cc: Aggressively expire retro frames.

If we're not aggressive about expiring a retro frame (e.g. MISSED
frames) then it's possible to enter a high latency mode often.

PixelTestOutputSurface is used by the ui compositor in tests and we
should not subtract the default estimated parent draw time from the
deadline in that case. Doing so will cause MISSED frames to always
expire in tests.

BUG=469953

Review URL: https://codereview.chromium.org/1055113004

Cr-Commit-Position: refs/heads/master@{#330669}

cc/scheduler/scheduler.cc

@@ -434,7 +434,7 @@ void Scheduler::BeginRetroFrame() {
 
   while (!begin_retro_frame_args_.empty()) {
     const BeginFrameArgs& args = begin_retro_frame_args_.front();
-    base::TimeTicks expiration_time = args.frame_time + args.interval;
+    base::TimeTicks expiration_time = args.deadline;
     if (now <= expiration_time)
       break;
     TRACE_EVENT_INSTANT2(

cc/scheduler/scheduler_unittest.cc

@@ -400,13 +400,15 @@ class SchedulerTest : public testing::Test {
     }
   }
 
-  void SendNextBeginFrame() {
+  BeginFrameArgs SendNextBeginFrame() {
     DCHECK(scheduler_->settings().use_external_begin_frame_source);
     // Creep the time forward so that any BeginFrameArgs is not equal to the
     // last one otherwise we violate the BeginFrameSource contract.
     now_src_->AdvanceNow(BeginFrameArgs::DefaultInterval());
-    fake_external_begin_frame_source_->TestOnBeginFrame(
-        CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE, now_src()));
+    BeginFrameArgs args =
+        CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE, now_src());
+    fake_external_begin_frame_source_->TestOnBeginFrame(args);
+    return args;
   }
 
   FakeExternalBeginFrameSource* fake_external_begin_frame_source() const {
@@ -1606,7 +1608,7 @@ TEST_F(SchedulerTest, RetroFrameDoesNotExpireTooEarly) {
   scheduler_->NotifyBeginMainFrameStarted();
 
   client_->Reset();
-  SendNextBeginFrame();
+  BeginFrameArgs retro_frame_args = SendNextBeginFrame();
   // This BeginFrame is queued up as a retro frame.
   EXPECT_NO_ACTION(client_);
   // The previous deadline is still pending.
@@ -1630,10 +1632,8 @@ TEST_F(SchedulerTest, RetroFrameDoesNotExpireTooEarly) {
   scheduler_->SetNeedsRedraw();
   EXPECT_NO_ACTION(client_);
 
-  // Let's advance sufficiently past the next frame's deadline.
-  now_src()->AdvanceNow(BeginFrameArgs::DefaultInterval() -
-                        BeginFrameArgs::DefaultEstimatedParentDrawTime() +
-                        base::TimeDelta::FromMicroseconds(1));
+  // Let's advance to the retro frame's deadline.
+  now_src()->AdvanceNow(retro_frame_args.deadline - now_src()->Now());
 
   // The retro frame hasn't expired yet.
   task_runner().RunTasksWhile(client_->ImplFrameDeadlinePending(false));
@@ -1648,7 +1648,7 @@ TEST_F(SchedulerTest, RetroFrameDoesNotExpireTooEarly) {
   EXPECT_SINGLE_ACTION("ScheduledActionDrawAndSwapIfPossible", client_);
 }
 
-TEST_F(SchedulerTest, RetroFrameDoesNotExpireTooLate) {
+TEST_F(SchedulerTest, RetroFrameExpiresOnTime) {
   scheduler_settings_.use_external_begin_frame_source = true;
   SetUpScheduler(true);
 
@@ -1666,7 +1666,7 @@ TEST_F(SchedulerTest, RetroFrameDoesNotExpireTooLate) {
   scheduler_->NotifyBeginMainFrameStarted();
 
   client_->Reset();
-  SendNextBeginFrame();
+  BeginFrameArgs retro_frame_args = SendNextBeginFrame();
   // This BeginFrame is queued up as a retro frame.
   EXPECT_NO_ACTION(client_);
   // The previous deadline is still pending.
@@ -1690,14 +1690,64 @@ TEST_F(SchedulerTest, RetroFrameDoesNotExpireTooLate) {
   scheduler_->SetNeedsRedraw();
   EXPECT_NO_ACTION(client_);
 
-  // Let's advance sufficiently past the next frame's deadline.
-  now_src()->AdvanceNow(BeginFrameArgs::DefaultInterval() +
+  // Let's advance sufficiently past the retro frame's deadline.
+  now_src()->AdvanceNow(retro_frame_args.deadline - now_src()->Now() +
                         base::TimeDelta::FromMicroseconds(1));
 
   // The retro frame should've expired.
   EXPECT_NO_ACTION(client_);
 }
 
+TEST_F(SchedulerTest, MissedFrameDoesNotExpireTooEarly) {
+  scheduler_settings_.use_external_begin_frame_source = true;
+  SetUpScheduler(true);
+
+  scheduler_->SetNeedsCommit();
+  EXPECT_TRUE(client_->needs_begin_frames());
+  EXPECT_SINGLE_ACTION("SetNeedsBeginFrames(true)", client_);
+
+  BeginFrameArgs missed_frame_args =
+      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE, now_src());
+  missed_frame_args.type = BeginFrameArgs::MISSED;
+
+  // Advance to the deadline.
+  now_src()->AdvanceNow(missed_frame_args.deadline - now_src()->Now());
+
+  // Missed frame is handled because it's on time.
+  client_->Reset();
+  fake_external_begin_frame_source_->TestOnBeginFrame(missed_frame_args);
+  EXPECT_TRUE(
+      task_runner().RunTasksWhile(client_->ImplFrameDeadlinePending(false)));
+  EXPECT_ACTION("WillBeginImplFrame", client_, 0, 2);
+  EXPECT_ACTION("ScheduledActionSendBeginMainFrame", client_, 1, 2);
+  EXPECT_TRUE(scheduler_->BeginImplFrameDeadlinePending());
+}
+
+TEST_F(SchedulerTest, MissedFrameExpiresOnTime) {
+  scheduler_settings_.use_external_begin_frame_source = true;
+  SetUpScheduler(true);
+
+  scheduler_->SetNeedsCommit();
+  EXPECT_TRUE(client_->needs_begin_frames());
+  EXPECT_SINGLE_ACTION("SetNeedsBeginFrames(true)", client_);
+
+  BeginFrameArgs missed_frame_args =
+      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE, now_src());
+  missed_frame_args.type = BeginFrameArgs::MISSED;
+
+  // Advance sufficiently past the deadline.
+  now_src()->AdvanceNow(missed_frame_args.deadline - now_src()->Now() +
+                        base::TimeDelta::FromMicroseconds(1));
+
+  // Missed frame is dropped because it's too late.
+  client_->Reset();
+  fake_external_begin_frame_source_->TestOnBeginFrame(missed_frame_args);
+  EXPECT_FALSE(
+      task_runner().RunTasksWhile(client_->ImplFrameDeadlinePending(false)));
+  EXPECT_NO_ACTION(client_);
+  EXPECT_FALSE(scheduler_->BeginImplFrameDeadlinePending());
+}
+
 void SchedulerTest::BeginFramesNotFromClient(
     bool use_external_begin_frame_source,
     bool throttle_frame_production) {

cc/test/pixel_test_output_surface.cc

@@ -15,6 +15,7 @@ PixelTestOutputSurface::PixelTestOutputSurface(
     bool flipped_output_surface)
     : OutputSurface(context_provider, worker_context_provider),
       external_stencil_test_(false) {
+  capabilities_.adjust_deadline_for_parent = false;
   capabilities_.flipped_output_surface = flipped_output_surface;
 }