndInitializeOutputSurface();
   if (output_surface_lost_)
diff --git a/cc/trees/layer_tree_host_perftest.cc b/cc/trees/layer_tree_host_perftest.cc
index 4ddb1f2..70b2a64 100644
--- a/cc/trees/layer_tree_host_perftest.cc
+++ b/cc/trees/layer_tree_host_perftest.cc
@@ -228,8 +228,6 @@ class ScrollingLayerTreePerfTest : public LayerTreeHostPerfTestJsonReader {
   }
 
   virtual void Layout() OVERRIDE {
-    if (TestEnded())
-      return;
     static const gfx::Vector2d delta = gfx::Vector2d(0, 10);
     scrollable_->SetScrollOffset(scrollable_->scroll_offset() + delta);
   }
diff --git a/cc/trees/layer_tree_host_single_thread_client.h b/cc/trees/layer_tree_host_single_thread_client.h
index dbca28c..cb61450 100644
--- a/cc/trees/layer_tree_host_single_thread_client.h
+++ b/cc/trees/layer_tree_host_single_thread_client.h
@@ -10,10 +10,10 @@ namespace cc {
 class LayerTreeHostSingleThreadClient {
  public:
   // Request that the client schedule a composite.
-  virtual void ScheduleComposite() {}
+  virtual void ScheduleComposite() = 0;
   // Request that the client schedule a composite now, and calculate appropriate
   // delay for potential future frame.
-  virtual void ScheduleAnimation() {}
+  virtual void ScheduleAnimation() = 0;
 
   // Called whenever the compositor posts a SwapBuffers (either full or
   // partial). After DidPostSwapBuffers(), exactly one of
diff --git a/cc/trees/layer_tree_host_unittest.cc b/cc/trees/layer_tree_host_unittest.cc
index 9492884..0e72824 100644
--- a/cc/trees/layer_tree_host_unittest.cc
+++ b/cc/trees/layer_tree_host_unittest.cc
@@ -91,8 +91,8 @@ class LayerTreeHostTestSetNeedsCommit1 : public LayerTreeHostTest {
   }
 
   virtual void AfterTest() OVERRIDE {
-    EXPECT_LE(1, num_commits_);
-    EXPECT_LE(1, num_draws_);
+    EXPECT_GE(1, num_commits_);
+    EXPECT_GE(1, num_draws_);
   }
 
  private:
@@ -694,6 +694,31 @@ class LayerTreeHostTestUndrawnLayersPushContentBoundsLater
 SINGLE_AND_MULTI_THREAD_TEST_F(
     LayerTreeHostTestUndrawnLayersPushContentBoundsLater);
 
+class LayerTreeHostTestAbortFrameWhenInvisible : public LayerTreeHostTest {
+ public:
+  LayerTreeHostTestAbortFrameWhenInvisible() {}
+
+  virtual void BeginTest() OVERRIDE {
+    // Request a commit (from the main thread), Which will trigger the commit
+    // flow from the impl side.
+    layer_tree_host()->SetNeedsCommit();
+    // Then mark ourselves as not visible before processing any more messages
+    // on the main thread.
+    layer_tree_host()->SetVisible(false);
+    // If we make it without kicking a frame, we pass!
+    EndTestAfterDelay(1);
+  }
+
+  virtual void Layout() OVERRIDE {
+    ASSERT_FALSE(true);
+    EndTest();
+  }
+
+  virtual void AfterTest() OVERRIDE {}
+};
+
+MULTI_THREAD_TEST_F(LayerTreeHostTestAbortFrameWhenInvisible);
+
 // This test verifies that properties on the layer tree host are commited
 // to the impl side.
 class LayerTreeHostTestCommit : public LayerTreeHostTest {
@@ -1893,7 +1918,7 @@ class LayerTreeHostTestDeferCommits : public LayerTreeHostTest {
   int num_complete_commits_;
 };
 
-SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostTestDeferCommits);
+MULTI_THREAD_TEST_F(LayerTreeHostTestDeferCommits);
 
 class LayerTreeHostWithProxy : public LayerTreeHost {
  public:
@@ -1966,7 +1991,6 @@ TEST(LayerTreeHostTest, PartialUpdatesWithGLRenderer) {
 
   LayerTreeSettings settings;
   settings.max_partial_texture_updates = 4;
-  settings.single_thread_proxy_scheduler = false;
 
   scoped_ptr<SharedBitmapManager> shared_bitmap_manager(
       new TestSharedBitmapManager());
@@ -1986,7 +2010,6 @@ TEST(LayerTreeHostTest, PartialUpdatesWithSoftwareRenderer) {
 
   LayerTreeSettings settings;
   settings.max_partial_texture_updates = 4;
-  settings.single_thread_proxy_scheduler = false;
 
   scoped_ptr<SharedBitmapManager> shared_bitmap_manager(
       new TestSharedBitmapManager());
@@ -2006,7 +2029,6 @@ TEST(LayerTreeHostTest, PartialUpdatesWithDelegatingRendererAndGLContent) {
 
   LayerTreeSettings settings;
   settings.max_partial_texture_updates = 4;
-  settings.single_thread_proxy_scheduler = false;
 
   scoped_ptr<SharedBitmapManager> shared_bitmap_manager(
       new TestSharedBitmapManager());
@@ -2027,7 +2049,6 @@ TEST(LayerTreeHostTest,
 
   LayerTreeSettings settings;
   settings.max_partial_texture_updates = 4;
-  settings.single_thread_proxy_scheduler = false;
 
   scoped_ptr<SharedBitmapManager> shared_bitmap_manager(
       new TestSharedBitmapManager());
@@ -4526,7 +4547,7 @@ class LayerTreeHostTestBreakSwapPromise : public LayerTreeHostTest {
 // TODO(miletus): Flaky test: crbug.com/393995
 // MULTI_THREAD_TEST_F(LayerTreeHostTestBreakSwapPromise);
 
-class LayerTreeHostTestBreakSwapPromiseForVisibilityAbortedCommit
+class LayerTreeHostTestBreakSwapPromiseForAbortedCommit
     : public LayerTreeHostTest {
  protected:
   virtual void BeginTest() OVERRIDE { PostSetNeedsCommitToMainThread(); }
@@ -4562,59 +4583,7 @@ class LayerTreeHostTestBreakSwapPromiseForVisibilityAbortedCommit
   TestSwapPromiseResult swap_promise_result_;
 };
 
-SINGLE_AND_MULTI_THREAD_TEST_F(
-    LayerTreeHostTestBreakSwapPromiseForVisibilityAbortedCommit);
-
-class LayerTreeHostTestBreakSwapPromiseForContextAbortedCommit
-    : public LayerTreeHostTest {
- protected:
-  virtual void BeginTest() OVERRIDE { PostSetNeedsCommitToMainThread(); }
-
-  virtual void DidCommit() OVERRIDE {
-    if (TestEnded())
-      return;
-    layer_tree_host()->SetDeferCommits(true);
-    layer_tree_host()->SetNeedsCommit();
-  }
-
-  virtual void DidDeferCommit() OVERRIDE {
-    layer_tree_host()->DidLoseOutputSurface();
-    scoped_ptr<SwapPromise> swap_promise(
-        new TestSwapPromise(&swap_promise_result_));
-    layer_tree_host()->QueueSwapPromise(swap_promise.Pass());
-    layer_tree_host()->SetDeferCommits(false);
-  }
-
-  virtual void BeginMainFrameAbortedOnThread(LayerTreeHostImpl* host_impl,
-                                             bool did_handle) OVERRIDE {
-    EndTest();
-    // This lets the test finally commit and exit.
-    MainThreadTaskRunner()->PostTask(
-        FROM_HERE,
-        base::Bind(&LayerTreeHostTestBreakSwapPromiseForContextAbortedCommit::
-                       FindOutputSurface,
-                   base::Unretained(this)));
-  }
-
-  void FindOutputSurface() {
-    layer_tree_host()->OnCreateAndInitializeOutputSurfaceAttempted(true);
-  }
-
-  virtual void AfterTest() OVERRIDE {
-    {
-      base::AutoLock lock(swap_promise_result_.lock);
-      EXPECT_FALSE(swap_promise_result_.did_swap_called);
-      EXPECT_TRUE(swap_promise_result_.did_not_swap_called);
-      EXPECT_EQ(SwapPromise::COMMIT_FAILS, swap_promise_result_.reason);
-      EXPECT_TRUE(swap_promise_result_.dtor_called);
-    }
-  }
-
-  TestSwapPromiseResult swap_promise_result_;
-};
-
-SINGLE_AND_MULTI_THREAD_TEST_F(
-    LayerTreeHostTestBreakSwapPromiseForContextAbortedCommit);
+MULTI_THREAD_TEST_F(LayerTreeHostTestBreakSwapPromiseForAbortedCommit);
 
 class SimpleSwapPromiseMonitor : public SwapPromiseMonitor {
  public:
@@ -4699,7 +4668,7 @@ class LayerTreeHostTestSimpleSwapPromiseMonitor : public LayerTreeHostTest {
   virtual void AfterTest() OVERRIDE {}
 };
 
-SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostTestSimpleSwapPromiseMonitor);
+MULTI_THREAD_TEST_F(LayerTreeHostTestSimpleSwapPromiseMonitor);
 
 class LayerTreeHostTestHighResRequiredAfterEvictingUIResources
     : public LayerTreeHostTest {
diff --git a/cc/trees/layer_tree_host_unittest_context.cc b/cc/trees/layer_tree_host_unittest_context.cc
index 887e603..8fd9743 100644
--- a/cc/trees/layer_tree_host_unittest_context.cc
+++ b/cc/trees/layer_tree_host_unittest_context.cc
@@ -65,9 +65,6 @@ class LayerTreeHostContextTest : public LayerTreeTest {
   }
 
   void LoseContext() {
-    // For sanity-checking tests, they should only call this when the
-    // context is not lost.
-    CHECK(context3d_);
     context3d_->loseContextCHROMIUM(GL_GUILTY_CONTEXT_RESET_ARB,
                                     GL_INNOCENT_CONTEXT_RESET_ARB);
     context3d_ = NULL;
@@ -311,8 +308,7 @@ class LayerTreeHostClientNotReadyDoesNotCreateOutputSurface
   }
 };
 
-SINGLE_AND_MULTI_THREAD_TEST_F(
-    LayerTreeHostClientNotReadyDoesNotCreateOutputSurface);
+MULTI_THREAD_TEST_F(LayerTreeHostClientNotReadyDoesNotCreateOutputSurface);
 
 class LayerTreeHostContextTestLostContextSucceedsWithContent
     : public LayerTreeHostContextTestLostContextSucceeds {
@@ -370,11 +366,10 @@ class LayerTreeHostContextTestCreateOutputSurfaceFails
       : times_to_fail_(times_to_fail),
         expect_fallback_attempt_(expect_fallback_attempt),
         did_attempt_fallback_(false),
-        times_initialized_(0) {
-    times_to_fail_create_ = times_to_fail_;
-  }
+        times_initialized_(0) {}
 
   virtual void BeginTest() OVERRIDE {
+    times_to_fail_create_ = times_to_fail_;
     PostSetNeedsCommitToMainThread();
   }
 
@@ -988,6 +983,12 @@ class ScrollbarLayerLostContext : public LayerTreeHostContextTest {
         EXPECT_EQ(2, scrollbar_layer_->update_count());
         EndTest();
         break;
+      case 3:
+        // Single thread proxy issues extra commits after context lost.
+        // http://crbug.com/287250
+        if (HasImplThread())
+          NOTREACHED();
+        break;
       default:
         NOTREACHED();
     }
@@ -1031,10 +1032,12 @@ class UIResourceLostTest : public LayerTreeHostContextTest {
 
   void PostLoseContextToImplThread() {
     EXPECT_TRUE(layer_tree_host()->proxy()->IsMainThread());
-    ImplThreadTaskRunner()->PostTask(
-        FROM_HERE,
-        base::Bind(&LayerTreeHostContextTest::LoseContext,
-                   base::Unretained(this)));
+    base::SingleThreadTaskRunner* task_runner =
+        HasImplThread() ? ImplThreadTaskRunner()
+                        : base::MessageLoopProxy::current();
+    task_runner->PostTask(FROM_HERE,
+                          base::Bind(&LayerTreeHostContextTest::LoseContext,
+                                     base::Unretained(this)));
   }
 
  protected:
@@ -1089,8 +1092,13 @@ class UIResourceLostAfterCommit : public UIResourceLostTestSimple {
         EndTest();
         break;
       case 5:
-        NOTREACHED();
+        // Single thread proxy issues extra commits after context lost.
+        // http://crbug.com/287250
+        if (HasImplThread())
+          NOTREACHED();
         break;
+      case 6:
+        NOTREACHED();
     }
   }
 
@@ -1178,8 +1186,13 @@ class UIResourceLostBeforeCommit : public UIResourceLostTestSimple {
         EndTest();
         break;
       case 6:
-        NOTREACHED();
+        // Single thread proxy issues extra commits after context lost.
+        // http://crbug.com/287250
+        if (HasImplThread())
+          NOTREACHED();
         break;
+      case 8:
+        NOTREACHED();
     }
   }
 
@@ -1200,8 +1213,15 @@ class UIResourceLostBeforeCommit : public UIResourceLostTestSimple {
         // Sequence 2 (continued):
         // The previous resource should have been deleted.
         EXPECT_EQ(0u, impl->ResourceIdForUIResource(test_id0_));
-        // The second resource should have been created.
-        EXPECT_NE(0u, impl->ResourceIdForUIResource(test_id1_));
+        if (HasImplThread()) {
+          // The second resource should have been created.
+          EXPECT_NE(0u, impl->ResourceIdForUIResource(test_id1_));
+        } else {
+          // The extra commit that happens at context lost in the single thread
+          // proxy changes the timing so that the resource has been destroyed.
+          // http://crbug.com/287250
+          EXPECT_EQ(0u, impl->ResourceIdForUIResource(test_id1_));
+        }
         // The second resource called the resource callback once and since the
         // context is lost, a "resource lost" callback was also issued.
         EXPECT_EQ(2, ui_resource_->resource_create_count);
@@ -1517,8 +1537,8 @@ class LayerTreeHostContextTestLoseAfterSendingBeginMainFrame
   bool deferred_;
 };
 
-SINGLE_AND_MULTI_THREAD_TEST_F(
-    LayerTreeHostContextTestLoseAfterSendingBeginMainFrame);
+// TODO(danakj): We don't use scheduler with SingleThreadProxy yet.
+MULTI_THREAD_TEST_F(LayerTreeHostContextTestLoseAfterSendingBeginMainFrame);
 
 }  // namespace
 }  // namespace cc
diff --git a/cc/trees/layer_tree_host_unittest_no_message_loop.cc b/cc/trees/layer_tree_host_unittest_no_message_loop.cc
index ea3bfc6..1a24ba5 100644
--- a/cc/trees/layer_tree_host_unittest_no_message_loop.cc
+++ b/cc/trees/layer_tree_host_unittest_no_message_loop.cc
@@ -74,6 +74,8 @@ class LayerTreeHostNoMessageLoopTest
   virtual void DidCompleteSwapBuffers() OVERRIDE {}
 
   // LayerTreeHostSingleThreadClient overrides.
+  virtual void ScheduleComposite() OVERRIDE {}
+  virtual void ScheduleAnimation() OVERRIDE {}
   virtual void DidPostSwapBuffers() OVERRIDE {}
   virtual void DidAbortSwapBuffers() OVERRIDE {}
 
@@ -94,7 +96,6 @@ class LayerTreeHostNoMessageLoopTest
 
   void SetupLayerTreeHost() {
     LayerTreeSettings settings;
-    settings.single_thread_proxy_scheduler = false;
     layer_tree_host_ =
         LayerTreeHost::CreateSingleThreaded(this, this, NULL, settings, NULL);
     layer_tree_host_->SetViewportSize(size_);
diff --git a/cc/trees/layer_tree_settings.cc b/cc/trees/layer_tree_settings.cc
index 56e18a2..bf72893 100644
--- a/cc/trees/layer_tree_settings.cc
+++ b/cc/trees/layer_tree_settings.cc
@@ -16,7 +16,6 @@ LayerTreeSettings::LayerTreeSettings()
     : impl_side_painting(false),
       allow_antialiasing(true),
       throttle_frame_production(true),
-      single_thread_proxy_scheduler(true),
       begin_frame_scheduling_enabled(false),
       main_frame_before_draw_enabled(true),
       main_frame_before_activation_enabled(false),
diff --git a/cc/trees/layer_tree_settings.h b/cc/trees/layer_tree_settings.h
index bad3bf4..14cec67 100644
--- a/cc/trees/layer_tree_settings.h
+++ b/cc/trees/layer_tree_settings.h
@@ -21,7 +21,6 @@ class CC_EXPORT LayerTreeSettings {
   bool impl_side_painting;
   bool allow_antialiasing;
   bool throttle_frame_production;
-  bool single_thread_proxy_scheduler;
   bool begin_frame_scheduling_enabled;
   bool main_frame_before_draw_enabled;
   bool main_frame_before_activation_enabled;
diff --git a/cc/trees/scoped_abort_remaining_swap_promises.h b/cc/trees/scoped_abort_remaining_swap_promises.h
deleted file mode 100644
index f8dfc01..0000000
--- a/cc/trees/scoped_abort_remaining_swap_promises.h
+++ /dev/null
@@ -1,30 +0,0 @@
-// Copyright 2014 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.
-
-#ifndef CC_TREES_SCOPED_ABORT_REMAINING_SWAP_PROMISES_H_
-#define CC_TREES_SCOPED_ABORT_REMAINING_SWAP_PROMISES_H_
-
-#include "cc/base/swap_promise.h"
-#include "cc/trees/layer_tree_host.h"
-
-namespace cc {
-
-class ScopedAbortRemainingSwapPromises {
- public:
-  explicit ScopedAbortRemainingSwapPromises(LayerTreeHost* layer_tree_host)
-      : layer_tree_host_(layer_tree_host) {}
-
-  ~ScopedAbortRemainingSwapPromises() {
-    layer_tree_host_->BreakSwapPromises(SwapPromise::COMMIT_FAILS);
-  }
-
- private:
-  LayerTreeHost* layer_tree_host_;
-
-  DISALLOW_COPY_AND_ASSIGN(ScopedAbortRemainingSwapPromises);
-};
-
-}  // namespace cc
-
-#endif  // CC_TREES_SCOPED_ABORT_REMAINING_SWAP_PROMISES_H_
diff --git a/cc/trees/single_thread_proxy.cc b/cc/trees/single_thread_proxy.cc
index 7be4ca8..f400733 100644
--- a/cc/trees/single_thread_proxy.cc
+++ b/cc/trees/single_thread_proxy.cc
@@ -16,7 +16,6 @@
 #include "cc/trees/layer_tree_host.h"
 #include "cc/trees/layer_tree_host_single_thread_client.h"
 #include "cc/trees/layer_tree_impl.h"
-#include "cc/trees/scoped_abort_remaining_swap_promises.h"
 #include "ui/gfx/frame_time.h"
 
 namespace cc {
@@ -37,13 +36,8 @@ SingleThreadProxy::SingleThreadProxy(
     : Proxy(main_task_runner, NULL),
       layer_tree_host_(layer_tree_host),
       client_(client),
-      timing_history_(layer_tree_host->rendering_stats_instrumentation()),
       next_frame_is_newly_committed_frame_(false),
-      inside_draw_(false),
-      defer_commits_(false),
-      commit_was_deferred_(false),
-      commit_requested_(false),
-      weak_factory_(this) {
+      inside_draw_(false) {
   TRACE_EVENT0("cc", "SingleThreadProxy::SingleThreadProxy");
   DCHECK(Proxy::IsMainThread());
   DCHECK(layer_tree_host);
@@ -83,26 +77,13 @@ void SingleThreadProxy::SetLayerTreeHostClientReady() {
   TRACE_EVENT0("cc", "SingleThreadProxy::SetLayerTreeHostClientReady");
   // Scheduling is controlled by the embedder in the single thread case, so
   // nothing to do.
-  DCHECK(Proxy::IsMainThread());
-  DebugScopedSetImplThread impl(this);
-  if (layer_tree_host_->settings().single_thread_proxy_scheduler &&
-      !scheduler_on_impl_thread_) {
-    SchedulerSettings scheduler_settings(layer_tree_host_->settings());
-    scheduler_on_impl_thread_ = Scheduler::Create(this,
-                                                  scheduler_settings,
-                                                  layer_tree_host_->id(),
-                                                  MainThreadTaskRunner());
-    scheduler_on_impl_thread_->SetCanStart();
-    scheduler_on_impl_thread_->SetVisible(layer_tree_host_impl_->visible());
-  }
 }
 
 void SingleThreadProxy::SetVisible(bool visible) {
   TRACE_EVENT0("cc", "SingleThreadProxy::SetVisible");
   DebugScopedSetImplThread impl(this);
   layer_tree_host_impl_->SetVisible(visible);
-  if (scheduler_on_impl_thread_)
-    scheduler_on_impl_thread_->SetVisible(layer_tree_host_impl_->visible());
+
   // Changing visibility could change ShouldComposite().
   UpdateBackgroundAnimateTicking();
 }
@@ -129,14 +110,9 @@ void SingleThreadProxy::CreateAndInitializeOutputSurface() {
 
   layer_tree_host_->OnCreateAndInitializeOutputSurfaceAttempted(success);
 
-  if (success) {
-    if (scheduler_on_impl_thread_)
-      scheduler_on_impl_thread_->DidCreateAndInitializeOutputSurface();
-  } else if (Proxy::MainThreadTaskRunner()) {
-    MainThreadTaskRunner()->PostTask(
-        FROM_HERE,
-        base::Bind(&SingleThreadProxy::CreateAndInitializeOutputSurface,
-                   weak_factory_.GetWeakPtr()));
+  if (!success) {
+    // Force another recreation attempt to happen by requesting another commit.
+    SetNeedsCommit();
   }
 }
 
@@ -150,40 +126,17 @@ void SingleThreadProxy::SetNeedsAnimate() {
   TRACE_EVENT0("cc", "SingleThreadProxy::SetNeedsAnimate");
   DCHECK(Proxy::IsMainThread());
   client_->ScheduleAnimation();
-  SetNeedsCommit();
 }
 
 void SingleThreadProxy::SetNeedsUpdateLayers() {
   TRACE_EVENT0("cc", "SingleThreadProxy::SetNeedsUpdateLayers");
   DCHECK(Proxy::IsMainThread());
-  SetNeedsCommit();
+  client_->ScheduleComposite();
 }
 
-void SingleThreadProxy::DoCommit(base::TimeTicks frame_begin_time) {
+void SingleThreadProxy::DoCommit(scoped_ptr<ResourceUpdateQueue> queue) {
   TRACE_EVENT0("cc", "SingleThreadProxy::DoCommit");
   DCHECK(Proxy::IsMainThread());
-  layer_tree_host_->WillBeginMainFrame();
-  layer_tree_host_->UpdateClientAnimations(frame_begin_time);
-  layer_tree_host_->AnimateLayers(frame_begin_time);
-  layer_tree_host_->Layout();
-  commit_requested_ = false;
-
-  if (PrioritizedResourceManager* contents_texture_manager =
-          layer_tree_host_->contents_texture_manager()) {
-    contents_texture_manager->UnlinkAndClearEvictedBackings();
-    contents_texture_manager->SetMaxMemoryLimitBytes(
-        layer_tree_host_impl_->memory_allocation_limit_bytes());
-    contents_texture_manager->SetExternalPriorityCutoff(
-        layer_tree_host_impl_->memory_allocation_priority_cutoff());
-  }
-
-  scoped_ptr<ResourceUpdateQueue> queue =
-      make_scoped_ptr(new ResourceUpdateQueue);
-
-  layer_tree_host_->UpdateLayers(queue.get());
-
-  layer_tree_host_->WillCommit();
-
   // Commit immediately.
   {
     DebugScopedSetMainThreadBlocked main_thread_blocked(this);
@@ -205,7 +158,7 @@ void SingleThreadProxy::DoCommit(base::TimeTicks frame_begin_time) {
     scoped_ptr<ResourceUpdateController> update_controller =
         ResourceUpdateController::Create(
             NULL,
-            MainThreadTaskRunner(),
+            Proxy::MainThreadTaskRunner(),
             queue.Pass(),
             layer_tree_host_impl_->resource_provider());
     update_controller->Finalize();
@@ -217,8 +170,6 @@ void SingleThreadProxy::DoCommit(base::TimeTicks frame_begin_time) {
 
     layer_tree_host_impl_->CommitComplete();
 
-    UpdateBackgroundAnimateTicking();
-
 #if DCHECK_IS_ON
     // In the single-threaded case, the scale and scroll deltas should never be
     // touched on the impl layer tree.
@@ -235,62 +186,33 @@ void SingleThreadProxy::DoCommit(base::TimeTicks frame_begin_time) {
     stats_instrumentation->AccumulateAndClearMainThreadStats();
   }
   layer_tree_host_->CommitComplete();
-  layer_tree_host_->DidBeginMainFrame();
-  timing_history_.DidCommit();
-
   next_frame_is_newly_committed_frame_ = true;
 }
 
 void SingleThreadProxy::SetNeedsCommit() {
   DCHECK(Proxy::IsMainThread());
-  DebugScopedSetImplThread impl(this);
   client_->ScheduleComposite();
-  if (scheduler_on_impl_thread_)
-    scheduler_on_impl_thread_->SetNeedsCommit();
-  commit_requested_ = true;
 }
 
 void SingleThreadProxy::SetNeedsRedraw(const gfx::Rect& damage_rect) {
   TRACE_EVENT0("cc", "SingleThreadProxy::SetNeedsRedraw");
-  DCHECK(Proxy::IsMainThread());
-  DebugScopedSetImplThread impl(this);
-  client_->ScheduleComposite();
   SetNeedsRedrawRectOnImplThread(damage_rect);
+  client_->ScheduleComposite();
 }
 
 void SingleThreadProxy::SetNextCommitWaitsForActivation() {
   // There is no activation here other than commit. So do nothing.
-  DCHECK(Proxy::IsMainThread());
 }
 
 void SingleThreadProxy::SetDeferCommits(bool defer_commits) {
-  DCHECK(Proxy::IsMainThread());
-  // Deferring commits only makes sense if there's a scheduler.
-  if (!scheduler_on_impl_thread_)
-    return;
-  if (defer_commits_ == defer_commits)
-    return;
-
-  if (defer_commits)
-    TRACE_EVENT_ASYNC_BEGIN0("cc", "SingleThreadProxy::SetDeferCommits", this);
-  else
-    TRACE_EVENT_ASYNC_END0("cc", "SingleThreadProxy::SetDeferCommits", this);
-
-  defer_commits_ = defer_commits;
-  if (!defer_commits_ && commit_was_deferred_) {
-    commit_was_deferred_ = false;
-    BeginMainFrame();
-  }
 }
 
 bool SingleThreadProxy::CommitRequested() const {
-  DCHECK(Proxy::IsMainThread());
-  return commit_requested_;
+  return false;
 }
 
 bool SingleThreadProxy::BeginMainFrameRequested() const {
-  DCHECK(Proxy::IsMainThread());
-  return commit_requested_;
+  return false;
 }
 
 size_t SingleThreadProxy::MaxPartialTextureUpdates() const {
@@ -307,7 +229,6 @@ void SingleThreadProxy::Stop() {
     BlockingTaskRunner::CapturePostTasks blocked;
     layer_tree_host_->DeleteContentsTexturesOnImplThread(
         layer_tree_host_impl_->resource_provider());
-    scheduler_on_impl_thread_.reset();
     layer_tree_host_impl_.reset();
   }
   layer_tree_host_ = NULL;
@@ -318,19 +239,15 @@ void SingleThreadProxy::OnCanDrawStateChanged(bool can_draw) {
       "cc", "SingleThreadProxy::OnCanDrawStateChanged", "can_draw", can_draw);
   DCHECK(Proxy::IsImplThread());
   UpdateBackgroundAnimateTicking();
-  if (scheduler_on_impl_thread_)
-    scheduler_on_impl_thread_->SetCanDraw(can_draw);
 }
 
 void SingleThreadProxy::NotifyReadyToActivate() {
-  // Impl-side painting only.
+  // Thread-only feature.
   NOTREACHED();
 }
 
 void SingleThreadProxy::SetNeedsRedrawOnImplThread() {
   client_->ScheduleComposite();
-  if (scheduler_on_impl_thread_)
-    scheduler_on_impl_thread_->SetNeedsRedraw();
 }
 
 void SingleThreadProxy::SetNeedsAnimateOnImplThread() {
@@ -338,14 +255,17 @@ void SingleThreadProxy::SetNeedsAnimateOnImplThread() {
 }
 
 void SingleThreadProxy::SetNeedsManageTilesOnImplThread() {
-  // Impl-side painting only.
+  // Thread-only/Impl-side-painting-only feature.
   NOTREACHED();
 }
 
 void SingleThreadProxy::SetNeedsRedrawRectOnImplThread(
     const gfx::Rect& damage_rect) {
+  // TODO(brianderson): Once we move render_widget scheduling into this class,
+  // we can treat redraw requests more efficiently than CommitAndRedraw
+  // requests.
   layer_tree_host_impl_->SetViewportDamage(damage_rect);
-  SetNeedsRedrawOnImplThread();
+  SetNeedsCommit();
 }
 
 void SingleThreadProxy::DidInitializeVisibleTileOnImplThread() {
@@ -355,8 +275,6 @@ void SingleThreadProxy::DidInitializeVisibleTileOnImplThread() {
 
 void SingleThreadProxy::SetNeedsCommitOnImplThread() {
   client_->ScheduleComposite();
-  if (scheduler_on_impl_thread_)
-    scheduler_on_impl_thread_->SetNeedsCommit();
 }
 
 void SingleThreadProxy::PostAnimationEventsToMainThreadOnImplThread(
@@ -393,53 +311,66 @@ void SingleThreadProxy::UpdateRendererCapabilitiesOnImplThread() {
       layer_tree_host_impl_->GetRendererCapabilities().MainThreadCapabilities();
 }
 
-void SingleThreadProxy::DidManageTiles() {
-  // Impl-side painting only.
-  NOTREACHED();
-}
-
 void SingleThreadProxy::DidLoseOutputSurfaceOnImplThread() {
   TRACE_EVENT0("cc", "SingleThreadProxy::DidLoseOutputSurfaceOnImplThread");
-  {
-    DebugScopedSetMainThread main(this);
-    // This must happen before we notify the scheduler as it may try to recreate
-    // the output surface if already in BEGIN_IMPL_FRAME_STATE_IDLE.
-    layer_tree_host_->DidLoseOutputSurface();
-  }
+  // Cause a commit so we can notice the lost context.
+  SetNeedsCommitOnImplThread();
   client_->DidAbortSwapBuffers();
-  if (scheduler_on_impl_thread_)
-    scheduler_on_impl_thread_->DidLoseOutputSurface();
 }
 
 void SingleThreadProxy::DidSwapBuffersOnImplThread() {
-  TRACE_EVENT0("cc", "SingleThreadProxy::DidSwapBuffersOnImplThread");
-  if (scheduler_on_impl_thread_)
-    scheduler_on_impl_thread_->DidSwapBuffers();
   client_->DidPostSwapBuffers();
 }
 
 void SingleThreadProxy::DidSwapBuffersCompleteOnImplThread() {
   TRACE_EVENT0("cc", "SingleThreadProxy::DidSwapBuffersCompleteOnImplThread");
-  if (scheduler_on_impl_thread_)
-    scheduler_on_impl_thread_->DidSwapBuffersComplete();
-  layer_tree_host_->DidCompleteSwapBuffers();
-}
-
-void SingleThreadProxy::BeginFrame(const BeginFrameArgs& args) {
-  TRACE_EVENT0("cc", "SingleThreadProxy::BeginFrame");
-  if (scheduler_on_impl_thread_)
-    scheduler_on_impl_thread_->BeginImplFrame(args);
+  client_->DidCompleteSwapBuffers();
 }
 
+// Called by the legacy scheduling path (e.g. where render_widget does the
+// scheduling)
 void SingleThreadProxy::CompositeImmediately(base::TimeTicks frame_begin_time) {
   TRACE_EVENT0("cc", "SingleThreadProxy::CompositeImmediately");
   DCHECK(Proxy::IsMainThread());
   DCHECK(!layer_tree_host_->output_surface_lost());
 
-  DoCommit(frame_begin_time);
+  layer_tree_host_->AnimateLayers(frame_begin_time);
+
+  if (PrioritizedResourceManager* contents_texture_manager =
+          layer_tree_host_->contents_texture_manager()) {
+    contents_texture_manager->UnlinkAndClearEvictedBackings();
+    contents_texture_manager->SetMaxMemoryLimitBytes(
+        layer_tree_host_impl_->memory_allocation_limit_bytes());
+    contents_texture_manager->SetExternalPriorityCutoff(
+        layer_tree_host_impl_->memory_allocation_priority_cutoff());
+  }
+
+  scoped_ptr<ResourceUpdateQueue> queue =
+      make_scoped_ptr(new ResourceUpdateQueue);
+  layer_tree_host_->UpdateLayers(queue.get());
+  layer_tree_host_->WillCommit();
+  DoCommit(queue.Pass());
+  layer_tree_host_->DidBeginMainFrame();
 
   LayerTreeHostImpl::FrameData frame;
-  DoComposite(frame_begin_time, &frame);
+  if (DoComposite(frame_begin_time, &frame)) {
+    {
+      DebugScopedSetMainThreadBlocked main_thread_blocked(this);
+      DebugScopedSetImplThread impl(this);
+
+      // This CapturePostTasks should be destroyed before
+      // DidCommitAndDrawFrame() is called since that goes out to the embedder,
+      // and we want the embedder to receive its callbacks before that.
+      // NOTE: This maintains consistent ordering with the ThreadProxy since
+      // the DidCommitAndDrawFrame() must be post-tasked from the impl thread
+      // there as the main thread is not blocked, so any posted tasks inside
+      // the swap buffers will execute first.
+      BlockingTaskRunner::CapturePostTasks blocked;
+
+      layer_tree_host_impl_->SwapBuffers(frame);
+    }
+    DidSwapFrame();
+  }
 }
 
 void SingleThreadProxy::AsValueInto(base::debug::TracedValue* state) const {
@@ -479,11 +410,12 @@ void SingleThreadProxy::UpdateBackgroundAnimateTicking() {
       !ShouldComposite() && layer_tree_host_impl_->active_tree()->root_layer());
 }
 
-DrawResult SingleThreadProxy::DoComposite(base::TimeTicks frame_begin_time,
-                                          LayerTreeHostImpl::FrameData* frame) {
+bool SingleThreadProxy::DoComposite(base::TimeTicks frame_begin_time,
+                                    LayerTreeHostImpl::FrameData* frame) {
   TRACE_EVENT0("cc", "SingleThreadProxy::DoComposite");
   DCHECK(!layer_tree_host_->output_surface_lost());
 
+  bool lost_output_surface = false;
   {
     DebugScopedSetImplThread impl(this);
     base::AutoReset<bool> mark_inside(&inside_draw_, true);
@@ -494,11 +426,9 @@ DrawResult SingleThreadProxy::DoComposite(base::TimeTicks frame_begin_time,
     // CanDraw() as well.
     if (!ShouldComposite()) {
       UpdateBackgroundAnimateTicking();
-      return DRAW_ABORTED_CANT_DRAW;
+      return false;
     }
 
-    timing_history_.DidStartDrawing();
-
     layer_tree_host_impl_->Animate(
         layer_tree_host_impl_->CurrentFrameTimeTicks());
     UpdateBackgroundAnimateTicking();
@@ -508,43 +438,24 @@ DrawResult SingleThreadProxy::DoComposite(base::TimeTicks frame_begin_time,
       layer_tree_host_impl_->DrawLayers(frame, frame_begin_time);
       layer_tree_host_impl_->DidDrawAllLayers(*frame);
     }
+    lost_output_surface = layer_tree_host_impl_->IsContextLost();
 
     bool start_ready_animations = true;
     layer_tree_host_impl_->UpdateAnimationState(start_ready_animations);
 
     layer_tree_host_impl_->ResetCurrentFrameTimeForNextFrame();
-
-    timing_history_.DidFinishDrawing();
   }
 
-  {
-    DebugScopedSetImplThread impl(this);
-
-    if (layer_tree_host_impl_->IsContextLost()) {
-      DidLoseOutputSurfaceOnImplThread();
-    } else {
-      // This CapturePostTasks should be destroyed before
-      // DidCommitAndDrawFrame() is called since that goes out to the
-      // embedder,
-      // and we want the embedder to receive its callbacks before that.
-      // NOTE: This maintains consistent ordering with the ThreadProxy since
-      // the DidCommitAndDrawFrame() must be post-tasked from the impl thread
-      // there as the main thread is not blocked, so any posted tasks inside
-      // the swap buffers will execute first.
-      DebugScopedSetMainThreadBlocked main_thread_blocked(this);
-
-      BlockingTaskRunner::CapturePostTasks blocked;
-      layer_tree_host_impl_->SwapBuffers(*frame);
-    }
+  if (lost_output_surface) {
+    layer_tree_host_->DidLoseOutputSurface();
+    return false;
   }
-  DidCommitAndDrawFrame();
 
-  return DRAW_SUCCESS;
+  return true;
 }
 
-void SingleThreadProxy::DidCommitAndDrawFrame() {
+void SingleThreadProxy::DidSwapFrame() {
   if (next_frame_is_newly_committed_frame_) {
-    DebugScopedSetMainThread main(this);
     next_frame_is_newly_committed_frame_ = false;
     layer_tree_host_->DidCommitAndDrawFrame();
   }
@@ -554,146 +465,4 @@ bool SingleThreadProxy::MainFrameWillHappenForTesting() {
   return false;
 }
 
-void SingleThreadProxy::SetNeedsBeginFrame(bool enable) {
-  layer_tree_host_impl_->SetNeedsBeginFrame(enable);
-}
-
-void SingleThreadProxy::WillBeginImplFrame(const BeginFrameArgs& args) {
-  layer_tree_host_impl_->WillBeginImplFrame(args);
-}
-
-void SingleThreadProxy::ScheduledActionSendBeginMainFrame() {
-  TRACE_EVENT0("cc", "SingleThreadProxy::ScheduledActionSendBeginMainFrame");
-  // Although this proxy is single-threaded, it's problematic to synchronously
-  // have BeginMainFrame happen after ScheduledActionSendBeginMainFrame.  This
-  // could cause a commit to occur in between a series of SetNeedsCommit calls
-  // (i.e. property modifications) causing some to fall on one frame and some to
-  // fall on the next.  Doing it asynchronously instead matches the semantics of
-  // ThreadProxy::SetNeedsCommit where SetNeedsCommit will not cause a
-  // synchronous commit.
-  MainThreadTaskRunner()->PostTask(
-      FROM_HERE,
-      base::Bind(&SingleThreadProxy::BeginMainFrame,
-                 weak_factory_.GetWeakPtr()));
-}
-
-void SingleThreadProxy::BeginMainFrame() {
-  if (defer_commits_) {
-    DCHECK(!commit_was_deferred_);
-    commit_was_deferred_ = true;
-    layer_tree_host_->DidDeferCommit();
-    return;
-  }
-
-  // This checker assumes NotifyReadyToCommit below causes a synchronous commit.
-  ScopedAbortRemainingSwapPromises swap_promise_checker(layer_tree_host_);
-
-  if (!layer_tree_host_->visible()) {
-    TRACE_EVENT_INSTANT0("cc", "EarlyOut_NotVisible", TRACE_EVENT_SCOPE_THREAD);
-    BeginMainFrameAbortedOnImplThread();
-    return;
-  }
-
-  if (layer_tree_host_->output_surface_lost()) {
-    TRACE_EVENT_INSTANT0(
-        "cc", "EarlyOut_OutputSurfaceLost", TRACE_EVENT_SCOPE_THREAD);
-    BeginMainFrameAbortedOnImplThread();
-    return;
-  }
-
-  timing_history_.DidBeginMainFrame();
-
-  DCHECK(scheduler_on_impl_thread_);
-  scheduler_on_impl_thread_->NotifyBeginMainFrameStarted();
-  scheduler_on_impl_thread_->NotifyReadyToCommit();
-}
-
-void SingleThreadProxy::BeginMainFrameAbortedOnImplThread() {
-  DebugScopedSetImplThread impl(this);
-  DCHECK(scheduler_on_impl_thread_->CommitPending());
-  DCHECK(!layer_tree_host_impl_->pending_tree());
-
-  // TODO(enne): SingleThreadProxy does not support cancelling commits yet so
-  // did_handle is always false.
-  bool did_handle = false;
-  layer_tree_host_impl_->BeginMainFrameAborted(did_handle);
-  scheduler_on_impl_thread_->BeginMainFrameAborted(did_handle);
-}
-
-DrawResult SingleThreadProxy::ScheduledActionDrawAndSwapIfPossible() {
-  DebugScopedSetImplThread impl(this);
-  if (layer_tree_host_impl_->IsContextLost()) {
-    DidCommitAndDrawFrame();
-    return DRAW_SUCCESS;
-  }
-
-  LayerTreeHostImpl::FrameData frame;
-  return DoComposite(layer_tree_host_impl_->CurrentFrameTimeTicks(), &frame);
-}
-
-DrawResult SingleThreadProxy::ScheduledActionDrawAndSwapForced() {
-  NOTREACHED();
-  return INVALID_RESULT;
-}
-
-void SingleThreadProxy::ScheduledActionCommit() {
-  DebugScopedSetMainThread main(this);
-  DoCommit(layer_tree_host_impl_->CurrentFrameTimeTicks());
-}
-
-void SingleThreadProxy::ScheduledActionAnimate() {
-  TRACE_EVENT0("cc", "ScheduledActionAnimate");
-  layer_tree_host_impl_->Animate(
-      layer_tree_host_impl_->CurrentFrameTimeTicks());
-}
-
-void SingleThreadProxy::ScheduledActionUpdateVisibleTiles() {
-  // Impl-side painting only.
-  NOTREACHED();
-}
-
-void SingleThreadProxy::ScheduledActionActivateSyncTree() {
-}
-
-void SingleThreadProxy::ScheduledActionBeginOutputSurfaceCreation() {
-  DebugScopedSetMainThread main(this);
-  DCHECK(scheduler_on_impl_thread_);
-  // If possible, create the output surface in a post task.  Synchronously
-  // creating the output surface makes tests more awkward since this differs
-  // from the ThreadProxy behavior.  However, sometimes there is no
-  // task runner.
-  if (Proxy::MainThreadTaskRunner()) {
-    MainThreadTaskRunner()->PostTask(
-        FROM_HERE,
-        base::Bind(&SingleThreadProxy::CreateAndInitializeOutputSurface,
-                   weak_factory_.GetWeakPtr()));
-  } else {
-    CreateAndInitializeOutputSurface();
-  }
-}
-
-void SingleThreadProxy::ScheduledActionManageTiles() {
-  // Impl-side painting only.
-  NOTREACHED();
-}
-
-void SingleThreadProxy::DidAnticipatedDrawTimeChange(base::TimeTicks time) {
-}
-
-base::TimeDelta SingleThreadProxy::DrawDurationEstimate() {
-  return timing_history_.DrawDurationEstimate();
-}
-
-base::TimeDelta SingleThreadProxy::BeginMainFrameToCommitDurationEstimate() {
-  return timing_history_.BeginMainFrameToCommitDurationEstimate();
-}
-
-base::TimeDelta SingleThreadProxy::CommitToActivateDurationEstimate() {
-  return timing_history_.CommitToActivateDurationEstimate();
-}
-
-void SingleThreadProxy::DidBeginImplFrameDeadline() {
-  layer_tree_host_impl_->ResetCurrentFrameTimeForNextFrame();
-}
-
 }  // namespace cc
diff --git a/cc/trees/single_thread_proxy.h b/cc/trees/single_thread_proxy.h
index d06c54b..685b11a 100644
--- a/cc/trees/single_thread_proxy.h
+++ b/cc/trees/single_thread_proxy.h
@@ -10,10 +10,8 @@
 #include "base/time/time.h"
 #include "cc/animation/animation_events.h"
 #include "cc/output/begin_frame_args.h"
-#include "cc/scheduler/scheduler.h"
 #include "cc/trees/layer_tree_host_impl.h"
 #include "cc/trees/proxy.h"
-#include "cc/trees/proxy_timing_history.h"
 
 namespace cc {
 
@@ -22,8 +20,7 @@ class LayerTreeHost;
 class LayerTreeHostSingleThreadClient;
 
 class CC_EXPORT SingleThreadProxy : public Proxy,
-                                    NON_EXPORTED_BASE(LayerTreeHostImplClient),
-                                    SchedulerClient {
+                                    NON_EXPORTED_BASE(LayerTreeHostImplClient) {
  public:
   static scoped_ptr<Proxy> Create(
       LayerTreeHost* layer_tree_host,
@@ -55,24 +52,6 @@ class CC_EXPORT SingleThreadProxy : public Proxy,
   virtual void AsValueInto(base::debug::TracedValue* state) const OVERRIDE;
   virtual bool MainFrameWillHappenForTesting() OVERRIDE;
 
-  // SchedulerClient implementation
-  virtual void SetNeedsBeginFrame(bool enable) OVERRIDE;
-  virtual void WillBeginImplFrame(const BeginFrameArgs& args) OVERRIDE;
-  virtual void ScheduledActionSendBeginMainFrame() OVERRIDE;
-  virtual DrawResult ScheduledActionDrawAndSwapIfPossible() OVERRIDE;
-  virtual DrawResult ScheduledActionDrawAndSwapForced() OVERRIDE;
-  virtual void ScheduledActionCommit() OVERRIDE;
-  virtual void ScheduledActionAnimate() OVERRIDE;
-  virtual void ScheduledActionUpdateVisibleTiles() OVERRIDE;
-  virtual void ScheduledActionActivateSyncTree() OVERRIDE;
-  virtual void ScheduledActionBeginOutputSurfaceCreation() OVERRIDE;
-  virtual void ScheduledActionManageTiles() OVERRIDE;
-  virtual void DidAnticipatedDrawTimeChange(base::TimeTicks time) OVERRIDE;
-  virtual base::TimeDelta DrawDurationEstimate() OVERRIDE;
-  virtual base::TimeDelta BeginMainFrameToCommitDurationEstimate() OVERRIDE;
-  virtual base::TimeDelta CommitToActivateDurationEstimate() OVERRIDE;
-  virtual void DidBeginImplFrameDeadline() OVERRIDE;
-
   // LayerTreeHostImplClient implementation
   virtual void UpdateRendererCapabilitiesOnImplThread() OVERRIDE;
   virtual void DidLoseOutputSurfaceOnImplThread() OVERRIDE;
@@ -82,7 +61,7 @@ class CC_EXPORT SingleThreadProxy : public Proxy,
   virtual void SetMaxSwapsPendingOnImplThread(int max) OVERRIDE {}
   virtual void DidSwapBuffersOnImplThread() OVERRIDE;
   virtual void DidSwapBuffersCompleteOnImplThread() OVERRIDE;
-  virtual void BeginFrame(const BeginFrameArgs& args) OVERRIDE;
+  virtual void BeginFrame(const BeginFrameArgs& args) OVERRIDE {}
   virtual void OnCanDrawStateChanged(bool can_draw) OVERRIDE;
   virtual void NotifyReadyToActivate() OVERRIDE;
   virtual void SetNeedsRedrawOnImplThread() OVERRIDE;
@@ -103,7 +82,7 @@ class CC_EXPORT SingleThreadProxy : public Proxy,
       const base::Closure& start_fade,
       base::TimeDelta delay) OVERRIDE {}
   virtual void DidActivateSyncTree() OVERRIDE {}
-  virtual void DidManageTiles() OVERRIDE;
+  virtual void DidManageTiles() OVERRIDE {}
   virtual void SetDebugState(const LayerTreeDebugState& debug_state) OVERRIDE {}
 
   // Attempts to create the context and renderer synchronously. Calls
@@ -119,13 +98,10 @@ class CC_EXPORT SingleThreadProxy : public Proxy,
       LayerTreeHostSingleThreadClient* client,
       scoped_refptr<base::SingleThreadTaskRunner> main_task_runner);
 
-  void BeginMainFrame();
-  void BeginMainFrameAbortedOnImplThread();
-  void DoCommit(base::TimeTicks frame_begin_time);
-  DrawResult DoComposite(base::TimeTicks frame_begin_time,
-                         LayerTreeHostImpl::FrameData* frame);
-  void DoSwap();
-  void DidCommitAndDrawFrame();
+  void DoCommit(scoped_ptr<ResourceUpdateQueue> queue);
+  bool DoComposite(base::TimeTicks frame_begin_time,
+                   LayerTreeHostImpl::FrameData* frame);
+  void DidSwapFrame();
 
   bool ShouldComposite() const;
   void UpdateBackgroundAnimateTicking();
@@ -139,18 +115,9 @@ class CC_EXPORT SingleThreadProxy : public Proxy,
   scoped_ptr<LayerTreeHostImpl> layer_tree_host_impl_;
   RendererCapabilities renderer_capabilities_for_main_thread_;
 
-  // Accessed from both threads.
-  scoped_ptr<Scheduler> scheduler_on_impl_thread_;
-  ProxyTimingHistory timing_history_;
-
   bool next_frame_is_newly_committed_frame_;
 
   bool inside_draw_;
-  bool defer_commits_;
-  bool commit_was_deferred_;
-  bool commit_requested_;
-
-  base::WeakPtrFactory<SingleThreadProxy> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SingleThreadProxy);
 };
diff --git a/cc/trees/thread_proxy.cc b/cc/trees/thread_proxy.cc
index ac8b4fd..a4a630e 100644
--- a/cc/trees/thread_proxy.cc
+++ b/cc/trees/thread_proxy.cc
@@ -25,7 +25,6 @@
 #include "cc/trees/blocking_task_runner.h"
 #include "cc/trees/layer_tree_host.h"
 #include "cc/trees/layer_tree_impl.h"
-#include "cc/trees/scoped_abort_remaining_swap_promises.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "ui/gfx/frame_time.h"
 
@@ -38,6 +37,19 @@ const double kSmoothnessTakesPriorityExpirationDelay = 0.25;
 
 unsigned int nextBeginFrameId = 0;
 
+class SwapPromiseChecker {
+ public:
+  explicit SwapPromiseChecker(LayerTreeHost* layer_tree_host)
+      : layer_tree_host_(layer_tree_host) {}
+
+  ~SwapPromiseChecker() {
+    layer_tree_host_->BreakSwapPromises(SwapPromise::COMMIT_FAILS);
+  }
+
+ private:
+  LayerTreeHost* layer_tree_host_;
+};
+
 }  // namespace
 
 struct ThreadProxy::SchedulerStateRequest {
@@ -441,10 +453,9 @@ void ThreadProxy::SetNextCommitWaitsForActivation() {
 
 void ThreadProxy::SetDeferCommits(bool defer_commits) {
   DCHECK(IsMainThread());
-  if (main().defer_commits == defer_commits)
-    return;
-
+  DCHECK_NE(main().defer_commits, defer_commits);
   main().defer_commits = defer_commits;
+
   if (main().defer_commits)
     TRACE_EVENT_ASYNC_BEGIN0("cc", "ThreadProxy::SetDeferCommits", this);
   else
@@ -724,9 +735,9 @@ void ThreadProxy::BeginMainFrame(
   }
 
   // If the commit finishes, LayerTreeHost will transfer its swap promises to
-  // LayerTreeImpl. The destructor of ScopedSwapPromiseChecker aborts the
-  // remaining swap promises.
-  ScopedAbortRemainingSwapPromises swap_promise_checker(layer_tree_host());
+  // LayerTreeImpl. The destructor of SwapPromiseChecker checks LayerTressHost's
+  // swap promises.
+  SwapPromiseChecker swap_promise_checker(layer_tree_host());
 
   main().commit_requested = false;
   main().commit_request_sent_to_impl_thread = false;
diff --git a/chrome/browser/ui/views/menu_view_drag_and_drop_test.cc b/chrome/browser/ui/views/menu_view_drag_and_drop_test.cc
index 7fb4ec8..4e9c4ae 100644
--- a/chrome/browser/ui/views/menu_view_drag_and_drop_test.cc
+++ b/chrome/browser/ui/views/menu_view_drag_and_drop_test.cc
@@ -17,9 +17,8 @@ namespace {
 
 // Borrowed from chrome/browser/ui/views/bookmarks/bookmark_bar_view_test.cc,
 // since these are also disabled on Linux for drag and drop.
-// TODO(erg): Fix DND tests on linux_aura. http://crbug.com/163931
-// TODO(enne): Windows version has flaky timeouts.  http://crbug.com/401226
-#if defined(USE_AURA)
+// TODO(erg): Fix DND tests on linux_aura. crbug.com/163931
+#if defined(OS_LINUX) && defined(USE_AURA)
 #define MAYBE(x) DISABLED_##x
 #else
 #define MAYBE(x) x
diff --git a/content/browser/renderer_host/compositor_impl_android.cc b/content/browser/renderer_host/compositor_impl_android.cc
index 13b0735..3ca74a2 100644
--- a/content/browser/renderer_host/compositor_impl_android.cc
+++ b/content/browser/renderer_host/compositor_impl_android.cc
@@ -314,6 +314,7 @@ void CompositorImpl::Composite(CompositingTrigger trigger) {
   // animation updates that will already be reflected in the current frame
   // we are about to draw.
   ignore_schedule_composite_ = true;
+  client_->Layout();
 
   const base::TimeTicks frame_time = gfx::FrameTime::Now();
   if (needs_animate_) {
@@ -425,6 +426,7 @@ void CompositorImpl::SetVisible(bool visible) {
   } else if (!host_) {
     DCHECK(!WillComposite());
     needs_composite_ = false;
+    needs_animate_ = false;
     pending_swapbuffers_ = 0;
     cc::LayerTreeSettings settings;
     settings.refresh_rate = 60.0;
@@ -439,8 +441,6 @@ void CompositorImpl::SetVisible(bool visible) {
         command_line->HasSwitch(cc::switches::kEnableGpuBenchmarking));
     settings.initial_debug_state.show_fps_counter =
         command_line->HasSwitch(cc::switches::kUIShowFPSCounter);
-    // TODO(enne): Update this this compositor to use the scheduler.
-    settings.single_thread_proxy_scheduler = false;
 
     host_ = cc::LayerTreeHost::CreateSingleThreaded(
         this,
@@ -523,9 +523,10 @@ CreateGpuProcessViewContext(
 }
 
 void CompositorImpl::Layout() {
-  ignore_schedule_composite_ = true;
+  // TODO: If we get this callback from the SingleThreadProxy, we need
+  // to stop calling it ourselves in CompositorImpl::Composite().
+  NOTREACHED();
   client_->Layout();
-  ignore_schedule_composite_ = false;
 }
 
 scoped_ptr<cc::OutputSurface> CompositorImpl::CreateOutputSurface(
@@ -574,6 +575,7 @@ void CompositorImpl::ScheduleComposite() {
 }
 
 void CompositorImpl::ScheduleAnimation() {
+  DCHECK(!needs_animate_ || needs_composite_);
   DCHECK(!needs_composite_ || WillComposite());
   needs_animate_ = true;
 
@@ -603,7 +605,6 @@ void CompositorImpl::DidAbortSwapBuffers() {
   // This really gets called only once from
   // SingleThreadProxy::DidLoseOutputSurfaceOnImplThread() when the
   // context was lost.
-  ScheduleComposite();
   client_->OnSwapBuffersCompleted(0);
 }
 
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index 0fc9e87..43bbe32 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -246,10 +246,6 @@ const char kDisableSetuidSandbox[]          = "disable-setuid-sandbox";
 // Disable shared workers.
 const char kDisableSharedWorkers[]          = "disable-shared-workers";
 
-// For tests, disable single thread scheduler and only manually composite.
-const char kDisableSingleThreadProxyScheduler[] =
-    "disable-single-thread-proxy-scheduler";
-
 // Disable smooth scrolling for testing.
 const char kDisableSmoothScrolling[]        = "disable-smooth-scrolling";
 
diff --git a/content/public/common/content_switches.h b/content/public/common/content_switches.h
index 0477a6a..69add0a 100644
--- a/content/public/common/content_switches.h
+++ b/content/public/common/content_switches.h
@@ -79,7 +79,6 @@ CONTENT_EXPORT extern const char kDisableSeccompFilterSandbox[];
 extern const char kDisableSessionStorage[];
 CONTENT_EXPORT extern const char kDisableSetuidSandbox[];
 CONTENT_EXPORT extern const char kDisableSharedWorkers[];
-CONTENT_EXPORT extern const char kDisableSingleThreadProxyScheduler[];
 CONTENT_EXPORT extern const char kDisableSmoothScrolling[];
 CONTENT_EXPORT extern const char kDisableSoftwareRasterizer[];
 CONTENT_EXPORT extern const char kDisableThreadedCompositing[];
diff --git a/content/renderer/gpu/render_widget_compositor.cc b/content/renderer/gpu/render_widget_compositor.cc
index baf1ac1..23230ee 100644
--- a/content/renderer/gpu/render_widget_compositor.cc
+++ b/content/renderer/gpu/render_widget_compositor.cc
@@ -277,8 +277,6 @@ scoped_ptr<RenderWidgetCompositor> RenderWidgetCompositor::Create(
       cmd->HasSwitch(cc::switches::kEnablePinchVirtualViewport);
   settings.allow_antialiasing &=
       !cmd->HasSwitch(cc::switches::kDisableCompositedAntialiasing);
-  settings.single_thread_proxy_scheduler =
-      !cmd->HasSwitch(switches::kDisableSingleThreadProxyScheduler);
 
   // These flags should be mirrored by UI versions in ui/compositor/.
   settings.initial_debug_state.show_debug_borders =
@@ -411,6 +409,7 @@ scoped_ptr<RenderWidgetCompositor> RenderWidgetCompositor::Create(
 RenderWidgetCompositor::RenderWidgetCompositor(RenderWidget* widget,
                                                bool threaded)
     : threaded_(threaded),
+      suppress_schedule_composite_(false),
       widget_(widget) {
 }
 
@@ -421,10 +420,27 @@ RenderWidgetCompositor::GetInputHandler() {
   return layer_tree_host_->GetInputHandler();
 }
 
+void RenderWidgetCompositor::SetSuppressScheduleComposite(bool suppress) {
+  if (suppress_schedule_composite_ == suppress)
+    return;
+
+  if (suppress)
+    TRACE_EVENT_ASYNC_BEGIN0(
+        "gpu", "RenderWidgetCompositor::SetSuppressScheduleComposite", this);
+  else
+    TRACE_EVENT_ASYNC_END0(
+        "gpu", "RenderWidgetCompositor::SetSuppressScheduleComposite", this);
+  suppress_schedule_composite_ = suppress;
+}
+
 bool RenderWidgetCompositor::BeginMainFrameRequested() const {
   return layer_tree_host_->BeginMainFrameRequested();
 }
 
+void RenderWidgetCompositor::UpdateAnimations(base::TimeTicks time) {
+  layer_tree_host_->UpdateClientAnimations(time);
+}
+
 void RenderWidgetCompositor::SetNeedsDisplayOnAllLayers() {
   layer_tree_host_->SetNeedsDisplayOnAllLayers();
 }
@@ -533,10 +549,7 @@ void RenderWidgetCompositor::Initialize(cc::LayerTreeSettings settings) {
 }
 
 void RenderWidgetCompositor::setSurfaceReady() {
-  // In tests without a RenderThreadImpl, don't set ready as this kicks
-  // off creating output surfaces that the test can't create.
-  if (RenderThreadImpl::current())
-    layer_tree_host_->SetLayerTreeHostClientReady();
+  layer_tree_host_->SetLayerTreeHostClientReady();
 }
 
 void RenderWidgetCompositor::setRootLayer(const blink::WebLayer& layer) {
@@ -689,9 +702,9 @@ void RenderWidgetCompositor::compositeAndReadbackAsync(
       cc::CopyOutputRequest::CreateBitmapRequest(
           base::Bind(&CompositeAndReadbackAsyncCallback, callback));
   layer_tree_host_->root_layer()->RequestCopyOfOutput(request.Pass());
-
-  if (!threaded_ &&
-      !layer_tree_host_->settings().single_thread_proxy_scheduler) {
+  if (!threaded_) {
+    widget_->webwidget()->animate(0.0);
+    widget_->webwidget()->layout();
     layer_tree_host_->Composite(gfx::FrameTime::Now());
   }
 }
@@ -787,6 +800,11 @@ void RenderWidgetCompositor::DidCompleteSwapBuffers() {
     widget_->OnSwapBuffersComplete();
 }
 
+void RenderWidgetCompositor::ScheduleComposite() {
+  if (!suppress_schedule_composite_)
+    widget_->scheduleComposite();
+}
+
 void RenderWidgetCompositor::ScheduleAnimation() {
   widget_->scheduleAnimation();
 }
diff --git a/content/renderer/gpu/render_widget_compositor.h b/content/renderer/gpu/render_widget_compositor.h
index 79a03b4..e0541ec 100644
--- a/content/renderer/gpu/render_widget_compositor.h
+++ b/content/renderer/gpu/render_widget_compositor.h
@@ -44,7 +44,9 @@ class RenderWidgetCompositor : public blink::WebLayerTreeView,
   virtual ~RenderWidgetCompositor();
 
   const base::WeakPtr<cc::InputHandler>& GetInputHandler();
+  void SetSuppressScheduleComposite(bool suppress);
   bool BeginMainFrameRequested() const;
+  void UpdateAnimations(base::TimeTicks time);
   void SetNeedsDisplayOnAllLayers();
   void SetRasterizeOnlyVisibleContent();
   void UpdateTopControlsState(cc::TopControlsState constraints,
@@ -141,6 +143,7 @@ class RenderWidgetCompositor : public blink::WebLayerTreeView,
   virtual void RateLimitSharedMainThreadContext() OVERRIDE;
 
   // cc::LayerTreeHostSingleThreadClient implementation.
+  virtual void ScheduleComposite() OVERRIDE;
   virtual void ScheduleAnimation() OVERRIDE;
   virtual void DidPostSwapBuffers() OVERRIDE;
   virtual void DidAbortSwapBuffers() OVERRIDE;
@@ -151,6 +154,7 @@ class RenderWidgetCompositor : public blink::WebLayerTreeView,
   void Initialize(cc::LayerTreeSettings settings);
 
   bool threaded_;
+  bool suppress_schedule_composite_;
   RenderWidget* widget_;
   scoped_ptr<cc::LayerTreeHost> layer_tree_host_;
 };
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 7e7fb2d..10d87e1 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -393,7 +393,6 @@ RenderWidget::RenderWidget(blink::WebPopupType popup_type,
       handling_event_type_(WebInputEvent::Undefined),
       ignore_ack_for_mouse_move_from_debugger_(false),
       closing_(false),
-      host_closing_(false),
       is_swapped_out_(swapped_out),
       input_method_is_active_(false),
       text_input_type_(ui::TEXT_INPUT_TYPE_NONE),
@@ -1202,8 +1201,6 @@ void RenderWidget::AutoResizeCompositor()  {
 }
 
 void RenderWidget::initializeLayerTreeView() {
-  DCHECK(!host_closing_);
-
   compositor_ =
       RenderWidgetCompositor::Create(this, IsThreadedCompositingEnabled());
   compositor_->setViewportSize(size_, physical_backing_size_);
@@ -1211,20 +1208,20 @@ void RenderWidget::initializeLayerTreeView() {
     StartCompositor();
 }
 
-void RenderWidget::DestroyLayerTreeView() {
-  // Always send this notification to prevent new layer tree views from
-  // being created, even if one hasn't been created yet.
-  webwidget_->willCloseLayerTreeView();
-  compositor_.reset();
-}
-
 blink::WebLayerTreeView* RenderWidget::layerTreeView() {
   return compositor_.get();
 }
 
+void RenderWidget::suppressCompositorScheduling(bool enable) {
+  if (compositor_)
+    compositor_->SetSuppressScheduleComposite(enable);
+}
+
 void RenderWidget::willBeginCompositorFrame() {
   TRACE_EVENT0("gpu", "RenderWidget::willBeginCompositorFrame");
 
+  DCHECK(RenderThreadImpl::current()->compositor_message_loop_proxy().get());
+
   // The following two can result in further layout and possibly
   // enable GPU acceleration so they need to be called before any painting
   // is done.
@@ -1381,12 +1378,6 @@ void RenderWidget::didBlur() {
 }
 
 void RenderWidget::DoDeferredClose() {
-  // No more compositing is possible.  This prevents shutdown races between
-  // previously posted CreateOutputSurface tasks and the host being unable to
-  // create them because the close message was handled.
-  DestroyLayerTreeView();
-  // Also prevent new compositors from being created.
-  host_closing_ = true;
   Send(new ViewHostMsg_Close(routing_id_));
 }
 
@@ -1427,7 +1418,8 @@ void RenderWidget::QueueSyntheticGesture(
 void RenderWidget::Close() {
   screen_metrics_emulator_.reset();
   if (webwidget_) {
-    DestroyLayerTreeView();
+    webwidget_->willCloseLayerTreeView();
+    compositor_.reset();
     webwidget_->close();
     webwidget_ = NULL;
   }
diff --git a/content/renderer/render_widget.h b/content/renderer/render_widget.h
index 22612a5..bd97588 100644
--- a/content/renderer/render_widget.h
+++ b/content/renderer/render_widget.h
@@ -142,6 +142,7 @@ class CONTENT_EXPORT RenderWidget
   virtual bool Send(IPC::Message* msg) OVERRIDE;
 
   // blink::WebWidgetClient
+  virtual void suppressCompositorScheduling(bool enable);
   virtual void willBeginCompositorFrame();
   virtual void didAutoResize(const blink::WebSize& new_size);
   virtual void initializeLayerTreeView();
@@ -172,9 +173,6 @@ class CONTENT_EXPORT RenderWidget
   // Begins the compositor's scheduler to start producing frames.
   void StartCompositor();
 
-  // Stop compositing.
-  void DestroyLayerTreeView();
-
   // Called when a plugin is moved.  These events are queued up and sent with
   // the next paint or scroll message to the host.
   void SchedulePluginMove(const WebPluginGeometry& move);
@@ -626,9 +624,6 @@ class CONTENT_EXPORT RenderWidget
   // be sent, except for a Close.
   bool closing_;
 
-  // True if it is known that the host is in the process of being shut down.
-  bool host_closing_;
-
   // Whether this RenderWidget is currently swapped out, such that the view is
   // being rendered by another process.  If all RenderWidgets in a process are
   // swapped out, the process can exit.
diff --git a/content/shell/renderer/test_runner/web_test_proxy.cc b/content/shell/renderer/test_runner/web_test_proxy.cc
index 18086de..7e36976 100644
--- a/content/shell/renderer/test_runner/web_test_proxy.cc
+++ b/content/shell/renderer/test_runner/web_test_proxy.cc
@@ -7,11 +7,9 @@
 #include <cctype>
 
 #include "base/callback_helpers.h"
-#include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
-#include "content/public/common/content_switches.h"
 #include "content/shell/renderer/test_runner/TestPlugin.h"
 #include "content/shell/renderer/test_runner/WebTestDelegate.h"
 #include "content/shell/renderer/test_runner/WebTestInterfaces.h"
@@ -315,10 +313,6 @@ WebTestProxyBase::WebTestProxyBase()
       web_widget_(NULL),
       spellcheck_(new SpellCheckClient(this)),
       chooser_count_(0) {
-  // TODO(enne): using the scheduler introduces additional composite steps
-  // that create flakiness.  This should go away eventually.
-  base::CommandLine::ForCurrentProcess()->AppendSwitch(
-      switches::kDisableSingleThreadProxyScheduler);
   Reset();
 }
 
diff --git a/content/test/web_layer_tree_view_impl_for_testing.h b/content/test/web_layer_tree_view_impl_for_testing.h
index 730c210..13d6ee4 100644
--- a/content/test/web_layer_tree_view_impl_for_testing.h
+++ b/content/test/web_layer_tree_view_impl_for_testing.h
@@ -80,6 +80,8 @@ class WebLayerTreeViewImplForTesting
   virtual void DidCompleteSwapBuffers() OVERRIDE {}
 
   // cc::LayerTreeHostSingleThreadClient implementation.
+  virtual void ScheduleComposite() OVERRIDE {}
+  virtual void ScheduleAnimation() OVERRIDE {}
   virtual void DidPostSwapBuffers() OVERRIDE {}
   virtual void DidAbortSwapBuffers() OVERRIDE {}
 
diff --git a/ui/compositor/compositor.cc b/ui/compositor/compositor.cc
index 6be8530..fce83d6 100644
--- a/ui/compositor/compositor.cc
+++ b/ui/compositor/compositor.cc
@@ -61,6 +61,12 @@ void CompositorLock::CancelLock() {
   compositor_ = NULL;
 }
 
+}  // namespace ui
+
+namespace {}  // namespace
+
+namespace ui {
+
 Compositor::Compositor(gfx::AcceleratedWidget widget,
                        ui::ContextFactory* context_factory,
                        scoped_refptr<base::SingleThreadTaskRunner> task_runner)
@@ -71,9 +77,16 @@ Compositor::Compositor(gfx::AcceleratedWidget widget,
       task_runner_(task_runner),
       vsync_manager_(new CompositorVSyncManager()),
       device_scale_factor_(0.0f),
+      last_started_frame_(0),
+      last_ended_frame_(0),
       disable_schedule_composite_(false),
       compositor_lock_(NULL),
-      layer_animator_collection_(this) {
+      defer_draw_scheduling_(false),
+      waiting_on_compositing_end_(false),
+      draw_on_compositing_end_(false),
+      swap_state_(SWAP_NONE),
+      layer_animator_collection_(this),
+      schedule_draw_factory_(this) {
   root_web_layer_ = cc::Layer::Create();
 
   CommandLine* command_line = CommandLine::ForCurrentProcess();
@@ -162,7 +175,14 @@ Compositor::~Compositor() {
 }
 
 void Compositor::ScheduleDraw() {
-  host_->SetNeedsCommit();
+  if (compositor_thread_loop_) {
+    host_->SetNeedsCommit();
+  } else if (!defer_draw_scheduling_) {
+    defer_draw_scheduling_ = true;
+    task_runner_->PostTask(
+        FROM_HERE,
+        base::Bind(&Compositor::Draw, schedule_draw_factory_.GetWeakPtr()));
+  }
 }
 
 void Compositor::SetRootLayer(Layer* root_layer) {
@@ -183,19 +203,42 @@ void Compositor::SetHostHasTransparentBackground(
   host_->set_has_transparent_background(host_has_transparent_background);
 }
 
+void Compositor::Draw() {
+  DCHECK(!compositor_thread_loop_);
+
+  defer_draw_scheduling_ = false;
+  if (waiting_on_compositing_end_) {
+    draw_on_compositing_end_ = true;
+    return;
+  }
+  if (!root_layer_)
+    return;
+
+  TRACE_EVENT_ASYNC_BEGIN0("ui", "Compositor::Draw", last_started_frame_ + 1);
+
+  DCHECK_NE(swap_state_, SWAP_POSTED);
+  swap_state_ = SWAP_NONE;
+
+  waiting_on_compositing_end_ = true;
+  last_started_frame_++;
+  if (!IsLocked()) {
+    // TODO(nduca): Temporary while compositor calls
+    // compositeImmediately() directly.
+    base::TimeTicks now = gfx::FrameTime::Now();
+    Animate(now);
+    Layout();
+    host_->Composite(now);
+  }
+  if (swap_state_ == SWAP_NONE)
+    NotifyEnd();
+}
+
 void Compositor::ScheduleFullRedraw() {
-  // TODO(enne): Some callers (mac) call this function expecting that it
-  // will also commit.  This should probably just redraw the screen
-  // from damage and not commit.  ScheduleDraw/ScheduleRedraw need
-  // better names.
   host_->SetNeedsRedraw();
-  host_->SetNeedsCommit();
 }
 
 void Compositor::ScheduleRedrawRect(const gfx::Rect& damage_rect) {
-  // TODO(enne): Make this not commit.  See ScheduleFullRedraw.
   host_->SetNeedsRedrawRect(damage_rect);
-  host_->SetNeedsCommit();
 }
 
 void Compositor::FinishAllRendering() {
@@ -302,30 +345,45 @@ void Compositor::DidCommit() {
 }
 
 void Compositor::DidCommitAndDrawFrame() {
+  base::TimeTicks start_time = gfx::FrameTime::Now();
+  FOR_EACH_OBSERVER(CompositorObserver,
+                    observer_list_,
+                    OnCompositingStarted(this, start_time));
 }
 
 void Compositor::DidCompleteSwapBuffers() {
-  // DidPostSwapBuffers is a SingleThreadProxy-only feature.  Synthetically
-  // generate OnCompositingStarted messages for the threaded case so that
-  // OnCompositingStarted/OnCompositingEnded messages match.
   if (compositor_thread_loop_) {
-    base::TimeTicks start_time = gfx::FrameTime::Now();
-    FOR_EACH_OBSERVER(CompositorObserver,
-                      observer_list_,
-                      OnCompositingStarted(this, start_time));
+    NotifyEnd();
+  } else {
+    DCHECK_EQ(swap_state_, SWAP_POSTED);
+    NotifyEnd();
+    swap_state_ = SWAP_COMPLETED;
   }
-  FOR_EACH_OBSERVER(
-      CompositorObserver, observer_list_, OnCompositingEnded(this));
+}
+
+void Compositor::ScheduleComposite() {
+  if (!disable_schedule_composite_)
+    ScheduleDraw();
+}
+
+void Compositor::ScheduleAnimation() {
+  ScheduleComposite();
 }
 
 void Compositor::DidPostSwapBuffers() {
-  base::TimeTicks start_time = gfx::FrameTime::Now();
-  FOR_EACH_OBSERVER(CompositorObserver,
-                    observer_list_,
-                    OnCompositingStarted(this, start_time));
+  DCHECK(!compositor_thread_loop_);
+  DCHECK_EQ(swap_state_, SWAP_NONE);
+  swap_state_ = SWAP_POSTED;
 }
 
 void Compositor::DidAbortSwapBuffers() {
+  if (!compositor_thread_loop_) {
+    if (swap_state_ == SWAP_POSTED) {
+      NotifyEnd();
+      swap_state_ = SWAP_COMPLETED;
+    }
+  }
+
   FOR_EACH_OBSERVER(CompositorObserver,
                     observer_list_,
                     OnCompositingAborted(this));
@@ -343,7 +401,8 @@ void Compositor::SetLayerTreeDebugState(
 scoped_refptr<CompositorLock> Compositor::GetCompositorLock() {
   if (!compositor_lock_) {
     compositor_lock_ = new CompositorLock(this);
-    host_->SetDeferCommits(true);
+    if (compositor_thread_loop_)
+      host_->SetDeferCommits(true);
     FOR_EACH_OBSERVER(CompositorObserver,
                       observer_list_,
                       OnCompositingLockStateChanged(this));
@@ -354,7 +413,8 @@ scoped_refptr<CompositorLock> Compositor::GetCompositorLock() {
 void Compositor::UnlockCompositor() {
   DCHECK(compositor_lock_);
   compositor_lock_ = NULL;
-  host_->SetDeferCommits(false);
+  if (compositor_thread_loop_)
+    host_->SetDeferCommits(false);
   FOR_EACH_OBSERVER(CompositorObserver,
                     observer_list_,
                     OnCompositingLockStateChanged(this));
@@ -365,4 +425,20 @@ void Compositor::CancelCompositorLock() {
     compositor_lock_->CancelLock();
 }
 
+void Compositor::NotifyEnd() {
+  last_ended_frame_++;
+  TRACE_EVENT_ASYNC_END0("ui", "Compositor::Draw", last_ended_frame_);
+  waiting_on_compositing_end_ = false;
+  if (draw_on_compositing_end_) {
+    draw_on_compositing_end_ = false;
+
+    // Call ScheduleDraw() instead of Draw() in order to allow other
+    // CompositorObservers to be notified before starting another
+    // draw cycle.
+    ScheduleDraw();
+  }
+  FOR_EACH_OBSERVER(
+      CompositorObserver, observer_list_, OnCompositingEnded(this));
+}
+
 }  // namespace ui
diff --git a/ui/compositor/compositor.h b/ui/compositor/compositor.h
index b2d2779..0e4ac8a 100644
--- a/ui/compositor/compositor.h
+++ b/ui/compositor/compositor.h
@@ -24,6 +24,8 @@
 #include "ui/gfx/size.h"
 #include "ui/gfx/vector2d.h"
 
+class SkBitmap;
+
 namespace base {
 class MessageLoopProxy;
 class RunLoop;
@@ -157,6 +159,9 @@ class COMPOSITOR_EXPORT Compositor
   // compositing layers on.
   float device_scale_factor() const { return device_scale_factor_; }
 
+  // Draws the scene created by the layer tree and any visual effects.
+  void Draw();
+
   // Where possible, draws are scissored to a damage region calculated from
   // changes to layer properties.  This bypasses that and indicates that
   // the whole frame needs to be drawn.
@@ -229,9 +234,14 @@ class COMPOSITOR_EXPORT Compositor
   virtual void DidCompleteSwapBuffers() OVERRIDE;
 
   // cc::LayerTreeHostSingleThreadClient implementation.
+  virtual void ScheduleComposite() OVERRIDE;
+  virtual void ScheduleAnimation() OVERRIDE;
   virtual void DidPostSwapBuffers() OVERRIDE;
   virtual void DidAbortSwapBuffers() OVERRIDE;
 
+  int last_started_frame() { return last_started_frame_; }
+  int last_ended_frame() { return last_ended_frame_; }
+
   bool IsLocked() { return compositor_lock_ != NULL; }
 
   const cc::LayerTreeDebugState& GetLayerTreeDebugState() const;
@@ -251,6 +261,9 @@ class COMPOSITOR_EXPORT Compositor
   // Called to release any pending CompositorLock
   void CancelCompositorLock();
 
+  // Notifies the compositor that compositing is complete.
+  void NotifyEnd();
+
   gfx::Size size_;
 
   ui::ContextFactory* context_factory_;
@@ -281,8 +294,19 @@ class COMPOSITOR_EXPORT Compositor
 
   CompositorLock* compositor_lock_;
 
+  // Prevent more than one draw from being scheduled.
+  bool defer_draw_scheduling_;
+
+  // Used to prevent Draw()s while a composite is in progress.
+  bool waiting_on_compositing_end_;
+  bool draw_on_compositing_end_;
+  enum SwapState { SWAP_NONE, SWAP_POSTED, SWAP_COMPLETED };
+  SwapState swap_state_;
+
   LayerAnimatorCollection layer_animator_collection_;
 
+  base::WeakPtrFactory<Compositor> schedule_draw_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(Compositor);
 };
 
diff --git a/ui/compositor/layer_unittest.cc b/ui/compositor/layer_unittest.cc
index b5c473c..9cb80c4 100644
--- a/ui/compositor/layer_unittest.cc
+++ b/ui/compositor/layer_unittest.cc
@@ -126,7 +126,7 @@ class LayerWithRealCompositorTest : public testing::Test {
   void DrawTree(Layer* root) {
     GetCompositor()->SetRootLayer(root);
     GetCompositor()->ScheduleDraw();
-    WaitForSwap();
+    WaitForDraw();
   }
 
   bool ReadPixels(SkBitmap* bitmap) {
@@ -142,13 +142,11 @@ class LayerWithRealCompositorTest : public testing::Test {
 
     GetCompositor()->root_layer()->RequestCopyOfOutput(request.Pass());
 
-    // Wait for copy response.  The copy output request will get committed
-    // before the first draw, but may not be part of the first draw's frame.
-    // The second draw will perform the async copy request, post the callback.
-    // The second loop finishes before the callback is run, so a third
-    // loop is needed.
-    for (int i = 0; i < 3; i++) {
-      GetCompositor()->ScheduleFullRedraw();
+    // Wait for copy response.  This needs to wait as the compositor could
+    // be in the middle of a draw right now, and the commit with the
+    // copy output request may not be done on the first draw.
+    for (int i = 0; i < 2; i++) {
+      GetCompositor()->ScheduleDraw();
       WaitForDraw();
     }
 
@@ -162,13 +160,7 @@ class LayerWithRealCompositorTest : public testing::Test {
     return false;
   }
 
-  void WaitForDraw() {
-    ui::DrawWaiterForTest::WaitForCompositingStarted(GetCompositor());
-  }
-
-  void WaitForSwap() {
-    DrawWaiterForTest::WaitForCompositingEnded(GetCompositor());
-  }
+  void WaitForDraw() { ui::DrawWaiterForTest::Wait(GetCompositor()); }
 
   void WaitForCommit() {
     ui::DrawWaiterForTest::WaitForCommit(GetCompositor());
@@ -455,9 +447,7 @@ class LayerWithDelegateTest : public testing::Test {
     WaitForDraw();
   }
 
-  void WaitForDraw() {
-    DrawWaiterForTest::WaitForCompositingStarted(compositor());
-  }
+  void WaitForDraw() { DrawWaiterForTest::Wait(compositor()); }
 
   void WaitForCommit() {
     DrawWaiterForTest::WaitForCommit(compositor());
@@ -951,25 +941,25 @@ TEST_F(LayerWithRealCompositorTest, CompositorObservers) {
   // Moving, but not resizing, a layer should alert the observers.
   observer.Reset();
   l2->SetBounds(gfx::Rect(0, 0, 350, 350));
-  WaitForSwap();
+  WaitForDraw();
   EXPECT_TRUE(observer.notified());
 
   // So should resizing a layer.
   observer.Reset();
   l2->SetBounds(gfx::Rect(0, 0, 400, 400));
-  WaitForSwap();
+  WaitForDraw();
   EXPECT_TRUE(observer.notified());
 
   // Opacity changes should alert the observers.
   observer.Reset();
   l2->SetOpacity(0.5f);
-  WaitForSwap();
+  WaitForDraw();
   EXPECT_TRUE(observer.notified());
 
   // So should setting the opacity back.
   observer.Reset();
   l2->SetOpacity(1.0f);
-  WaitForSwap();
+  WaitForDraw();
   EXPECT_TRUE(observer.notified());
 
   // Setting the transform of a layer should alert the observers.
@@ -979,7 +969,7 @@ TEST_F(LayerWithRealCompositorTest, CompositorObservers) {
   transform.Rotate(90.0);
   transform.Translate(-200.0, -200.0);
   l2->SetTransform(transform);
-  WaitForSwap();
+  WaitForDraw();
   EXPECT_TRUE(observer.notified());
 
   // A change resulting in an aborted swap buffer should alert the observer
@@ -987,7 +977,7 @@ TEST_F(LayerWithRealCompositorTest, CompositorObservers) {
   observer.Reset();
   l2->SetOpacity(0.1f);
   GetCompositor()->DidAbortSwapBuffers();
-  WaitForSwap();
+  WaitForDraw();
   EXPECT_TRUE(observer.notified());
   EXPECT_TRUE(observer.aborted());
 
@@ -996,7 +986,7 @@ TEST_F(LayerWithRealCompositorTest, CompositorObservers) {
   // Opacity changes should no longer alert the removed observer.
   observer.Reset();
   l2->SetOpacity(0.5f);
-  WaitForSwap();
+  WaitForDraw();
 
   EXPECT_FALSE(observer.notified());
 }
diff --git a/ui/compositor/test/draw_waiter_for_test.cc b/ui/compositor/test/draw_waiter_for_test.cc
index f256ecc..7687d66 100644
--- a/ui/compositor/test/draw_waiter_for_test.cc
+++ b/ui/compositor/test/draw_waiter_for_test.cc
@@ -9,24 +9,20 @@
 namespace ui {
 
 // static
-void DrawWaiterForTest::WaitForCompositingStarted(Compositor* compositor) {
-  DrawWaiterForTest waiter(WAIT_FOR_COMPOSITING_STARTED);
-  waiter.WaitImpl(compositor);
-}
-
-void DrawWaiterForTest::WaitForCompositingEnded(Compositor* compositor) {
-  DrawWaiterForTest waiter(WAIT_FOR_COMPOSITING_ENDED);
+void DrawWaiterForTest::Wait(Compositor* compositor) {
+  DrawWaiterForTest waiter;
+  waiter.wait_for_commit_ = false;
   waiter.WaitImpl(compositor);
 }
 
 // static
 void DrawWaiterForTest::WaitForCommit(Compositor* compositor) {
-  DrawWaiterForTest waiter(WAIT_FOR_COMMIT);
+  DrawWaiterForTest waiter;
+  waiter.wait_for_commit_ = true;
   waiter.WaitImpl(compositor);
 }
 
-DrawWaiterForTest::DrawWaiterForTest(WaitEvent wait_event)
-    : wait_event_(wait_event) {
+DrawWaiterForTest::DrawWaiterForTest() {
 }
 
 DrawWaiterForTest::~DrawWaiterForTest() {}
@@ -39,18 +35,16 @@ void DrawWaiterForTest::WaitImpl(Compositor* compositor) {
 }
 
 void DrawWaiterForTest::OnCompositingDidCommit(Compositor* compositor) {
-  if (wait_event_ == WAIT_FOR_COMMIT)
+  if (wait_for_commit_)
     wait_run_loop_->Quit();
 }
 
 void DrawWaiterForTest::OnCompositingStarted(Compositor* compositor,
                                              base::TimeTicks start_time) {
-  if (wait_event_ == WAIT_FOR_COMPOSITING_STARTED)
-    wait_run_loop_->Quit();
 }
 
 void DrawWaiterForTest::OnCompositingEnded(Compositor* compositor) {
-  if (wait_event_ == WAIT_FOR_COMPOSITING_ENDED)
+  if (!wait_for_commit_)
     wait_run_loop_->Quit();
 }
 
diff --git a/ui/compositor/test/draw_waiter_for_test.h b/ui/compositor/test/draw_waiter_for_test.h
index e1d63ff..051c58f 100644
--- a/ui/compositor/test/draw_waiter_for_test.h
+++ b/ui/compositor/test/draw_waiter_for_test.h
@@ -20,22 +20,13 @@ class DrawWaiterForTest : public CompositorObserver {
   // Waits for a draw to be issued by the compositor. If the test times out
   // here, there may be a logic error in the compositor code causing it
   // not to draw.
-  static void WaitForCompositingStarted(Compositor* compositor);
-
-  // Waits for a swap to be completed from the compositor.
-  static void WaitForCompositingEnded(Compositor* compositor);
+  static void Wait(Compositor* compositor);
 
   // Waits for a commit instead of a draw.
   static void WaitForCommit(Compositor* compositor);
 
  private:
-  enum WaitEvent {
-    WAIT_FOR_COMMIT,
-    WAIT_FOR_COMPOSITING_STARTED,
-    WAIT_FOR_COMPOSITING_ENDED,
-  };
-
-  DrawWaiterForTest(WaitEvent wait_event);
+  DrawWaiterForTest();
   virtual ~DrawWaiterForTest();
 
   void WaitImpl(Compositor* compositor);
@@ -50,7 +41,7 @@ class DrawWaiterForTest : public CompositorObserver {
 
   scoped_ptr<base::RunLoop> wait_run_loop_;
 
-  WaitEvent wait_event_;
+  bool wait_for_commit_;
 
   DISALLOW_COPY_AND_ASSIGN(DrawWaiterForTest);
 };
diff --git a/ui/compositor/test/test_compositor_host_mac.mm b/ui/compositor/test/test_compositor_host_mac.mm
index 7201fde..8d533d0 100644
--- a/ui/compositor/test/test_compositor_host_mac.mm
+++ b/ui/compositor/test/test_compositor_host_mac.mm
@@ -40,7 +40,7 @@
 
 - (void)drawRect:(NSRect)rect {
   DCHECK(compositor_) << "Drawing with no compositor set.";
-  compositor_->ScheduleFullRedraw();
+  compositor_->Draw();
 }
 @end
 
diff --git a/ui/compositor/test/test_compositor_host_ozone.cc b/ui/compositor/test/test_compositor_host_ozone.cc
index 903c3b6..1c4b0cc 100644
--- a/ui/compositor/test/test_compositor_host_ozone.cc
+++ b/ui/compositor/test/test_compositor_host_ozone.cc
@@ -27,6 +27,8 @@ class TestCompositorHostOzone : public TestCompositorHost {
   virtual void Show() OVERRIDE;
   virtual ui::Compositor* GetCompositor() OVERRIDE;
 
+  void Draw();
+
   gfx::Rect bounds_;
 
   ui::ContextFactory* context_factory_;
@@ -62,6 +64,11 @@ ui::Compositor* TestCompositorHostOzone::GetCompositor() {
   return compositor_.get();
 }
 
+void TestCompositorHostOzone::Draw() {
+  if (compositor_.get())
+    compositor_->Draw();
+}
+
 // static
 TestCompositorHost* TestCompositorHost::Create(
     const gfx::Rect& bounds,
diff --git a/ui/compositor/test/test_compositor_host_win.cc b/ui/compositor/test/test_compositor_host_win.cc
index 80db4ae..9c732f6 100644
--- a/ui/compositor/test/test_compositor_host_win.cc
+++ b/ui/compositor/test/test_compositor_host_win.cc
@@ -42,7 +42,7 @@ class TestCompositorHostWin : public TestCompositorHost,
   CR_END_MSG_MAP()
 
   void OnPaint(HDC dc) {
-    compositor_->ScheduleFullRedraw();
+    compositor_->Draw();
     ValidateRect(hwnd(), NULL);
   }
 
diff --git a/ui/compositor/test/test_compositor_host_x11.cc b/ui/compositor/test/test_compositor_host_x11.cc
index 1c3f674..9b2d265 100644
--- a/ui/compositor/test/test_compositor_host_x11.cc
+++ b/ui/compositor/test/test_compositor_host_x11.cc
@@ -30,6 +30,8 @@ class TestCompositorHostX11 : public TestCompositorHost {
   virtual void Show() OVERRIDE;
   virtual ui::Compositor* GetCompositor() OVERRIDE;
 
+  void Draw();
+
   gfx::Rect bounds_;
 
   ui::ContextFactory* context_factory_;
@@ -83,6 +85,11 @@ ui::Compositor* TestCompositorHostX11::GetCompositor() {
   return compositor_.get();
 }
 
+void TestCompositorHostX11::Draw() {
+  if (compositor_.get())
+    compositor_->Draw();
+}
+
 // static
 TestCompositorHost* TestCompositorHost::Create(
     const gfx::Rect& bounds,
diff --git a/ui/snapshot/snapshot_aura_unittest.cc b/ui/snapshot/snapshot_aura_unittest.cc
index 018394b..5fe05a8 100644
--- a/ui/snapshot/snapshot_aura_unittest.cc
+++ b/ui/snapshot/snapshot_aura_unittest.cc
@@ -115,8 +115,7 @@ class SnapshotAuraTest : public testing::Test {
 
   void WaitForDraw() {
     helper_->host()->compositor()->ScheduleDraw();
-    ui::DrawWaiterForTest::WaitForCompositingEnded(
-        helper_->host()->compositor());
+    ui::DrawWaiterForTest::Wait(helper_->host()->compositor());
   }
 
   void SetupTestWindow(const gfx::Rect& window_bounds) {
diff --git a/ui/views/view_unittest.cc b/ui/views/view_unittest.cc
index 87164b0..c4e6dcb 100644
--- a/ui/views/view_unittest.cc
+++ b/ui/views/view_unittest.cc
@@ -3087,23 +3087,20 @@ TEST_F(ViewLayerTest, DontPaintChildrenWithLayers) {
   widget()->SetContentsView(content_view);
   content_view->SetPaintToLayer(true);
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
   GetRootLayer()->SchedulePaint(gfx::Rect(0, 0, 10, 10));
   content_view->set_painted(false);
   // content_view no longer has a dirty rect. Paint from the root and make sure
   // PaintTrackingView isn't painted.
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
   EXPECT_FALSE(content_view->painted());
 
   // Make content_view have a dirty rect, paint the layers and make sure
   // PaintTrackingView is painted.
   content_view->layer()->SchedulePaint(gfx::Rect(0, 0, 10, 10));
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
   EXPECT_TRUE(content_view->painted());
 }
 
@@ -3343,15 +3340,13 @@ TEST_F(ViewLayerTest, BoundsTreePaintUpdatesCullSet) {
   // Schedule a full-view paint to get everyone's rectangles updated.
   test_view->SchedulePaintInRect(test_view->bounds());
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
 
   // Now we have test_view - v1 - v2. Damage to only test_view should only
   // return root_view and test_view.
   test_view->SchedulePaintInRect(gfx::Rect(0, 0, 1, 1));
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
   EXPECT_EQ(2U, test_view->last_cull_set_.size());
   EXPECT_EQ(1U, test_view->last_cull_set_.count(widget()->GetRootView()));
   EXPECT_EQ(1U, test_view->last_cull_set_.count(test_view));
@@ -3359,8 +3354,7 @@ TEST_F(ViewLayerTest, BoundsTreePaintUpdatesCullSet) {
   // Damage to v1 only should only return root_view, test_view, and v1.
   test_view->SchedulePaintInRect(gfx::Rect(11, 16, 1, 1));
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
   EXPECT_EQ(3U, test_view->last_cull_set_.size());
   EXPECT_EQ(1U, test_view->last_cull_set_.count(widget()->GetRootView()));
   EXPECT_EQ(1U, test_view->last_cull_set_.count(test_view));
@@ -3370,8 +3364,7 @@ TEST_F(ViewLayerTest, BoundsTreePaintUpdatesCullSet) {
   // on call to TestView::Paint(), along with the widget root view.
   test_view->SchedulePaintInRect(gfx::Rect(31, 49, 1, 1));
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
   EXPECT_EQ(4U, test_view->last_cull_set_.size());
   EXPECT_EQ(1U, test_view->last_cull_set_.count(widget()->GetRootView()));
   EXPECT_EQ(1U, test_view->last_cull_set_.count(test_view));
@@ -3398,15 +3391,13 @@ TEST_F(ViewLayerTest, BoundsTreeWithRTL) {
   // Schedule a full-view paint to get everyone's rectangles updated.
   test_view->SchedulePaintInRect(test_view->bounds());
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
 
   // Damage to the right side of the parent view should touch both child views.
   gfx::Rect rtl_damage(test_view->bounds().width() - 16, 18, 1, 1);
   test_view->SchedulePaintInRect(rtl_damage);
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
   EXPECT_EQ(4U, test_view->last_cull_set_.size());
   EXPECT_EQ(1U, test_view->last_cull_set_.count(widget()->GetRootView()));
   EXPECT_EQ(1U, test_view->last_cull_set_.count(test_view));
@@ -3418,8 +3409,7 @@ TEST_F(ViewLayerTest, BoundsTreeWithRTL) {
   gfx::Rect ltr_damage(16, 18, 1, 1);
   test_view->SchedulePaintInRect(ltr_damage);
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
   EXPECT_EQ(2U, test_view->last_cull_set_.size());
   EXPECT_EQ(1U, test_view->last_cull_set_.count(widget()->GetRootView()));
   EXPECT_EQ(1U, test_view->last_cull_set_.count(test_view));
@@ -3443,21 +3433,18 @@ TEST_F(ViewLayerTest, BoundsTreeSetBoundsChangesCullSet) {
   // Schedule a full-view paint to get everyone's rectangles updated.
   test_view->SchedulePaintInRect(test_view->bounds());
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
 
   // Move v1 to a new origin out of the way of our next query.
   v1->SetBoundsRect(gfx::Rect(50, 60, 100, 101));
   // The move will force a repaint.
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
 
   // Schedule a paint with damage rect where v1 used to be.
   test_view->SchedulePaintInRect(gfx::Rect(5, 6, 10, 11));
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
 
   // Should only have picked up root_view and test_view.
   EXPECT_EQ(2U, test_view->last_cull_set_.size());
@@ -3480,8 +3467,7 @@ TEST_F(ViewLayerTest, BoundsTreeLayerChangeMakesNewTree) {
   // Schedule a full-view paint to get everyone's rectangles updated.
   test_view->SchedulePaintInRect(test_view->bounds());
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
 
   // Set v1 to paint to its own layer, it should remove itself from the
   // test_view heiarchy and no longer intersect with damage rects in that cull
@@ -3491,8 +3477,7 @@ TEST_F(ViewLayerTest, BoundsTreeLayerChangeMakesNewTree) {
   // Schedule another full-view paint.
   test_view->SchedulePaintInRect(test_view->bounds());
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
   // v1 and v2 should no longer be present in the test_view cull_set.
   EXPECT_EQ(2U, test_view->last_cull_set_.size());
   EXPECT_EQ(0U, test_view->last_cull_set_.count(v1));
@@ -3503,8 +3488,7 @@ TEST_F(ViewLayerTest, BoundsTreeLayerChangeMakesNewTree) {
   // Schedule another full-view paint.
   test_view->SchedulePaintInRect(test_view->bounds());
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
   // We should be back to the full cull set including v1 and v2.
   EXPECT_EQ(4U, test_view->last_cull_set_.size());
   EXPECT_EQ(1U, test_view->last_cull_set_.count(widget()->GetRootView()));
@@ -3528,8 +3512,7 @@ TEST_F(ViewLayerTest, BoundsTreeRemoveChildRemovesBounds) {
   // Schedule a full-view paint to get everyone's rectangles updated.
   test_view->SchedulePaintInRect(test_view->bounds());
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
 
   // Now remove v1 from the root view.
   test_view->RemoveChildView(v1);
@@ -3537,8 +3520,7 @@ TEST_F(ViewLayerTest, BoundsTreeRemoveChildRemovesBounds) {
   // Schedule another full-view paint.
   test_view->SchedulePaintInRect(test_view->bounds());
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
   // v1 and v2 should no longer be present in the test_view cull_set.
   EXPECT_EQ(2U, test_view->last_cull_set_.size());
   EXPECT_EQ(0U, test_view->last_cull_set_.count(v1));
@@ -3569,8 +3551,7 @@ TEST_F(ViewLayerTest, BoundsTreeMoveViewMovesBounds) {
   // Schedule a full-view paint and ensure all views are present in the cull.
   test_view->SchedulePaintInRect(test_view->bounds());
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
   EXPECT_EQ(5U, test_view->last_cull_set_.size());
   EXPECT_EQ(1U, test_view->last_cull_set_.count(widget()->GetRootView()));
   EXPECT_EQ(1U, test_view->last_cull_set_.count(test_view));
@@ -3593,8 +3574,7 @@ TEST_F(ViewLayerTest, BoundsTreeMoveViewMovesBounds) {
   test_view->SchedulePaintInRect(test_view->bounds());
   widget_view->SchedulePaintInRect(widget_view->bounds());
   GetRootLayer()->GetCompositor()->ScheduleDraw();
-  ui::DrawWaiterForTest::WaitForCompositingEnded(
-      GetRootLayer()->GetCompositor());
+  ui::DrawWaiterForTest::Wait(GetRootLayer()->GetCompositor());
 
   // Only v1 should be present in the first cull set.
   EXPECT_EQ(3U, test_view->last_cull_set_.size());