Update from https://crrev.com/304121

cc/scheduler/scheduler_unittest.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
+
 #include "cc/scheduler/scheduler.h"
 
 #include <string>
 #include <vector>
 
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/memory/scoped_vector.h"
 #include "base/message_loop/message_loop.h"
 #include "base/power_monitor/power_monitor.h"
@@ skipping 26 matching lines @@
 namespace cc {
 namespace {
 
 class FakeSchedulerClient;
 
 void InitializeOutputSurfaceAndFirstCommit(Scheduler* scheduler,
                                            FakeSchedulerClient* client);
 
 class FakeSchedulerClient : public SchedulerClient {
  public:
-  struct FakeBeginFrameSourceForFakeSchedulerClient
-      : public FakeBeginFrameSource {
-    FakeSchedulerClient* client_;
-
-    explicit FakeBeginFrameSourceForFakeSchedulerClient(
-        FakeSchedulerClient* client)
+  class FakeExternalBeginFrameSource : public BeginFrameSourceMixIn {
+   public:
+    explicit FakeExternalBeginFrameSource(FakeSchedulerClient* client)
         : client_(client) {}
+    virtual ~FakeExternalBeginFrameSource() {}
 
     void OnNeedsBeginFramesChange(bool needs_begin_frames) override {
       if (needs_begin_frames) {
         client_->actions_.push_back("SetNeedsBeginFrames(true)");
       } else {
         client_->actions_.push_back("SetNeedsBeginFrames(false)");
       }
       client_->states_.push_back(client_->scheduler_->AsValue());
     }
+
+    void TestOnBeginFrame(const BeginFrameArgs& args) {
+      return CallOnBeginFrame(args);
+    }
+
+   private:
+    FakeSchedulerClient* client_;
   };
 
   class FakePowerMonitorSource : public base::PowerMonitorSource {
    public:
     FakePowerMonitorSource() {}
     ~FakePowerMonitorSource() override {}
     void GeneratePowerStateEvent(bool on_battery_power) {
       on_battery_power_impl_ = on_battery_power;
       ProcessPowerEvent(POWER_STATE_EVENT);
       base::MessageLoop::current()->RunUntilIdle();
     }
     bool IsOnBatteryPowerImpl() override { return on_battery_power_impl_; }
 
    private:
     bool on_battery_power_impl_;
   };
 
   FakeSchedulerClient()
       : automatic_swap_ack_(true),
         swap_contains_incomplete_tile_(false),
         redraw_will_happen_if_update_visible_tiles_happens_(false),
         now_src_(TestNowSource::Create()),
         task_runner_(new OrderedSimpleTaskRunner(now_src_, true)),
-        fake_frame_source_(this),
+        fake_external_begin_frame_source_(nullptr),
         fake_power_monitor_source_(new FakePowerMonitorSource),
         power_monitor_(make_scoped_ptr<base::PowerMonitorSource>(
             fake_power_monitor_source_)),
         scheduler_(nullptr) {
     // A bunch of tests require Now() to be > BeginFrameArgs::DefaultInterval()
     now_src_->AdvanceNow(base::TimeDelta::FromMilliseconds(100));
     // Fail if we need to run 100 tasks in a row.
     task_runner_->SetRunTaskLimit(100);
     Reset();
   }
 
   void Reset() {
     actions_.clear();
     states_.clear();
     draw_will_happen_ = true;
     swap_will_happen_if_draw_happens_ = true;
     num_draws_ = 0;
     log_anticipated_draw_time_change_ = false;
   }
 
   TestScheduler* CreateScheduler(const SchedulerSettings& settings) {
-    scheduler_ = TestScheduler::Create(
-        now_src_, this, settings, 0, task_runner_, &power_monitor_);
+    scoped_ptr<FakeExternalBeginFrameSource> fake_external_begin_frame_source;
+    if (settings.use_external_begin_frame_source &&
+        settings.throttle_frame_production) {
+      fake_external_begin_frame_source.reset(
+          new FakeExternalBeginFrameSource(this));
+      fake_external_begin_frame_source_ =
+          fake_external_begin_frame_source.get();
+    }
+    scheduler_ = TestScheduler::Create(now_src_,
+                                       this,
+                                       settings,
+                                       0,
+                                       task_runner_,
+                                       &power_monitor_,
+                                       fake_external_begin_frame_source.Pass());
     DCHECK(scheduler_);
     return scheduler_.get();
   }
 
   // Most tests don't care about DidAnticipatedDrawTimeChange, so only record it
   // for tests that do.
   void set_log_anticipated_draw_time_change(bool log) {
     log_anticipated_draw_time_change_ = log;
   }
-  bool needs_begin_frames() { return fake_frame_source_.NeedsBeginFrames(); }
+  bool needs_begin_frames() {
+    DCHECK(ExternalBeginFrame());
+    return fake_external_begin_frame_source_->NeedsBeginFrames();
+  }
   int num_draws() const { return num_draws_; }
   int num_actions_() const { return static_cast<int>(actions_.size()); }
   const char* Action(int i) const { return actions_[i]; }
   std::string StateForAction(int i) const { return states_[i]->ToString(); }
   base::TimeTicks posted_begin_impl_frame_deadline() const {
     return posted_begin_impl_frame_deadline_;
   }
 
   bool ExternalBeginFrame() {
-    return scheduler_->settings().begin_frame_scheduling_enabled &&
+    return scheduler_->settings().use_external_begin_frame_source &&
            scheduler_->settings().throttle_frame_production;
   }
-  FakeBeginFrameSource* ExternalBeginFrameSource() override {
-    return &fake_frame_source_;
+
+  FakeExternalBeginFrameSource* fake_external_begin_frame_source() const {
+    return fake_external_begin_frame_source_;
   }
 
   base::PowerMonitor* PowerMonitor() { return &power_monitor_; }
 
   FakePowerMonitorSource* PowerMonitorSource() {
     return fake_power_monitor_source_;
   }
 
   void AdvanceFrame() {
     TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("cc.debug.scheduler.frames"),
                  "FakeSchedulerClient::AdvanceFrame");
-    // EXPECT_TRUE(needs_begin_frames());
     if (ExternalBeginFrame()) {
       // Creep the time forward so that any BeginFrameArgs is not equal to the
       // last one otherwise we violate the BeginFrameSource contract.
       now_src_->AdvanceNowMicroseconds(1);
-      fake_frame_source_.TestOnBeginFrame(
+      fake_external_begin_frame_source_->TestOnBeginFrame(
           CreateBeginFrameArgsForTesting(now_src_));
       EXPECT_TRUE(scheduler_->BeginImplFrameDeadlinePending());
     }
 
     EXPECT_TRUE(task_runner().RunTasksWhile(ImplFrameDeadlinePending(false)));
     EXPECT_TRUE(scheduler_->BeginImplFrameDeadlinePending());
   }
 
   OrderedSimpleTaskRunner& task_runner() { return *task_runner_; }
   TestNowSource* now_src() { return now_src_.get(); }
@@ skipping 117 matching lines @@
   bool automatic_swap_ack_;
   int num_draws_;
   bool log_anticipated_draw_time_change_;
   bool swap_contains_incomplete_tile_;
   bool redraw_will_happen_if_update_visible_tiles_happens_;
   base::TimeTicks posted_begin_impl_frame_deadline_;
   std::vector<const char*> actions_;
   std::vector<scoped_refptr<base::debug::ConvertableToTraceFormat>> states_;
   scoped_refptr<TestNowSource> now_src_;
   scoped_refptr<OrderedSimpleTaskRunner> task_runner_;
-  FakeBeginFrameSourceForFakeSchedulerClient fake_frame_source_;
+  FakeExternalBeginFrameSource* fake_external_begin_frame_source_;
   FakePowerMonitorSource* fake_power_monitor_source_;
   base::PowerMonitor power_monitor_;
   scoped_ptr<TestScheduler> scheduler_;
 };
 
 void InitializeOutputSurfaceAndFirstCommit(Scheduler* scheduler,
                                            FakeSchedulerClient* client) {
   TRACE_EVENT0("cc",
                "SchedulerUnitTest::InitializeOutputSurfaceAndFirstCommit");
 
@@ skipping 18 matching lines @@
     SCOPED_TRACE(
         "We need another BeginImplFrame so Scheduler calls "
         "SetNeedsBeginFrame(false).");
     client->AdvanceFrame();
   }
 
   // Run the posted deadline task.
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
   client->task_runner().RunTasksWhile(client->ImplFrameDeadlinePending(true));
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
-
-  // EXPECT_FALSE(client->needs_begin_frames());
 }
 
 TEST(SchedulerTest, InitializeOutputSurfaceDoesNotBeginImplFrame) {
   FakeSchedulerClient client;
-  SchedulerSettings default_scheduler_settings;
-  TestScheduler* scheduler = client.CreateScheduler(default_scheduler_settings);
+  SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
+  TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
 
   EXPECT_SINGLE_ACTION("ScheduledActionBeginOutputSurfaceCreation", client);
   client.Reset();
   scheduler->DidCreateAndInitializeOutputSurface();
   EXPECT_NO_ACTION(client);
 }
 
 TEST(SchedulerTest, RequestCommit) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
 
   EXPECT_SINGLE_ACTION("ScheduledActionBeginOutputSurfaceCreation", client);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   // SetNeedsCommit should begin the frame on the next BeginImplFrame.
   client.Reset();
@@ skipping 45 matching lines @@
   client.Reset();
 
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_SINGLE_ACTION("SetNeedsBeginFrames(false)", client);
   client.Reset();
 }
 
 TEST(SchedulerTest, RequestCommitAfterBeginMainFrameSent) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
 
   EXPECT_SINGLE_ACTION("ScheduledActionBeginOutputSurfaceCreation", client);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
   client.Reset();
 
   // SetNeedsCommit should begin the frame.
@@ skipping 78 matching lines @@
   void ScheduledActionBeginOutputSurfaceCreation() override {}
   void DidAnticipatedDrawTimeChange(base::TimeTicks) override {}
 };
 
 // Tests for two different situations:
 // 1. the scheduler dropping SetNeedsRedraw requests that happen inside
 //    a ScheduledActionDrawAndSwap
 // 2. the scheduler drawing twice inside a single tick
 TEST(SchedulerTest, RequestRedrawInsideDraw) {
   SchedulerClientThatsetNeedsDrawInsideDraw client;
-  SchedulerSettings default_scheduler_settings;
-  TestScheduler* scheduler = client.CreateScheduler(default_scheduler_settings);
+  SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
+  TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
   client.Reset();
 
   scheduler->SetNeedsRedraw();
   EXPECT_TRUE(scheduler->RedrawPending());
   EXPECT_TRUE(client.needs_begin_frames());
   EXPECT_EQ(0, client.num_draws());
@@ skipping 15 matching lines @@
   client.AdvanceFrame();
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_EQ(2, client.num_draws());
   EXPECT_FALSE(scheduler->RedrawPending());
   EXPECT_FALSE(client.needs_begin_frames());
 }
 
 // Test that requesting redraw inside a failed draw doesn't lose the request.
 TEST(SchedulerTest, RequestRedrawInsideFailedDraw) {
   SchedulerClientThatsetNeedsDrawInsideDraw client;
-  SchedulerSettings default_scheduler_settings;
-  TestScheduler* scheduler = client.CreateScheduler(default_scheduler_settings);
+  SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
+  TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
   client.Reset();
 
   client.SetDrawWillHappen(false);
 
   scheduler->SetNeedsRedraw();
   EXPECT_TRUE(scheduler->RedrawPending());
@@ skipping 56 matching lines @@
   void SetNeedsCommitOnNextDraw() { set_needs_commit_on_next_draw_ = true; }
 
  private:
   bool set_needs_commit_on_next_draw_;
 };
 
 // Tests for the scheduler infinite-looping on SetNeedsCommit requests that
 // happen inside a ScheduledActionDrawAndSwap
 TEST(SchedulerTest, RequestCommitInsideDraw) {
   SchedulerClientThatSetNeedsCommitInsideDraw client;
-  SchedulerSettings default_scheduler_settings;
-  TestScheduler* scheduler = client.CreateScheduler(default_scheduler_settings);
+  SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
+  TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
   client.Reset();
 
   EXPECT_FALSE(client.needs_begin_frames());
   scheduler->SetNeedsRedraw();
   EXPECT_TRUE(scheduler->RedrawPending());
   EXPECT_EQ(0, client.num_draws());
@@ skipping 23 matching lines @@
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_EQ(2, client.num_draws());
   EXPECT_FALSE(scheduler->RedrawPending());
   EXPECT_FALSE(scheduler->CommitPending());
   EXPECT_FALSE(client.needs_begin_frames());
 }
 
 // Tests that when a draw fails then the pending commit should not be dropped.
 TEST(SchedulerTest, RequestCommitInsideFailedDraw) {
   SchedulerClientThatsetNeedsDrawInsideDraw client;
-  SchedulerSettings default_scheduler_settings;
-  TestScheduler* scheduler = client.CreateScheduler(default_scheduler_settings);
+  SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
+  TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
   client.Reset();
 
   client.SetDrawWillHappen(false);
 
   scheduler->SetNeedsRedraw();
   EXPECT_TRUE(scheduler->RedrawPending());
@@ skipping 25 matching lines @@
   client.AdvanceFrame();
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_EQ(3, client.num_draws());
   EXPECT_TRUE(scheduler->CommitPending());
   EXPECT_FALSE(scheduler->RedrawPending());
   EXPECT_TRUE(client.needs_begin_frames());
 }
 
 TEST(SchedulerTest, NoSwapWhenDrawFails) {
   SchedulerClientThatSetNeedsCommitInsideDraw client;
-  SchedulerSettings default_scheduler_settings;
-  TestScheduler* scheduler = client.CreateScheduler(default_scheduler_settings);
+  SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
+  TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
   client.Reset();
 
   scheduler->SetNeedsRedraw();
   EXPECT_TRUE(scheduler->RedrawPending());
   EXPECT_TRUE(client.needs_begin_frames());
   EXPECT_EQ(0, client.num_draws());
@@ skipping 20 matching lines @@
  public:
   DrawResult ScheduledActionDrawAndSwapIfPossible() override {
     scheduler_->SetNeedsManageTiles();
     return FakeSchedulerClient::ScheduledActionDrawAndSwapIfPossible();
   }
 };
 
 // Test manage tiles is independant of draws.
 TEST(SchedulerTest, ManageTiles) {
   SchedulerClientNeedsManageTilesInDraw client;
-  SchedulerSettings default_scheduler_settings;
-  TestScheduler* scheduler = client.CreateScheduler(default_scheduler_settings);
+  SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
+  TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   // Request both draw and manage tiles. ManageTiles shouldn't
   // be trigged until BeginImplFrame.
   client.Reset();
   scheduler->SetNeedsManageTiles();
   scheduler->SetNeedsRedraw();
@@ skipping 84 matching lines @@
   EXPECT_EQ(0, client.num_draws());
   EXPECT_FALSE(client.HasAction("ScheduledActionDrawAndSwapIfPossible"));
   EXPECT_TRUE(client.HasAction("ScheduledActionManageTiles"));
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
 }
 
 // Test that ManageTiles only happens once per frame.  If an external caller
 // initiates it, then the state machine should not ManageTiles on that frame.
 TEST(SchedulerTest, ManageTilesOncePerFrame) {
   FakeSchedulerClient client;
-  SchedulerSettings default_scheduler_settings;
-  TestScheduler* scheduler = client.CreateScheduler(default_scheduler_settings);
+  SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
+  TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   // If DidManageTiles during a frame, then ManageTiles should not occur again.
   scheduler->SetNeedsManageTiles();
   scheduler->SetNeedsRedraw();
   client.Reset();
   client.AdvanceFrame();
@@ skipping 98 matching lines @@
   EXPECT_FALSE(scheduler->RedrawPending());
   EXPECT_FALSE(scheduler->ManageTilesPending());
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
   scheduler->DidManageTiles();  // Corresponds to ScheduledActionManageTiles
 }
 
 TEST(SchedulerTest, ShouldUpdateVisibleTiles) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
   scheduler_settings.impl_side_painting = true;
+  scheduler_settings.use_external_begin_frame_source = true;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   client.SetRedrawWillHappenIfUpdateVisibleTilesHappens(true);
 
   // SetNeedsCommit should begin the frame.
   client.Reset();
@@ skipping 39 matching lines @@
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
 
   // No more UpdateVisibleTiles().
   client.Reset();
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_SINGLE_ACTION("SetNeedsBeginFrames(false)", client);
 }
 
 TEST(SchedulerTest, TriggerBeginFrameDeadlineEarly) {
   SchedulerClientNeedsManageTilesInDraw client;
-  SchedulerSettings default_scheduler_settings;
-  TestScheduler* scheduler = client.CreateScheduler(default_scheduler_settings);
+  SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
+  TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   client.Reset();
   scheduler->SetNeedsRedraw();
   client.AdvanceFrame();
 
   // The deadline should be zero since there is no work other than drawing
@@ skipping 29 matching lines @@
 void MainFrameInHighLatencyMode(int64 begin_main_frame_to_commit_estimate_in_ms,
                                 int64 commit_to_activate_estimate_in_ms,
                                 bool impl_latency_takes_priority,
                                 bool should_send_begin_main_frame) {
   // Set up client with specified estimates (draw duration is set to 1).
   SchedulerClientWithFixedEstimates client(
       base::TimeDelta::FromMilliseconds(1),
       base::TimeDelta::FromMilliseconds(
           begin_main_frame_to_commit_estimate_in_ms),
       base::TimeDelta::FromMilliseconds(commit_to_activate_estimate_in_ms));
-  SchedulerSettings default_scheduler_settings;
-  TestScheduler* scheduler = client.CreateScheduler(default_scheduler_settings);
+  SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
+  TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   scheduler->SetImplLatencyTakesPriority(impl_latency_takes_priority);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   // Impl thread hits deadline before commit finishes.
   client.Reset();
   scheduler->SetNeedsCommit();
   EXPECT_FALSE(scheduler->MainThreadIsInHighLatencyMode());
@@ skipping 45 matching lines @@
 }
 
 TEST(SchedulerTest, PollForCommitCompletion) {
   // Since we are simulating a long commit, set up a client with draw duration
   // estimates that prevent skipping main frames to get to low latency mode.
   SchedulerClientWithFixedEstimates client(
       base::TimeDelta::FromMilliseconds(1),
       base::TimeDelta::FromMilliseconds(32),
       base::TimeDelta::FromMilliseconds(32));
   client.set_log_anticipated_draw_time_change(true);
-  SchedulerSettings default_scheduler_settings;
-  TestScheduler* scheduler = client.CreateScheduler(default_scheduler_settings);
+  SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
+  TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
 
   scheduler->SetCanDraw(true);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->DidCreateAndInitializeOutputSurface();
 
   scheduler->SetNeedsCommit();
   EXPECT_TRUE(scheduler->CommitPending());
   scheduler->NotifyBeginMainFrameStarted();
   scheduler->NotifyReadyToCommit();
   scheduler->SetNeedsRedraw();
 
   BeginFrameArgs frame_args = CreateBeginFrameArgsForTesting(client.now_src());
   frame_args.interval = base::TimeDelta::FromMilliseconds(1000);
-  client.ExternalBeginFrameSource()->TestOnBeginFrame(frame_args);
+  client.fake_external_begin_frame_source()->TestOnBeginFrame(frame_args);
 
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
 
   scheduler->DidSwapBuffers();
   scheduler->DidSwapBuffersComplete();
 
   // At this point, we've drawn a frame. Start another commit, but hold off on
   // the NotifyReadyToCommit for now.
   EXPECT_FALSE(scheduler->CommitPending());
   scheduler->SetNeedsCommit();
-  client.ExternalBeginFrameSource()->TestOnBeginFrame(frame_args);
+  client.fake_external_begin_frame_source()->TestOnBeginFrame(frame_args);
   EXPECT_TRUE(scheduler->CommitPending());
 
   // Draw and swap the frame, but don't ack the swap to simulate the Browser
   // blocking on the renderer.
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
   scheduler->DidSwapBuffers();
 
   // Spin the event loop a few times and make sure we get more
@@ skipping 22 matching lines @@
     EXPECT_GT(client.num_actions_(), actions_so_far);
     EXPECT_STREQ(client.Action(client.num_actions_() - 1),
                  "DidAnticipatedDrawTimeChange");
     actions_so_far = client.num_actions_();
   }
 }
 
 TEST(SchedulerTest, BeginRetroFrame) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   // SetNeedsCommit should begin the frame on the next BeginImplFrame.
   client.Reset();
   scheduler->SetNeedsCommit();
   EXPECT_SINGLE_ACTION("SetNeedsBeginFrames(true)", client);
   client.Reset();
 
   // Create a BeginFrame with a long deadline to avoid race conditions.
   // This is the first BeginFrame, which will be handled immediately.
   BeginFrameArgs args = CreateBeginFrameArgsForTesting(client.now_src());
   args.deadline += base::TimeDelta::FromHours(1);
-  client.ExternalBeginFrameSource()->TestOnBeginFrame(args);
+  client.fake_external_begin_frame_source()->TestOnBeginFrame(args);
   EXPECT_ACTION("WillBeginImplFrame", client, 0, 2);
   EXPECT_ACTION("ScheduledActionSendBeginMainFrame", client, 1, 2);
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
   EXPECT_TRUE(client.needs_begin_frames());
   client.Reset();
 
   // Queue BeginFrames while we are still handling the previous BeginFrame.
   args.frame_time += base::TimeDelta::FromSeconds(1);
-  client.ExternalBeginFrameSource()->TestOnBeginFrame(args);
+  client.fake_external_begin_frame_source()->TestOnBeginFrame(args);
   args.frame_time += base::TimeDelta::FromSeconds(1);
-  client.ExternalBeginFrameSource()->TestOnBeginFrame(args);
+  client.fake_external_begin_frame_source()->TestOnBeginFrame(args);
 
   // If we don't swap on the deadline, we wait for the next BeginImplFrame.
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_NO_ACTION(client);
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
   EXPECT_TRUE(client.needs_begin_frames());
   client.Reset();
 
   // NotifyReadyToCommit should trigger the commit.
   scheduler->NotifyBeginMainFrameStarted();
@@ skipping 25 matching lines @@
   client.Reset();
 
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_SINGLE_ACTION("SetNeedsBeginFrames(false)", client);
   client.Reset();
 }
 
 TEST(SchedulerTest, BeginRetroFrame_SwapThrottled) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   // To test swap ack throttling, this test disables automatic swap acks.
   scheduler->SetMaxSwapsPending(1);
   client.SetAutomaticSwapAck(false);
 
   // SetNeedsCommit should begin the frame on the next BeginImplFrame.
   client.Reset();
   scheduler->SetNeedsCommit();
   EXPECT_SINGLE_ACTION("SetNeedsBeginFrames(true)", client);
   client.Reset();
 
   // Create a BeginFrame with a long deadline to avoid race conditions.
   // This is the first BeginFrame, which will be handled immediately.
   BeginFrameArgs args = CreateBeginFrameArgsForTesting(client.now_src());
   args.deadline += base::TimeDelta::FromHours(1);
-  client.ExternalBeginFrameSource()->TestOnBeginFrame(args);
+  client.fake_external_begin_frame_source()->TestOnBeginFrame(args);
   EXPECT_ACTION("WillBeginImplFrame", client, 0, 2);
   EXPECT_ACTION("ScheduledActionSendBeginMainFrame", client, 1, 2);
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
   EXPECT_TRUE(client.needs_begin_frames());
   client.Reset();
 
   // Queue BeginFrame while we are still handling the previous BeginFrame.
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
   args.frame_time += base::TimeDelta::FromSeconds(1);
-  client.ExternalBeginFrameSource()->TestOnBeginFrame(args);
+  client.fake_external_begin_frame_source()->TestOnBeginFrame(args);
   EXPECT_NO_ACTION(client);
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
   client.Reset();
 
   // NotifyReadyToCommit should trigger the pending commit and draw.
   scheduler->NotifyBeginMainFrameStarted();
   scheduler->NotifyReadyToCommit();
   EXPECT_SINGLE_ACTION("ScheduledActionCommit", client);
   EXPECT_TRUE(client.needs_begin_frames());
   client.Reset();
@@ skipping 10 matching lines @@
   // but not a BeginMainFrame or draw.
   scheduler->SetNeedsCommit();
   client.task_runner().RunPendingTasks();  // Run posted BeginRetroFrame.
   EXPECT_ACTION("WillBeginImplFrame", client, 0, 1);
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
   EXPECT_TRUE(client.needs_begin_frames());
   client.Reset();
 
   // Queue BeginFrame while we are still handling the previous BeginFrame.
   args.frame_time += base::TimeDelta::FromSeconds(1);
-  client.ExternalBeginFrameSource()->TestOnBeginFrame(args);
+  client.fake_external_begin_frame_source()->TestOnBeginFrame(args);
   EXPECT_NO_ACTION(client);
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
   EXPECT_TRUE(client.needs_begin_frames());
   client.Reset();
 
   // Take us out of a swap throttled state.
   scheduler->DidSwapBuffersComplete();
   EXPECT_ACTION("ScheduledActionSendBeginMainFrame", client, 0, 1);
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
   EXPECT_TRUE(client.needs_begin_frames());
   client.Reset();
 
   // BeginImplFrame deadline should draw.
   scheduler->SetNeedsRedraw();
 
   EXPECT_TRUE(client.task_runner().RunTasksWhile(
       client.ImplFrameDeadlinePending(true)));
 
   EXPECT_ACTION("ScheduledActionAnimate", client, 0, 2);
   EXPECT_ACTION("ScheduledActionDrawAndSwapIfPossible", client, 1, 2);
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
   EXPECT_TRUE(client.needs_begin_frames());
   client.Reset();
 }
 
-void BeginFramesNotFromClient(bool begin_frame_scheduling_enabled,
+void BeginFramesNotFromClient(bool use_external_begin_frame_source,
                               bool throttle_frame_production) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
-  scheduler_settings.begin_frame_scheduling_enabled =
-      begin_frame_scheduling_enabled;
+  scheduler_settings.use_external_begin_frame_source =
+      use_external_begin_frame_source;
   scheduler_settings.throttle_frame_production = throttle_frame_production;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
+  DCHECK(!client.fake_external_begin_frame_source());
+
   // SetNeedsCommit should begin the frame on the next BeginImplFrame
   // without calling SetNeedsBeginFrame.
   client.Reset();
   scheduler->SetNeedsCommit();
-  EXPECT_FALSE(client.needs_begin_frames());
   EXPECT_NO_ACTION(client);
   client.Reset();
 
   // When the client-driven BeginFrame are disabled, the scheduler posts it's
   // own BeginFrame tasks.
   client.task_runner().RunPendingTasks();  // Run posted BeginFrame.
   EXPECT_ACTION("WillBeginImplFrame", client, 0, 2);
   EXPECT_ACTION("ScheduledActionSendBeginMainFrame", client, 1, 2);
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
-  EXPECT_FALSE(client.needs_begin_frames());
   client.Reset();
 
   // If we don't swap on the deadline, we wait for the next BeginFrame.
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_NO_ACTION(client);
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
-  EXPECT_FALSE(client.needs_begin_frames());
   client.Reset();
 
   // NotifyReadyToCommit should trigger the commit.
   scheduler->NotifyBeginMainFrameStarted();
   scheduler->NotifyReadyToCommit();
   EXPECT_SINGLE_ACTION("ScheduledActionCommit", client);
-  EXPECT_FALSE(client.needs_begin_frames());
   client.Reset();
 
   // BeginImplFrame should prepare the draw.
   client.task_runner().RunPendingTasks();  // Run posted BeginFrame.
   EXPECT_ACTION("WillBeginImplFrame", client, 0, 2);
   EXPECT_ACTION("ScheduledActionAnimate", client, 1, 2);
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
-  EXPECT_FALSE(client.needs_begin_frames());
   client.Reset();
 
   // BeginImplFrame deadline should draw.
   client.task_runner().RunTasksWhile(client.ImplFrameDeadlinePending(true));
   EXPECT_ACTION("ScheduledActionDrawAndSwapIfPossible", client, 0, 1);
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
-  EXPECT_FALSE(client.needs_begin_frames());
   client.Reset();
 
   // The following BeginImplFrame deadline should SetNeedsBeginFrame(false)
   // to avoid excessive toggles.
   client.task_runner().RunPendingTasks();  // Run posted BeginFrame.
   EXPECT_SINGLE_ACTION("WillBeginImplFrame", client);
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
   client.Reset();
 
   // Make sure SetNeedsBeginFrame isn't called on the client
   // when the BeginFrame is no longer needed.
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_NO_ACTION(client);
-  EXPECT_FALSE(client.needs_begin_frames());
   client.Reset();
 }
 
 TEST(SchedulerTest, SyntheticBeginFrames) {
-  bool begin_frame_scheduling_enabled = false;
+  bool use_external_begin_frame_source = false;
   bool throttle_frame_production = true;
-  BeginFramesNotFromClient(begin_frame_scheduling_enabled,
+  BeginFramesNotFromClient(use_external_begin_frame_source,
                            throttle_frame_production);
 }
 
 TEST(SchedulerTest, VSyncThrottlingDisabled) {
-  bool begin_frame_scheduling_enabled = true;
+  bool use_external_begin_frame_source = true;
   bool throttle_frame_production = false;
-  BeginFramesNotFromClient(begin_frame_scheduling_enabled,
+  BeginFramesNotFromClient(use_external_begin_frame_source,
                            throttle_frame_production);
 }
 
 TEST(SchedulerTest, SyntheticBeginFrames_And_VSyncThrottlingDisabled) {
-  bool begin_frame_scheduling_enabled = false;
+  bool use_external_begin_frame_source = false;
   bool throttle_frame_production = false;
-  BeginFramesNotFromClient(begin_frame_scheduling_enabled,
+  BeginFramesNotFromClient(use_external_begin_frame_source,
                            throttle_frame_production);
 }
 
-void BeginFramesNotFromClient_SwapThrottled(bool begin_frame_scheduling_enabled,
-                                            bool throttle_frame_production) {
+void BeginFramesNotFromClient_SwapThrottled(
+    bool use_external_begin_frame_source,
+    bool throttle_frame_production) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
-  scheduler_settings.begin_frame_scheduling_enabled =
-      begin_frame_scheduling_enabled;
+  scheduler_settings.use_external_begin_frame_source =
+      use_external_begin_frame_source;
   scheduler_settings.throttle_frame_production = throttle_frame_production;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
+  DCHECK(!client.fake_external_begin_frame_source());
+
   // To test swap ack throttling, this test disables automatic swap acks.
   scheduler->SetMaxSwapsPending(1);
   client.SetAutomaticSwapAck(false);
 
   // SetNeedsCommit should begin the frame on the next BeginImplFrame.
   client.Reset();
   scheduler->SetNeedsCommit();
-  EXPECT_FALSE(client.needs_begin_frames());
   EXPECT_NO_ACTION(client);
   client.Reset();
 
   // Trigger the first BeginImplFrame and BeginMainFrame
   client.task_runner().RunPendingTasks();  // Run posted BeginFrame.
   EXPECT_ACTION("WillBeginImplFrame", client, 0, 2);
   EXPECT_ACTION("ScheduledActionSendBeginMainFrame", client, 1, 2);
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
-  EXPECT_FALSE(client.needs_begin_frames());
   client.Reset();
 
   // NotifyReadyToCommit should trigger the pending commit and draw.
   scheduler->NotifyBeginMainFrameStarted();
   scheduler->NotifyReadyToCommit();
   EXPECT_SINGLE_ACTION("ScheduledActionCommit", client);
-  EXPECT_FALSE(client.needs_begin_frames());
   client.Reset();
 
   // Swapping will put us into a swap throttled state.
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_ACTION("ScheduledActionAnimate", client, 0, 2);
   EXPECT_ACTION("ScheduledActionDrawAndSwapIfPossible", client, 1, 2);
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
-  EXPECT_FALSE(client.needs_begin_frames());
   client.Reset();
 
   // While swap throttled, BeginFrames should trigger BeginImplFrames,
   // but not a BeginMainFrame or draw.
   scheduler->SetNeedsCommit();
   client.task_runner().RunPendingTasks();  // Run posted BeginFrame.
   EXPECT_ACTION("WillBeginImplFrame", client, 0, 1);
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
-  EXPECT_FALSE(client.needs_begin_frames());
   client.Reset();
 
   // Take us out of a swap throttled state.
   scheduler->DidSwapBuffersComplete();
   EXPECT_ACTION("ScheduledActionSendBeginMainFrame", client, 0, 1);
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
-  EXPECT_FALSE(client.needs_begin_frames());
   client.Reset();
 
   // BeginImplFrame deadline should draw.
   scheduler->SetNeedsRedraw();
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_ACTION("ScheduledActionAnimate", client, 0, 2);
   EXPECT_ACTION("ScheduledActionDrawAndSwapIfPossible", client, 1, 2);
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
-  EXPECT_FALSE(client.needs_begin_frames());
   client.Reset();
 }
 
 TEST(SchedulerTest, SyntheticBeginFrames_SwapThrottled) {
-  bool begin_frame_scheduling_enabled = false;
+  bool use_external_begin_frame_source = false;
   bool throttle_frame_production = true;
-  BeginFramesNotFromClient_SwapThrottled(begin_frame_scheduling_enabled,
+  BeginFramesNotFromClient_SwapThrottled(use_external_begin_frame_source,
                                          throttle_frame_production);
 }
 
 TEST(SchedulerTest, VSyncThrottlingDisabled_SwapThrottled) {
-  bool begin_frame_scheduling_enabled = true;
+  bool use_external_begin_frame_source = true;
   bool throttle_frame_production = false;
-  BeginFramesNotFromClient_SwapThrottled(begin_frame_scheduling_enabled,
+  BeginFramesNotFromClient_SwapThrottled(use_external_begin_frame_source,
                                          throttle_frame_production);
 }
 
 TEST(SchedulerTest,
      SyntheticBeginFrames_And_VSyncThrottlingDisabled_SwapThrottled) {
-  bool begin_frame_scheduling_enabled = false;
+  bool use_external_begin_frame_source = false;
   bool throttle_frame_production = false;
-  BeginFramesNotFromClient_SwapThrottled(begin_frame_scheduling_enabled,
+  BeginFramesNotFromClient_SwapThrottled(use_external_begin_frame_source,
                                          throttle_frame_production);
 }
 
 TEST(SchedulerTest, DidLoseOutputSurfaceAfterOutputSurfaceIsInitialized) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
 
   EXPECT_SINGLE_ACTION("ScheduledActionBeginOutputSurfaceCreation", client);
   client.Reset();
   scheduler->DidCreateAndInitializeOutputSurface();
   EXPECT_NO_ACTION(client);
 
   scheduler->DidLoseOutputSurface();
   EXPECT_SINGLE_ACTION("ScheduledActionBeginOutputSurfaceCreation", client);
 }
 
 TEST(SchedulerTest, DidLoseOutputSurfaceAfterBeginFrameStarted) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
 
   EXPECT_SINGLE_ACTION("ScheduledActionBeginOutputSurfaceCreation", client);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
   // SetNeedsCommit should begin the frame.
   client.Reset();
   scheduler->SetNeedsCommit();
@@ skipping 18 matching lines @@
   client.Reset();
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_SINGLE_ACTION("ScheduledActionBeginOutputSurfaceCreation", client);
 }
 
 void DidLoseOutputSurfaceAfterBeginFrameStartedWithHighLatency(
     bool impl_side_painting) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
   scheduler_settings.impl_side_painting = impl_side_painting;
+  scheduler_settings.use_external_begin_frame_source = true;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
 
   EXPECT_SINGLE_ACTION("ScheduledActionBeginOutputSurfaceCreation", client);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   // SetNeedsCommit should begin the frame.
   client.Reset();
@@ skipping 47 matching lines @@
 TEST(SchedulerTest,
      DidLoseOutputSurfaceAfterBeginFrameStartedWithHighLatencyWithImplPaint) {
   bool impl_side_painting = true;
   DidLoseOutputSurfaceAfterBeginFrameStartedWithHighLatency(impl_side_painting);
 }
 
 void DidLoseOutputSurfaceAfterReadyToCommit(bool impl_side_painting) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
   scheduler_settings.impl_side_painting = impl_side_painting;
+  scheduler_settings.use_external_begin_frame_source = true;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
 
   EXPECT_SINGLE_ACTION("ScheduledActionBeginOutputSurfaceCreation", client);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   // SetNeedsCommit should begin the frame.
   client.Reset();
@@ skipping 30 matching lines @@
   DidLoseOutputSurfaceAfterReadyToCommit(false);
 }
 
 TEST(SchedulerTest, DidLoseOutputSurfaceAfterReadyToCommitWithImplPainting) {
   DidLoseOutputSurfaceAfterReadyToCommit(true);
 }
 
 TEST(SchedulerTest, DidLoseOutputSurfaceAfterSetNeedsManageTiles) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   client.Reset();
   scheduler->SetNeedsManageTiles();
   scheduler->SetNeedsRedraw();
   EXPECT_SINGLE_ACTION("SetNeedsBeginFrames(true)", client);
@@ skipping 10 matching lines @@
 
   client.Reset();
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_ACTION("ScheduledActionManageTiles", client, 0, 2);
   EXPECT_ACTION("ScheduledActionBeginOutputSurfaceCreation", client, 1, 2);
 }
 
 TEST(SchedulerTest, DidLoseOutputSurfaceAfterBeginRetroFramePosted) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   // SetNeedsCommit should begin the frame on the next BeginImplFrame.
   client.Reset();
   scheduler->SetNeedsCommit();
   EXPECT_SINGLE_ACTION("SetNeedsBeginFrames(true)", client);
 
   // Create a BeginFrame with a long deadline to avoid race conditions.
   // This is the first BeginFrame, which will be handled immediately.
   client.Reset();
   BeginFrameArgs args = CreateBeginFrameArgsForTesting(client.now_src());
   args.deadline += base::TimeDelta::FromHours(1);
-  client.ExternalBeginFrameSource()->TestOnBeginFrame(args);
+  client.fake_external_begin_frame_source()->TestOnBeginFrame(args);
   EXPECT_ACTION("WillBeginImplFrame", client, 0, 2);
   EXPECT_ACTION("ScheduledActionSendBeginMainFrame", client, 1, 2);
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
   EXPECT_TRUE(client.needs_begin_frames());
 
   // Queue BeginFrames while we are still handling the previous BeginFrame.
   args.frame_time += base::TimeDelta::FromSeconds(1);
-  client.ExternalBeginFrameSource()->TestOnBeginFrame(args);
+  client.fake_external_begin_frame_source()->TestOnBeginFrame(args);
   args.frame_time += base::TimeDelta::FromSeconds(1);
-  client.ExternalBeginFrameSource()->TestOnBeginFrame(args);
+  client.fake_external_begin_frame_source()->TestOnBeginFrame(args);
 
   // If we don't swap on the deadline, we wait for the next BeginImplFrame.
   client.Reset();
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_NO_ACTION(client);
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
   EXPECT_TRUE(client.needs_begin_frames());
 
   // NotifyReadyToCommit should trigger the commit.
   client.Reset();
@@ skipping 11 matching lines @@
 
   // Posted BeginRetroFrame is aborted.
   client.Reset();
   client.task_runner().RunPendingTasks();
   EXPECT_NO_ACTION(client);
 }
 
 TEST(SchedulerTest, DidLoseOutputSurfaceDuringBeginRetroFrameRunning) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
+  scheduler_settings.use_external_begin_frame_source = true;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   // SetNeedsCommit should begin the frame on the next BeginImplFrame.
   client.Reset();
   scheduler->SetNeedsCommit();
   EXPECT_SINGLE_ACTION("SetNeedsBeginFrames(true)", client);
 
   // Create a BeginFrame with a long deadline to avoid race conditions.
   // This is the first BeginFrame, which will be handled immediately.
   client.Reset();
   BeginFrameArgs args = CreateBeginFrameArgsForTesting(client.now_src());
   args.deadline += base::TimeDelta::FromHours(1);
-  client.ExternalBeginFrameSource()->TestOnBeginFrame(args);
+  client.fake_external_begin_frame_source()->TestOnBeginFrame(args);
   EXPECT_ACTION("WillBeginImplFrame", client, 0, 2);
   EXPECT_ACTION("ScheduledActionSendBeginMainFrame", client, 1, 2);
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
   EXPECT_TRUE(client.needs_begin_frames());
 
   // Queue BeginFrames while we are still handling the previous BeginFrame.
   args.frame_time += base::TimeDelta::FromSeconds(1);
-  client.ExternalBeginFrameSource()->TestOnBeginFrame(args);
+  client.fake_external_begin_frame_source()->TestOnBeginFrame(args);
   args.frame_time += base::TimeDelta::FromSeconds(1);
-  client.ExternalBeginFrameSource()->TestOnBeginFrame(args);
+  client.fake_external_begin_frame_source()->TestOnBeginFrame(args);
 
   // If we don't swap on the deadline, we wait for the next BeginImplFrame.
   client.Reset();
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_NO_ACTION(client);
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
   EXPECT_TRUE(client.needs_begin_frames());
 
   // NotifyReadyToCommit should trigger the commit.
   client.Reset();
@@ skipping 26 matching lines @@
   // No more BeginRetroFrame because BeginRetroFrame queue is cleared.
   client.Reset();
   client.task_runner().RunPendingTasks();
   EXPECT_NO_ACTION(client);
 }
 
 TEST(SchedulerTest,
      StopBeginFrameAfterDidLoseOutputSurfaceWithSyntheticBeginFrameSource) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
-  scheduler_settings.begin_frame_scheduling_enabled = false;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   // SetNeedsCommit should begin the frame on the next BeginImplFrame.
   client.Reset();
   EXPECT_FALSE(scheduler->frame_source().NeedsBeginFrames());
   scheduler->SetNeedsCommit();
@@ skipping 21 matching lines @@
   client.Reset();
   client.task_runner().RunPendingTasks();  // Run posted deadline.
   EXPECT_SINGLE_ACTION("ScheduledActionBeginOutputSurfaceCreation", client);
   EXPECT_FALSE(scheduler->frame_source().NeedsBeginFrames());
 }
 
 TEST(SchedulerTest, ScheduledActionActivateAfterBecomingInvisible) {
   FakeSchedulerClient client;
   SchedulerSettings scheduler_settings;
   scheduler_settings.impl_side_painting = true;
+  scheduler_settings.use_external_begin_frame_source = true;
   TestScheduler* scheduler = client.CreateScheduler(scheduler_settings);
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
 
   EXPECT_SINGLE_ACTION("ScheduledActionBeginOutputSurfaceCreation", client);
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   // SetNeedsCommit should begin the frame.
   client.Reset();
@@ skipping 80 matching lines @@
   before_deadline = client.now_src()->Now();
   EXPECT_TRUE(client.task_runner().RunTasksWhile(
       client.ImplFrameDeadlinePending(true)));
   after_deadline = client.now_src()->Now();
 }
 
 TEST(SchedulerTest,
      SimulateWindowsLowResolutionTimerOnBattery_PrioritizeImplLatencyOff) {
   FakeSchedulerClient client;
   SchedulerSettings settings;
+  settings.use_external_begin_frame_source = true;
   TestScheduler* scheduler = client.CreateScheduler(settings);
 
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
 
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   // Set needs commit so that the scheduler tries to wait for the main thread
   scheduler->SetNeedsCommit();
@@ skipping 25 matching lines @@
   client.task_runner().RunPendingTasks();
   // Deadline task finally completes
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
 }
 
 TEST(SchedulerTest,
      SimulateWindowsLowResolutionTimerOnBattery_PrioritizeImplLatencyOn) {
   FakeSchedulerClient client;
   SchedulerSettings settings;
   settings.disable_hi_res_timer_tasks_on_battery = true;
+  settings.use_external_begin_frame_source = true;
   TestScheduler* scheduler = client.CreateScheduler(settings);
 
   scheduler->SetCanStart();
   scheduler->SetVisible(true);
   scheduler->SetCanDraw(true);
 
   InitializeOutputSurfaceAndFirstCommit(scheduler, &client);
 
   // Set needs commit so that the scheduler tries to wait for the main thread
   scheduler->SetNeedsCommit();
@@ skipping 15 matching lines @@
 
   // Deadline task is pending
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
   client.task_runner().RunPendingTasks();
   // Deadline task runs immediately
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
 }
 
 }  // namespace
 }  // namespace cc