Update from https://crrev.com/306655

cc/scheduler/scheduler_state_machine_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_state_machine.h"
 
 #include "base/debug/trace_event.h"
 #include "cc/scheduler/scheduler.h"
 #include "cc/test/begin_frame_args_test.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 26 matching lines @@
     {SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE,
      SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING,
      SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME,
      SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE, };
 
 const SchedulerStateMachine::CommitState all_commit_states[] = {
     SchedulerStateMachine::COMMIT_STATE_IDLE,
     SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
     SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_STARTED,
     SchedulerStateMachine::COMMIT_STATE_READY_TO_COMMIT,
-    SchedulerStateMachine::COMMIT_STATE_WAITING_FOR_ACTIVATION};
+    SchedulerStateMachine::COMMIT_STATE_WAITING_FOR_ACTIVATION,
+    SchedulerStateMachine::COMMIT_STATE_WAITING_FOR_DRAW};
 
 // Exposes the protected state fields of the SchedulerStateMachine for testing
 class StateMachine : public SchedulerStateMachine {
  public:
   explicit StateMachine(const SchedulerSettings& scheduler_settings)
       : SchedulerStateMachine(scheduler_settings) {}
 
   void CreateAndInitializeOutputSurfaceWithActivatedCommit() {
     DidCreateAndInitializeOutputSurface();
     output_surface_state_ = OUTPUT_SURFACE_ACTIVE;
@@ skipping 57 matching lines @@
         SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION)
     state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
     state.SetCommitState(SchedulerStateMachine::COMMIT_STATE_IDLE);
     state.SetNeedsRedraw(false);
     state.SetVisible(true);
 
     EXPECT_FALSE(state.BeginFrameNeeded());
 
     EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
     EXPECT_FALSE(state.BeginFrameNeeded());
-    state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+    state.OnBeginImplFrame(
+        CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
 
     EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
     state.OnBeginImplFrameDeadline();
   }
 
   // If commit requested but can_start is still false, do nothing.
   {
     StateMachine state(default_scheduler_settings);
     state.SetCommitState(SchedulerStateMachine::COMMIT_STATE_IDLE);
     state.SetNeedsRedraw(false);
     state.SetVisible(true);
     state.SetNeedsCommit();
 
     EXPECT_FALSE(state.BeginFrameNeeded());
 
     EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
     EXPECT_FALSE(state.BeginFrameNeeded());
-    state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+    state.OnBeginImplFrame(
+        CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
     EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
     state.OnBeginImplFrameDeadline();
   }
 
   // If commit requested, begin a main frame.
   {
     StateMachine state(default_scheduler_settings);
     state.SetCommitState(SchedulerStateMachine::COMMIT_STATE_IDLE);
     state.SetCanStart();
     state.UpdateState(state.NextAction());
     state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
     state.SetNeedsRedraw(false);
     state.SetVisible(true);
     state.SetNeedsCommit();
 
     EXPECT_TRUE(state.BeginFrameNeeded());
 
-    state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+    state.OnBeginImplFrame(
+        CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
     EXPECT_ACTION_UPDATE_STATE(
         SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   }
 
   // Begin the frame, make sure needs_commit and commit_state update correctly.
   {
     StateMachine state(default_scheduler_settings);
     state.SetCanStart();
     state.UpdateState(state.NextAction());
     state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
@@ skipping 16 matching lines @@
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetNeedsRedraw(false);
   state.SetVisible(true);
   state.SetCanDraw(true);
   state.SetNeedsCommit();
 
   EXPECT_TRUE(state.BeginFrameNeeded());
 
   // Commit to the pending tree.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   state.NotifyBeginMainFrameStarted();
   state.NotifyReadyToCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
 
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Verify that the next commit starts while there is still a pending tree.
   state.SetNeedsCommit();
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Verify the pending commit doesn't overwrite the pending
   // tree until the pending tree has been activated.
   state.NotifyBeginMainFrameStarted();
   state.NotifyReadyToCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
@@ skipping 20 matching lines @@
   SchedulerSettings default_scheduler_settings;
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
   state.SetNeedsRedraw(true);
   EXPECT_TRUE(state.RedrawPending());
   EXPECT_TRUE(state.BeginFrameNeeded());
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.OnBeginImplFrameDeadline();
 
   // We're drawing now.
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
   state.DidSwapBuffers();
   state.DidSwapBuffersComplete();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   EXPECT_FALSE(state.RedrawPending());
   EXPECT_FALSE(state.CommitPending());
 
   // Failing the draw makes us require a commit.
   state.DidDrawIfPossibleCompleted(DRAW_ABORTED_CHECKERBOARD_ANIMATIONS);
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_TRUE(state.RedrawPending());
   EXPECT_TRUE(state.CommitPending());
 }
 
 TEST(SchedulerStateMachineTest, TestFailedDrawForMissingHighResNeedsCommit) {
   SchedulerSettings default_scheduler_settings;
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
   state.SetNeedsRedraw(true);
   EXPECT_TRUE(state.RedrawPending());
   EXPECT_TRUE(state.BeginFrameNeeded());
 
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
   state.DidSwapBuffers();
   state.DidSwapBuffersComplete();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   EXPECT_FALSE(state.RedrawPending());
   EXPECT_FALSE(state.CommitPending());
 
   // Missing high res content requires a commit (but not a redraw)
   state.DidDrawIfPossibleCompleted(DRAW_ABORTED_MISSING_HIGH_RES_CONTENT);
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_FALSE(state.RedrawPending());
   EXPECT_TRUE(state.CommitPending());
 }
 
 TEST(SchedulerStateMachineTest,
      TestsetNeedsRedrawDuringFailedDrawDoesNotRemoveNeedsRedraw) {
   SchedulerSettings default_scheduler_settings;
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
 
   state.SetVisible(true);
   state.SetCanDraw(true);
   state.SetNeedsRedraw(true);
   EXPECT_TRUE(state.RedrawPending());
   EXPECT_TRUE(state.BeginFrameNeeded());
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.OnBeginImplFrameDeadline();
 
   // We're drawing now.
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
   state.DidSwapBuffers();
   state.DidSwapBuffersComplete();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   EXPECT_FALSE(state.RedrawPending());
   EXPECT_FALSE(state.CommitPending());
 
   // While still in the same BeginMainFrame callback on the main thread,
   // set needs redraw again. This should not redraw.
   state.SetNeedsRedraw(true);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Failing the draw for animation checkerboards makes us require a commit.
   state.DidDrawIfPossibleCompleted(DRAW_ABORTED_CHECKERBOARD_ANIMATIONS);
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_TRUE(state.RedrawPending());
 }
 
 TEST(SchedulerStateMachineTest,
      TestFailedDrawsEventuallyForceDrawAfterNextCommit) {
   SchedulerSettings scheduler_settings;
   scheduler_settings.maximum_number_of_failed_draws_before_draw_is_forced_ = 1;
   StateMachine state(scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   // Start a commit.
   state.SetNeedsCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   EXPECT_TRUE(state.CommitPending());
 
   // Then initiate a draw.
   state.SetNeedsRedraw(true);
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
 
   // Fail the draw.
   state.DidDrawIfPossibleCompleted(DRAW_ABORTED_CHECKERBOARD_ANIMATIONS);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   EXPECT_TRUE(state.BeginFrameNeeded());
   EXPECT_TRUE(state.RedrawPending());
   // But the commit is ongoing.
   EXPECT_TRUE(state.CommitPending());
 
   // Finish the commit. Note, we should not yet be forcing a draw, but should
   // continue the commit as usual.
   state.NotifyBeginMainFrameStarted();
   state.NotifyReadyToCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   EXPECT_TRUE(state.RedrawPending());
 
   // The redraw should be forced at the end of the next BeginImplFrame.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_FORCED);
   state.DidSwapBuffers();
   state.DidSwapBuffersComplete();
 }
 
 TEST(SchedulerStateMachineTest, TestFailedDrawsDoNotRestartForcedDraw) {
   SchedulerSettings scheduler_settings;
   int draw_limit = 1;
   scheduler_settings.maximum_number_of_failed_draws_before_draw_is_forced_ =
       draw_limit;
   scheduler_settings.impl_side_painting = true;
   StateMachine state(scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   // Start a commit.
   state.SetNeedsCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   EXPECT_TRUE(state.CommitPending());
 
   // Then initiate a draw.
   state.SetNeedsRedraw(true);
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(
@@ skipping 36 matching lines @@
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   // Start a draw.
   state.SetNeedsRedraw(true);
   EXPECT_TRUE(state.BeginFrameNeeded());
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.OnBeginImplFrameDeadline();
   EXPECT_TRUE(state.RedrawPending());
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
 
   // Failing the draw for animation checkerboards makes us require a commit.
   state.DidDrawIfPossibleCompleted(DRAW_ABORTED_CHECKERBOARD_ANIMATIONS);
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   EXPECT_TRUE(state.RedrawPending());
 
   // We should not be trying to draw again now, but we have a commit pending.
   EXPECT_TRUE(state.BeginFrameNeeded());
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // We should try to draw again at the end of the next BeginImplFrame on
   // the impl thread.
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
   state.DidSwapBuffers();
   state.DidSwapBuffersComplete();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 }
 
 TEST(SchedulerStateMachineTest, TestDoestDrawTwiceInSameFrame) {
   SchedulerSettings default_scheduler_settings;
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
   state.SetNeedsRedraw(true);
 
   // Draw the first frame.
   EXPECT_TRUE(state.BeginFrameNeeded());
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
   state.DidSwapBuffers();
   state.DidDrawIfPossibleCompleted(DRAW_SUCCESS);
   state.DidSwapBuffersComplete();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Before the next BeginImplFrame, set needs redraw again.
   // This should not redraw until the next BeginImplFrame.
   state.SetNeedsRedraw(true);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Move to another frame. This should now draw.
   EXPECT_TRUE(state.BeginFrameNeeded());
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
 
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
   state.DidSwapBuffers();
   state.DidDrawIfPossibleCompleted(DRAW_SUCCESS);
   state.DidSwapBuffersComplete();
@@ skipping 117 matching lines @@
     // There shouldn't be any drawing regardless of BeginImplFrame.
     for (size_t j = 0; j < 2; ++j) {
       StateMachine state(default_scheduler_settings);
       state.SetCanStart();
       state.UpdateState(state.NextAction());
       state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
       state.SetCommitState(all_commit_states[i]);
       state.SetVisible(false);
       state.SetNeedsRedraw(true);
       if (j == 1)
-        state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+        state.OnBeginImplFrame(
+            CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
 
       state.SetCanDraw(false);
       EXPECT_NE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE,
                 state.NextAction());
     }
   }
 }
 
 TEST(SchedulerStateMachineTest,
      TestCanRedrawWithWaitingForFirstDrawMakesProgress) {
   SchedulerSettings default_scheduler_settings;
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
 
   state.SetActiveTreeNeedsFirstDraw(true);
   state.SetNeedsCommit();
   state.SetNeedsRedraw(true);
   state.SetVisible(true);
   state.SetCanDraw(false);
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_ABORT);
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.NotifyBeginMainFrameStarted();
   state.NotifyReadyToCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_ABORT);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 }
 
 TEST(SchedulerStateMachineTest, TestSetNeedsCommitIsNotLost) {
   SchedulerSettings scheduler_settings;
   StateMachine state(scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetNeedsCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   EXPECT_TRUE(state.BeginFrameNeeded());
 
   // Begin the frame.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
             state.CommitState());
 
   // Now, while the frame is in progress, set another commit.
   state.SetNeedsCommit();
   EXPECT_TRUE(state.NeedsCommit());
 
   // Let the frame finish.
@@ skipping 15 matching lines @@
   state.OnBeginImplFrameDeadline();
   EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE,
             state.begin_impl_frame_state());
   EXPECT_EQ(SchedulerStateMachine::ACTION_COMMIT, state.NextAction());
 
   state.OnBeginImplFrameIdle();
   EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE,
             state.begin_impl_frame_state());
   EXPECT_EQ(SchedulerStateMachine::ACTION_COMMIT, state.NextAction());
 
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING,
             state.begin_impl_frame_state());
   EXPECT_EQ(SchedulerStateMachine::ACTION_COMMIT, state.NextAction());
 
   // Finish the commit, then make sure we start the next commit immediately
   // and draw on the next BeginImplFrame.
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
@@ skipping 16 matching lines @@
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   // Start clean and set commit.
   state.SetNeedsCommit();
 
   // Begin the frame.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
             state.CommitState());
   EXPECT_FALSE(state.NeedsCommit());
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Tell the scheduler the frame finished.
   state.NotifyBeginMainFrameStarted();
   state.NotifyReadyToCommit();
@@ skipping 16 matching lines @@
   state.DidSwapBuffers();
   state.DidDrawIfPossibleCompleted(DRAW_SUCCESS);
   state.DidSwapBuffersComplete();
 
   // Should be synchronized, no draw needed, no action needed.
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
   EXPECT_FALSE(state.needs_redraw());
 }
 
+TEST(SchedulerStateMachineTest, TestFullCycleWithMainThreadLowLatencyMode) {
+  SchedulerSettings scheduler_settings;
+  scheduler_settings.main_thread_should_always_be_low_latency = true;
+  StateMachine state(scheduler_settings);
+  state.SetCanStart();
+  state.UpdateState(state.NextAction());
+  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
+  state.SetVisible(true);
+  state.SetCanDraw(true);
+
+  // Start clean and set commit.
+  state.SetNeedsCommit();
+
+  // Begin the frame.
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
+  EXPECT_ACTION_UPDATE_STATE(
+      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
+  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
+            state.CommitState());
+  EXPECT_FALSE(state.NeedsCommit());
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
+
+  // Tell the scheduler the frame finished.
+  state.NotifyBeginMainFrameStarted();
+  state.NotifyReadyToCommit();
+  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_READY_TO_COMMIT,
+            state.CommitState());
+
+  // Commit.
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
+  EXPECT_TRUE(state.active_tree_needs_first_draw());
+  EXPECT_TRUE(state.needs_redraw());
+
+  // Now commit should wait for draw.
+  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_WAITING_FOR_DRAW,
+            state.CommitState());
+
+  // Swap throttled. Do not draw.
+  state.DidSwapBuffers();
+  state.OnBeginImplFrameDeadline();
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
+  state.DidSwapBuffersComplete();
+
+  // Haven't draw since last commit, do not begin new main frame.
+  state.SetNeedsCommit();
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
+
+  // At BeginImplFrame deadline, draw.
+  state.OnBeginImplFrameDeadline();
+  EXPECT_ACTION_UPDATE_STATE(
+      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
+  state.DidSwapBuffers();
+  state.DidDrawIfPossibleCompleted(DRAW_SUCCESS);
+  state.DidSwapBuffersComplete();
+
+  // Now will be able to start main frame.
+  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
+  EXPECT_FALSE(state.needs_redraw());
+  EXPECT_ACTION_UPDATE_STATE(
+      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
+}
+
+TEST(SchedulerStateMachineTest,
+     TestFullCycleWithMainThreadLowLatencyMode_ImplSidePaint) {
+  SchedulerSettings scheduler_settings;
+  scheduler_settings.main_thread_should_always_be_low_latency = true;
+  scheduler_settings.impl_side_painting = true;
+  StateMachine state(scheduler_settings);
+  state.SetCanStart();
+  state.UpdateState(state.NextAction());
+  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
+  state.SetVisible(true);
+  state.SetCanDraw(true);
+
+  // Start clean and set commit.
+  state.SetNeedsCommit();
+
+  // Begin the frame.
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
+  EXPECT_ACTION_UPDATE_STATE(
+      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
+  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
+            state.CommitState());
+  EXPECT_FALSE(state.NeedsCommit());
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
+
+  // Tell the scheduler the frame finished.
+  state.NotifyBeginMainFrameStarted();
+  state.NotifyReadyToCommit();
+  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_READY_TO_COMMIT,
+            state.CommitState());
+
+  // Commit.
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
+
+  // Now commit should wait for activation.
+  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_WAITING_FOR_ACTIVATION,
+            state.CommitState());
+
+  // No activation yet, so this commit is not drawn yet. Force to draw this
+  // frame, and still block BeginMainFrame.
+  state.SetNeedsRedraw(true);
+  state.SetNeedsCommit();
+  state.OnBeginImplFrameDeadline();
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
+  EXPECT_ACTION_UPDATE_STATE(
+      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
+
+  // Cannot BeginMainFrame yet since last commit is not yet activated and drawn.
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
+  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_WAITING_FOR_ACTIVATION,
+            state.CommitState());
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
+
+  // Now activate sync tree.
+  state.NotifyReadyToActivate();
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ACTIVATE_SYNC_TREE);
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
+  EXPECT_TRUE(state.active_tree_needs_first_draw());
+  EXPECT_TRUE(state.needs_redraw());
+  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_WAITING_FOR_DRAW,
+            state.CommitState());
+
+  // Swap throttled. Do not draw.
+  state.DidSwapBuffers();
+  state.OnBeginImplFrameDeadline();
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
+  state.DidSwapBuffersComplete();
+
+  // Haven't draw since last commit, do not begin new main frame.
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
+  EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
+
+  // At BeginImplFrame deadline, draw. This draws unblocks BeginMainFrame.
+  state.OnBeginImplFrameDeadline();
+  EXPECT_ACTION_UPDATE_STATE(
+      SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
+  state.DidSwapBuffers();
+  state.DidDrawIfPossibleCompleted(DRAW_SUCCESS);
+  state.DidSwapBuffersComplete();
+
+  // Now will be able to start main frame.
+  EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
+  EXPECT_FALSE(state.needs_redraw());
+  EXPECT_ACTION_UPDATE_STATE(
+      SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
+}
+
 TEST(SchedulerStateMachineTest, TestFullCycleWithCommitRequestInbetween) {
   SchedulerSettings default_scheduler_settings;
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   // Start clean and set commit.
   state.SetNeedsCommit();
 
   // Begin the frame.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
             state.CommitState());
   EXPECT_FALSE(state.NeedsCommit());
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Request another commit while the commit is in flight.
   state.SetNeedsCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
@@ skipping 20 matching lines @@
   state.DidSwapBuffers();
   state.DidDrawIfPossibleCompleted(DRAW_SUCCESS);
   state.DidSwapBuffersComplete();
 
   // Should be synchronized, no draw needed, no action needed.
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
   EXPECT_FALSE(state.needs_redraw());
 
   // Next BeginImplFrame should initiate second commit.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
 }
 
 TEST(SchedulerStateMachineTest, TestRequestCommitInvisible) {
   SchedulerSettings default_scheduler_settings;
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetNeedsCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 }
 
 TEST(SchedulerStateMachineTest, TestGoesInvisibleBeforeFinishCommit) {
   SchedulerSettings default_scheduler_settings;
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   // Start clean and set commit.
   state.SetNeedsCommit();
 
   // Begin the frame while visible.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
             state.CommitState());
   EXPECT_FALSE(state.NeedsCommit());
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Become invisible and abort BeginMainFrame.
   state.SetVisible(false);
   state.BeginMainFrameAborted(false);
 
   // We should now be back in the idle state as if we never started the frame.
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // We shouldn't do anything on the BeginImplFrame deadline.
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Become visible again.
   state.SetVisible(true);
 
   // Although we have aborted on this frame and haven't cancelled the commit
   // (i.e. need another), don't send another BeginMainFrame yet.
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
   EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
   EXPECT_TRUE(state.NeedsCommit());
 
   // Start a new frame.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
 
   // We should be starting the commit now.
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
             state.CommitState());
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 }
 
 TEST(SchedulerStateMachineTest, AbortBeginMainFrameAndCancelCommit) {
@@ skipping 18 matching lines @@
   // Abort the commit, cancelling future commits.
   state.BeginMainFrameAborted(true);
 
   // Verify that another commit doesn't start on the same frame.
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
   EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
   EXPECT_FALSE(state.NeedsCommit());
 
   // Start a new frame; draw because this is the first frame since output
   // surface init'd.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
   state.DidSwapBuffers();
   state.DidSwapBuffersComplete();
 
   // Verify another commit doesn't start on another frame either.
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
@@ skipping 31 matching lines @@
   state.SetVisible(false);
   state.BeginMainFrameAborted(true);
 
   // Verify that another commit doesn't start on the same frame.
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
   EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
   EXPECT_FALSE(state.NeedsCommit());
 
   // Become visible and start a new frame.
   state.SetVisible(true);
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Draw because this is the first frame since output surface init'd.
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
   state.DidSwapBuffers();
   state.DidSwapBuffersComplete();
 
@@ skipping 44 matching lines @@
   EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
   EXPECT_TRUE(state.NeedsCommit());
 
   // Become visible but nothing happens until the next frame.
   state.SetVisible(true);
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
   EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
   EXPECT_TRUE(state.NeedsCommit());
 
   // We should get that commit when we begin the next frame.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
 }
 
 TEST(SchedulerStateMachineTest,
      AbortBeginMainFrameAndRequestCommitAndBeginImplFrameWhenInvisible) {
   SchedulerSettings default_scheduler_settings;
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
@@ skipping 16 matching lines @@
   state.SetVisible(false);
   state.BeginMainFrameAborted(true);
 
   // Asking for a commit while not visible won't make it happen.
   state.SetNeedsCommit();
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
   EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
   EXPECT_TRUE(state.NeedsCommit());
 
   // Begin a frame when not visible, the scheduler animates but does not commit.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
   EXPECT_TRUE(state.NeedsCommit());
 
   // Become visible and the requested commit happens immediately.
   state.SetVisible(true);
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_IDLE, state.CommitState());
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
 }
 
 TEST(SchedulerStateMachineTest, TestFirstContextCreation) {
   SchedulerSettings default_scheduler_settings;
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION);
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Check that the first init does not SetNeedsCommit.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Check that a needs commit initiates a BeginMainFrame.
   state.SetNeedsCommit();
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
 }
 
 TEST(SchedulerStateMachineTest, TestContextLostWhenCompletelyIdle) {
   SchedulerSettings default_scheduler_settings;
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
 
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   EXPECT_NE(SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION,
             state.NextAction());
   state.DidLoseOutputSurface();
 
   EXPECT_EQ(SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION,
             state.NextAction());
   state.UpdateState(state.NextAction());
 
   // Once context recreation begins, nothing should happen.
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Recreate the context.
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
 
   // When the context is recreated, we should begin a commit.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
 }
 
 TEST(SchedulerStateMachineTest,
      TestContextLostWhenIdleAndCommitRequestedWhileRecreating) {
   SchedulerSettings default_scheduler_settings;
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   EXPECT_NE(SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION,
             state.NextAction());
   state.DidLoseOutputSurface();
 
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Once context recreation begins, nothing should happen.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // While context is recreating, commits shouldn't begin.
   state.SetNeedsCommit();
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Recreate the context
   state.DidCreateAndInitializeOutputSurface();
   EXPECT_FALSE(state.RedrawPending());
 
   // When the context is recreated, we should begin a commit
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   EXPECT_EQ(SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT,
             state.CommitState());
 
   state.NotifyBeginMainFrameStarted();
   state.NotifyReadyToCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   // Finishing the first commit after initializing an output surface should
   // automatically cause a redraw.
   EXPECT_TRUE(state.RedrawPending());
 
   // Once the context is recreated, whether we draw should be based on
   // SetCanDraw.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.OnBeginImplFrameDeadline();
   EXPECT_EQ(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE,
             state.NextAction());
   state.SetCanDraw(false);
   EXPECT_EQ(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_ABORT,
             state.NextAction());
   state.SetCanDraw(true);
   EXPECT_EQ(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE,
             state.NextAction());
 }
 
 TEST(SchedulerStateMachineTest, TestContextLostWhileCommitInProgress) {
   SchedulerSettings scheduler_settings;
   StateMachine state(scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   // Get a commit in flight.
   state.SetNeedsCommit();
 
   // Set damage and expect a draw.
   state.SetNeedsRedraw(true);
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
   state.DidSwapBuffers();
   state.DidSwapBuffersComplete();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
@@ skipping 14 matching lines @@
   // waiting for the first draw to unblock the main thread.
   EXPECT_TRUE(state.active_tree_needs_first_draw());
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_ABORT);
 
   // Expect to begin context recreation only in BEGIN_IMPL_FRAME_STATE_IDLE
   EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE,
             state.begin_impl_frame_state());
   EXPECT_EQ(SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION,
             state.NextAction());
 
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING,
             state.begin_impl_frame_state());
   EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
 
   state.OnBeginImplFrameDeadlinePending();
   EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME,
             state.begin_impl_frame_state());
   EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
 
   state.OnBeginImplFrameDeadline();
@@ skipping 11 matching lines @@
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   // Get a commit in flight.
   state.SetNeedsCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Set damage and expect a draw.
   state.SetNeedsRedraw(true);
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
   state.DidSwapBuffers();
   state.DidSwapBuffersComplete();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
@@ skipping 14 matching lines @@
 
   // Because the output surface is missing, we expect the draw to abort.
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_DRAW_AND_SWAP_ABORT);
 
   // Expect to begin context recreation only in BEGIN_IMPL_FRAME_STATE_IDLE
   EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE,
             state.begin_impl_frame_state());
   EXPECT_EQ(SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION,
             state.NextAction());
 
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_BEGIN_FRAME_STARTING,
             state.begin_impl_frame_state());
   EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
 
   state.OnBeginImplFrameDeadlinePending();
   EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME,
             state.begin_impl_frame_state());
   EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
 
   state.OnBeginImplFrameDeadline();
   EXPECT_EQ(SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_INSIDE_DEADLINE,
             state.begin_impl_frame_state());
   EXPECT_EQ(SchedulerStateMachine::ACTION_NONE, state.NextAction());
 
   state.OnBeginImplFrameIdle();
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION);
 
   // After we get a new output surface, the commit flow should start.
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.NotifyBeginMainFrameStarted();
   state.NotifyReadyToCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(
@@ skipping 15 matching lines @@
   state.SetNeedsRedraw(true);
 
   // Cause a lost output surface, and restore it.
   state.DidLoseOutputSurface();
   EXPECT_EQ(SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION,
             state.NextAction());
   state.UpdateState(state.NextAction());
   state.DidCreateAndInitializeOutputSurface();
 
   EXPECT_FALSE(state.RedrawPending());
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_EQ(SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME,
             state.NextAction());
 }
 
 TEST(SchedulerStateMachineTest,
      TestPendingActivationsShouldBeForcedAfterLostOutputSurface) {
   SchedulerSettings settings;
   settings.impl_side_painting = true;
   StateMachine state(settings);
   state.SetCanStart();
@@ skipping 111 matching lines @@
   settings.impl_side_painting = true;
   StateMachine state(settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   // This test mirrors what happens during the first frame of a scroll gesture.
   // First we get the input event and a BeginFrame.
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
 
   // As a response the compositor requests a redraw and a commit to tell the
   // main thread about the new scroll offset.
   state.SetNeedsRedraw(true);
   state.SetNeedsCommit();
 
   // We should start the commit normally.
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
@@ skipping 14 matching lines @@
   StateMachine& state = *state_ptr;
 
   state.NotifyBeginMainFrameStarted();
   state.NotifyReadyToCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.NotifyReadyToActivate();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ACTIVATE_SYNC_TREE);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   EXPECT_TRUE(state.ShouldTriggerBeginImplFrameDeadlineEarly());
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
   state.DidSwapBuffers();
 }
 
 TEST(SchedulerStateMachineTest, TestImplLatencyTakesPriority) {
   SchedulerSettings settings;
   settings.impl_side_painting = true;
   StateMachine state(settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   // This test ensures that impl-draws are prioritized over main thread updates
   // in prefer impl latency mode.
   state.SetNeedsRedraw(true);
   state.SetNeedsCommit();
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Verify the deadline is not triggered early until we enter
   // prefer impl latency mode.
   EXPECT_FALSE(state.ShouldTriggerBeginImplFrameDeadlineEarly());
   state.SetImplLatencyTakesPriority(true);
   EXPECT_TRUE(state.ShouldTriggerBeginImplFrameDeadlineEarly());
@@ skipping 16 matching lines @@
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Finish the previous commit and draw it.
   FinishPreviousCommitAndDrawWithoutExitingDeadline(&state);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   // Verify we do not send another BeginMainFrame if was are swap throttled
   // and did not just swap.
   state.SetNeedsCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   EXPECT_FALSE(state.ShouldTriggerBeginImplFrameDeadlineEarly());
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 }
 
 TEST(SchedulerStateMachineTest, TestTriggerDeadlineEarlyOnLostOutputSurface) {
   SchedulerSettings default_scheduler_settings;
   StateMachine state(default_scheduler_settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   state.SetNeedsCommit();
 
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   EXPECT_FALSE(state.ShouldTriggerBeginImplFrameDeadlineEarly());
 
   state.DidLoseOutputSurface();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   // The deadline should be triggered immediately when output surface is lost.
   EXPECT_TRUE(state.ShouldTriggerBeginImplFrameDeadlineEarly());
 }
 
 TEST(SchedulerStateMachineTest, TestSetNeedsAnimate) {
   SchedulerSettings settings;
   settings.impl_side_painting = true;
   StateMachine state(settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   // Test requesting an animation that, when run, causes us to draw.
   state.SetNeedsAnimate();
   EXPECT_TRUE(state.BeginFrameNeeded());
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
 
   state.OnBeginImplFrameDeadlinePending();
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
 }
 
 TEST(SchedulerStateMachineTest, TestAnimateBeforeCommit) {
   SchedulerSettings settings;
   settings.impl_side_painting = true;
   StateMachine state(settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   // Check that animations are updated before we start a commit.
   state.SetNeedsAnimate();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.SetNeedsCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   EXPECT_TRUE(state.BeginFrameNeeded());
 
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
 
   state.OnBeginImplFrameDeadlinePending();
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
 }
 
 TEST(SchedulerStateMachineTest, TestAnimateAfterCommitBeforeDraw) {
   SchedulerSettings settings;
   settings.impl_side_painting = true;
   StateMachine state(settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   // Check that animations are updated before we start a commit.
   state.SetNeedsAnimate();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   state.SetNeedsCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
   EXPECT_TRUE(state.BeginFrameNeeded());
 
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME);
 
   state.NotifyBeginMainFrameStarted();
   state.NotifyReadyToCommit();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_COMMIT);
 
   state.OnBeginImplFrameDeadlinePending();
   state.OnBeginImplFrameDeadline();
@@ skipping 11 matching lines @@
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   // Test requesting an animation after we have already animated during this
   // frame.
   state.SetNeedsRedraw(true);
   EXPECT_TRUE(state.BeginFrameNeeded());
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
-  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting());
+  state.OnBeginImplFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_ANIMATE);
 
   state.SetNeedsAnimate();
   EXPECT_ACTION_UPDATE_STATE(SchedulerStateMachine::ACTION_NONE);
 
   state.OnBeginImplFrameDeadline();
   EXPECT_ACTION_UPDATE_STATE(
       SchedulerStateMachine::ACTION_DRAW_AND_SWAP_IF_POSSIBLE);
 }
 
 TEST(SchedulerStateMachineTest, TestForwardBeginFramesToChildren) {
   SchedulerSettings settings;
   settings.forward_begin_frames_to_children = true;
   StateMachine state(settings);
   state.SetCanStart();
   state.UpdateState(state.NextAction());
   state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
   state.SetVisible(true);
   state.SetCanDraw(true);
 
   EXPECT_FALSE(state.BeginFrameNeeded());
   state.SetChildrenNeedBeginFrames(true);
   EXPECT_TRUE(state.BeginFrameNeeded());
 }
 
 }  // namespace
 }  // namespace cc