Revert of cc: Measure compositor timing with finer granularity

cc/scheduler/compositor_timing_history.cc

Index: cc/scheduler/compositor_timing_history.cc
diff --git a/cc/scheduler/compositor_timing_history.cc b/cc/scheduler/compositor_timing_history.cc
index 67b7f29dcfdc2c756a4b086029ea4a5d468a3cb6..7dcd9eacf03d6c70fdff64d85a026f4733018f98 100644
--- a/cc/scheduler/compositor_timing_history.cc
+++ b/cc/scheduler/compositor_timing_history.cc
@@ -8,28 +8,18 @@
 #include "base/trace_event/trace_event.h"
 #include "cc/debug/rendering_stats_instrumentation.h"
 
-// The estimates that affect the compositors deadline use the 100th percentile
-// to avoid missing the Browser's deadline.
-// The estimates related to main-thread responsiveness affect whether
-// we attempt to recovery latency or not and use the 50th percentile.
-// TODO(brianderson): Fine tune the percentiles below.
 const size_t kDurationHistorySize = 60;
-const double kBeginMainFrameToCommitEstimationPercentile = 50.0;
-const double kCommitToReadyToActivateEstimationPercentile = 50.0;
-const double kPrepareTilesEstimationPercentile = 100.0;
-const double kActivateEstimationPercentile = 100.0;
-const double kDrawEstimationPercentile = 100.0;
+const double kCommitAndActivationDurationEstimationPercentile = 50.0;
+const double kDrawDurationEstimationPercentile = 100.0;
+const int kDrawDurationEstimatePaddingInMicroseconds = 0;
 
 namespace cc {
 
 CompositorTimingHistory::CompositorTimingHistory(
     RenderingStatsInstrumentation* rendering_stats_instrumentation)
-    : enabled_(false),
+    : draw_duration_history_(kDurationHistorySize),
       begin_main_frame_to_commit_duration_history_(kDurationHistorySize),
-      commit_to_ready_to_activate_duration_history_(kDurationHistorySize),
-      prepare_tiles_duration_history_(kDurationHistorySize),
-      activate_duration_history_(kDurationHistorySize),
-      draw_duration_history_(kDurationHistorySize),
+      commit_to_activate_duration_history_(kDurationHistorySize),
       rendering_stats_instrumentation_(rendering_stats_instrumentation) {
 }
 
@@ -40,73 +30,40 @@
     base::trace_event::TracedValue* state) const {
   state->SetDouble("begin_main_frame_to_commit_duration_estimate_ms",
                    BeginMainFrameToCommitDurationEstimate().InMillisecondsF());
-  state->SetDouble("commit_to_ready_to_activate_duration_estimate_ms",
-                   CommitToReadyToActivateDurationEstimate().InMillisecondsF());
-  state->SetDouble("prepare_tiles_duration_estimate_ms",
-                   PrepareTilesDurationEstimate().InMillisecondsF());
-  state->SetDouble("activate_duration_estimate_ms",
-                   ActivateDurationEstimate().InMillisecondsF());
+  state->SetDouble("commit_to_activate_duration_estimate_ms",
+                   CommitToActivateDurationEstimate().InMillisecondsF());
   state->SetDouble("draw_duration_estimate_ms",
                    DrawDurationEstimate().InMillisecondsF());
 }
 
-base::TimeTicks CompositorTimingHistory::Now() const {
-  return base::TimeTicks::Now();
-}
-
-void CompositorTimingHistory::SetRecordingEnabled(bool enabled) {
-  enabled_ = enabled;
-
-  if (enabled) {
-    begin_main_frame_sent_time_ = base::TimeTicks();
-    commit_time_ = base::TimeTicks();
-    start_prepare_tiles_time_ = base::TimeTicks();
-    start_activate_time_ = base::TimeTicks();
-    start_draw_time_ = base::TimeTicks();
-  }
+base::TimeDelta CompositorTimingHistory::DrawDurationEstimate() const {
+  base::TimeDelta historical_estimate =
+      draw_duration_history_.Percentile(kDrawDurationEstimationPercentile);
+  base::TimeDelta padding = base::TimeDelta::FromMicroseconds(
+      kDrawDurationEstimatePaddingInMicroseconds);
+  return historical_estimate + padding;
 }
 
 base::TimeDelta
 CompositorTimingHistory::BeginMainFrameToCommitDurationEstimate() const {
   return begin_main_frame_to_commit_duration_history_.Percentile(
-      kBeginMainFrameToCommitEstimationPercentile);
+      kCommitAndActivationDurationEstimationPercentile);
 }
 
-base::TimeDelta
-CompositorTimingHistory::CommitToReadyToActivateDurationEstimate() const {
-  return commit_to_ready_to_activate_duration_history_.Percentile(
-      kCommitToReadyToActivateEstimationPercentile);
-}
-
-base::TimeDelta CompositorTimingHistory::PrepareTilesDurationEstimate() const {
-  return prepare_tiles_duration_history_.Percentile(
-      kPrepareTilesEstimationPercentile);
-}
-
-base::TimeDelta CompositorTimingHistory::ActivateDurationEstimate() const {
-  return activate_duration_history_.Percentile(kActivateEstimationPercentile);
-}
-
-base::TimeDelta CompositorTimingHistory::DrawDurationEstimate() const {
-  return draw_duration_history_.Percentile(kDrawEstimationPercentile);
+base::TimeDelta CompositorTimingHistory::CommitToActivateDurationEstimate()
+    const {
+  return commit_to_activate_duration_history_.Percentile(
+      kCommitAndActivationDurationEstimationPercentile);
 }
 
 void CompositorTimingHistory::WillBeginMainFrame() {
-  DCHECK_EQ(base::TimeTicks(), begin_main_frame_sent_time_);
-  begin_main_frame_sent_time_ = Now();
-}
-
-void CompositorTimingHistory::BeginMainFrameAborted() {
-  DidCommit();
+  begin_main_frame_sent_time_ = base::TimeTicks::Now();
 }
 
 void CompositorTimingHistory::DidCommit() {
-  DCHECK_NE(base::TimeTicks(), begin_main_frame_sent_time_);
-
-  commit_time_ = Now();
-
+  commit_complete_time_ = base::TimeTicks::Now();
   base::TimeDelta begin_main_frame_to_commit_duration =
-      commit_time_ - begin_main_frame_sent_time_;
+      commit_complete_time_ - begin_main_frame_sent_time_;
 
   // Before adding the new data point to the timing history, see what we would
   // have predicted for this frame. This allows us to keep track of the accuracy
@@ -115,74 +72,30 @@
       begin_main_frame_to_commit_duration,
       BeginMainFrameToCommitDurationEstimate());
 
-  if (enabled_) {
-    begin_main_frame_to_commit_duration_history_.InsertSample(
-        begin_main_frame_to_commit_duration);
-  }
-
-  begin_main_frame_sent_time_ = base::TimeTicks();
+  begin_main_frame_to_commit_duration_history_.InsertSample(
+      begin_main_frame_to_commit_duration);
 }
 
-void CompositorTimingHistory::WillPrepareTiles() {
-  DCHECK_EQ(base::TimeTicks(), start_prepare_tiles_time_);
-  start_prepare_tiles_time_ = Now();
-}
-
-void CompositorTimingHistory::DidPrepareTiles() {
-  DCHECK_NE(base::TimeTicks(), start_prepare_tiles_time_);
-
-  if (enabled_) {
-    base::TimeDelta prepare_tiles_duration = Now() - start_prepare_tiles_time_;
-    prepare_tiles_duration_history_.InsertSample(prepare_tiles_duration);
-  }
-
-  start_prepare_tiles_time_ = base::TimeTicks();
-}
-
-void CompositorTimingHistory::ReadyToActivate() {
-  // We only care about the first ready to activate signal
-  // after a commit.
-  if (commit_time_ == base::TimeTicks())
-    return;
-
-  base::TimeDelta time_since_commit = Now() - commit_time_;
+void CompositorTimingHistory::DidActivateSyncTree() {
+  base::TimeDelta commit_to_activate_duration =
+      base::TimeTicks::Now() - commit_complete_time_;
 
   // Before adding the new data point to the timing history, see what we would
   // have predicted for this frame. This allows us to keep track of the accuracy
   // of our predictions.
   rendering_stats_instrumentation_->AddCommitToActivateDuration(
-      time_since_commit, CommitToReadyToActivateDurationEstimate());
+      commit_to_activate_duration, CommitToActivateDurationEstimate());
 
-  if (enabled_) {
-    commit_to_ready_to_activate_duration_history_.InsertSample(
-        time_since_commit);
-  }
-
-  commit_time_ = base::TimeTicks();
+  commit_to_activate_duration_history_.InsertSample(
+      commit_to_activate_duration);
 }
 
-void CompositorTimingHistory::WillActivate() {
-  DCHECK_EQ(base::TimeTicks(), start_activate_time_);
-  start_activate_time_ = Now();
+void CompositorTimingHistory::DidStartDrawing() {
+  start_draw_time_ = base::TimeTicks::Now();
 }
 
-void CompositorTimingHistory::DidActivate() {
-  DCHECK_NE(base::TimeTicks(), start_activate_time_);
-  if (enabled_) {
-    base::TimeDelta activate_duration = Now() - start_activate_time_;
-    activate_duration_history_.InsertSample(activate_duration);
-  }
-  start_activate_time_ = base::TimeTicks();
-}
-
-void CompositorTimingHistory::WillDraw() {
-  DCHECK_EQ(base::TimeTicks(), start_draw_time_);
-  start_draw_time_ = Now();
-}
-
-void CompositorTimingHistory::DidDraw() {
-  DCHECK_NE(base::TimeTicks(), start_draw_time_);
-  base::TimeDelta draw_duration = Now() - start_draw_time_;
+void CompositorTimingHistory::DidFinishDrawing() {
+  base::TimeDelta draw_duration = base::TimeTicks::Now() - start_draw_time_;
 
   // Before adding the new data point to the timing history, see what we would
   // have predicted for this frame. This allows us to keep track of the accuracy
@@ -193,11 +106,7 @@
 
   AddDrawDurationUMA(draw_duration, draw_duration_estimate);
 
-  if (enabled_) {
-    draw_duration_history_.InsertSample(draw_duration);
-  }
-
-  start_draw_time_ = base::TimeTicks();
+  draw_duration_history_.InsertSample(draw_duration);
 }
 
 void CompositorTimingHistory::AddDrawDurationUMA(