cc: Track BeginMainFrame more precisely in CompositorTimingHistory.

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 34726d5ddf8795792d6f0fa7a85aeef5ba9193de..8c1bbe366d61c1201e2c4296103e698435ee5f47 100644
--- a/cc/scheduler/compositor_timing_history.cc
+++ b/cc/scheduler/compositor_timing_history.cc
@@ -17,6 +17,15 @@ class CompositorTimingHistory::UMAReporter {
   virtual void AddBeginMainFrameToCommitDuration(base::TimeDelta duration,
                                                  base::TimeDelta estimate,
                                                  bool affects_estimate) = 0;
+  virtual void AddBeginMainFrameQueueDurationCriticalDuration(
+      base::TimeDelta duration,
+      bool affects_estimate) = 0;
+  virtual void AddBeginMainFrameQueueDurationNotCriticalDuration(
+      base::TimeDelta duration,
+      bool affects_estimate) = 0;
+  virtual void AddBeginMainFrameStartToCommitDuration(
+      base::TimeDelta duration,
+      bool affects_estimate) = 0;
   virtual void AddCommitToReadyToActivateDuration(base::TimeDelta duration,
                                                   base::TimeDelta estimate,
                                                   bool affects_estimate) = 0;
@@ -39,6 +48,9 @@ namespace {
 // TODO(brianderson): Fine tune the percentiles below.
 const size_t kDurationHistorySize = 60;
 const double kBeginMainFrameToCommitEstimationPercentile = 90.0;
+const double kBeginMainFrameQueueDurationCriticalEstimationPercentile = 90.0;
+const double kBeginMainFrameQueueDurationNotCriticalEstimationPercentile = 90.0;
+const double kBeginMainFrameStartToCommitEstimationPercentile = 90.0;
 const double kCommitToReadyToActivateEstimationPercentile = 90.0;
 const double kPrepareTilesEstimationPercentile = 90.0;
 const double kActivateEstimationPercentile = 90.0;
@@ -77,6 +89,7 @@ void DeprecatedDrawDurationUMA(base::TimeDelta duration,
                               kUmaDurationMinMicros, kUmaDurationMaxMicros, \
                               kUmaDurationBucketCount);
 
+// Records over/under estimates.
 #define REPORT_COMPOSITOR_TIMING_HISTORY_UMA(category, subcategory)            \
   do {                                                                         \
     base::TimeDelta duration_overestimate;                                     \
@@ -100,6 +113,18 @@ void DeprecatedDrawDurationUMA(base::TimeDelta duration,
     }                                                                          \
   } while (false)
 
+// Does not record over/under estimates.
+#define REPORT_COMPOSITOR_TIMING_HISTORY_UMA2(category, subcategory)           \
+  do {                                                                         \
+    UMA_HISTOGRAM_CUSTOM_TIMES_MICROS("Scheduling." category "." subcategory,  \
+                                      duration);                               \
+    if (!affects_estimate) {                                                   \
+      UMA_HISTOGRAM_CUSTOM_TIMES_MICROS("Scheduling." category "." subcategory \
+                                        ".NotUsedForEstimate",                 \
+                                        duration);                             \
+    }                                                                          \
+  } while (false)
+
 class RendererUMAReporter : public CompositorTimingHistory::UMAReporter {
  public:
   ~RendererUMAReporter() override {}
@@ -110,6 +135,26 @@ class RendererUMAReporter : public CompositorTimingHistory::UMAReporter {
     REPORT_COMPOSITOR_TIMING_HISTORY_UMA("Renderer", "BeginMainFrameToCommit");
   }
 
+  void AddBeginMainFrameQueueDurationCriticalDuration(
+      base::TimeDelta duration,
+      bool affects_estimate) override {
+    REPORT_COMPOSITOR_TIMING_HISTORY_UMA2(
+        "Renderer", "BeginMainFrameQueueDurationCritical");
+  }
+
+  void AddBeginMainFrameQueueDurationNotCriticalDuration(
+      base::TimeDelta duration,
+      bool affects_estimate) override {
+    REPORT_COMPOSITOR_TIMING_HISTORY_UMA2(
+        "Renderer", "BeginMainFrameQueueDurationNotCritical");
+  }
+
+  void AddBeginMainFrameStartToCommitDuration(base::TimeDelta duration,
+                                              bool affects_estimate) override {
+    REPORT_COMPOSITOR_TIMING_HISTORY_UMA2(
+        "Renderer", "BeginMainFrameStartToCommitDuration");
+  }
+
   void AddCommitToReadyToActivateDuration(base::TimeDelta duration,
                                           base::TimeDelta estimate,
                                           bool affects_estimate) override {
@@ -146,6 +191,26 @@ class BrowserUMAReporter : public CompositorTimingHistory::UMAReporter {
     REPORT_COMPOSITOR_TIMING_HISTORY_UMA("Browser", "BeginMainFrameToCommit");
   }
 
+  void AddBeginMainFrameQueueDurationCriticalDuration(
+      base::TimeDelta duration,
+      bool affects_estimate) override {
+    REPORT_COMPOSITOR_TIMING_HISTORY_UMA2(
+        "Browser", "BeginMainFrameQueueDurationCritical");
+  }
+
+  void AddBeginMainFrameQueueDurationNotCriticalDuration(
+      base::TimeDelta duration,
+      bool affects_estimate) override {
+    REPORT_COMPOSITOR_TIMING_HISTORY_UMA2(
+        "Browser", "BeginMainFrameQueueDurationNotCritical");
+  }
+
+  void AddBeginMainFrameStartToCommitDuration(base::TimeDelta duration,
+                                              bool affects_estimate) override {
+    REPORT_COMPOSITOR_TIMING_HISTORY_UMA2("Browser",
+                                          "BeginMainFrameStartToCommit");
+  }
+
   void AddCommitToReadyToActivateDuration(base::TimeDelta duration,
                                           base::TimeDelta estimate,
                                           bool affects_estimate) override {
@@ -175,15 +240,23 @@ class BrowserUMAReporter : public CompositorTimingHistory::UMAReporter {
 class NullUMAReporter : public CompositorTimingHistory::UMAReporter {
  public:
   ~NullUMAReporter() override {}
-  void AddPrepareTilesDuration(base::TimeDelta duration,
-                               base::TimeDelta estimate,
-                               bool affects_estimate) override {}
   void AddBeginMainFrameToCommitDuration(base::TimeDelta duration,
                                          base::TimeDelta estimate,
                                          bool affects_estimate) override {}
+  void AddBeginMainFrameQueueDurationCriticalDuration(
+      base::TimeDelta duration,
+      bool affects_estimate) override {}
+  void AddBeginMainFrameQueueDurationNotCriticalDuration(
+      base::TimeDelta duration,
+      bool affects_estimate) override {}
+  void AddBeginMainFrameStartToCommitDuration(base::TimeDelta duration,
+                                              bool affects_estimate) override {}
   void AddCommitToReadyToActivateDuration(base::TimeDelta duration,
                                           base::TimeDelta estimate,
                                           bool affects_estimate) override {}
+  void AddPrepareTilesDuration(base::TimeDelta duration,
+                               base::TimeDelta estimate,
+                               bool affects_estimate) override {}
   void AddActivateDuration(base::TimeDelta duration,
                            base::TimeDelta estimate,
                            bool affects_estimate) override {}
@@ -198,11 +271,16 @@ CompositorTimingHistory::CompositorTimingHistory(
     UMACategory uma_category,
     RenderingStatsInstrumentation* rendering_stats_instrumentation)
     : enabled_(false),
-      begin_main_frame_to_commit_duration_history_(kDurationHistorySize),
+      begin_main_frame_sent_to_commit_duration_history_(kDurationHistorySize),
+      begin_main_frame_queue_duration_critical_history_(kDurationHistorySize),
+      begin_main_frame_queue_duration_not_critical_history_(
+          kDurationHistorySize),
+      begin_main_frame_start_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),
+      begin_main_frame_on_critical_path_(false),
       uma_reporter_(CreateUMAReporter(uma_category)),
       rendering_stats_instrumentation_(rendering_stats_instrumentation) {}
 
@@ -250,11 +328,30 @@ void CompositorTimingHistory::SetRecordingEnabled(bool enabled) {
 
 base::TimeDelta
 CompositorTimingHistory::BeginMainFrameToCommitDurationEstimate() const {
-  return begin_main_frame_to_commit_duration_history_.Percentile(
+  return begin_main_frame_sent_to_commit_duration_history_.Percentile(
       kBeginMainFrameToCommitEstimationPercentile);
 }
 
 base::TimeDelta
+CompositorTimingHistory::BeginMainFrameQueueDurationCriticalEstimate() const {
+  return begin_main_frame_queue_duration_critical_history_.Percentile(
+      kBeginMainFrameQueueDurationCriticalEstimationPercentile);
+}
+
+base::TimeDelta
+CompositorTimingHistory::BeginMainFrameQueueDurationNotCriticalEstimate()
+    const {
+  return begin_main_frame_queue_duration_not_critical_history_.Percentile(
+      kBeginMainFrameQueueDurationNotCriticalEstimationPercentile);
+}
+
+base::TimeDelta
+CompositorTimingHistory::BeginMainFrameStartToCommitDurationEstimate() const {
+  return begin_main_frame_start_to_commit_duration_history_.Percentile(
+      kBeginMainFrameStartToCommitEstimationPercentile);
+}
+
+base::TimeDelta
 CompositorTimingHistory::CommitToReadyToActivateDurationEstimate() const {
   return commit_to_ready_to_activate_duration_history_.Percentile(
       kCommitToReadyToActivateEstimationPercentile);
@@ -273,11 +370,19 @@ base::TimeDelta CompositorTimingHistory::DrawDurationEstimate() const {
   return draw_duration_history_.Percentile(kDrawEstimationPercentile);
 }
 
-void CompositorTimingHistory::WillBeginMainFrame() {
+void CompositorTimingHistory::WillBeginMainFrame(bool on_critical_path) {
   DCHECK_EQ(base::TimeTicks(), begin_main_frame_sent_time_);
+  begin_main_frame_on_critical_path_ = on_critical_path;
   begin_main_frame_sent_time_ = Now();
 }
 
+void CompositorTimingHistory::BeginMainFrameStarted(
+    base::TimeTicks main_thread_start_time) {
+  DCHECK_NE(base::TimeTicks(), begin_main_frame_sent_time_);
+  DCHECK_EQ(base::TimeTicks(), begin_main_frame_start_time_);
+  begin_main_frame_start_time_ = main_thread_start_time;
+}
+
 void CompositorTimingHistory::BeginMainFrameAborted() {
   DidCommit();
 }
@@ -287,26 +392,62 @@ void CompositorTimingHistory::DidCommit() {
 
   commit_time_ = Now();
 
-  base::TimeDelta begin_main_frame_to_commit_duration =
+  // If the BeginMainFrame start time isn't know, assume it was immediate
+  // for scheduling purposes, but don't report it for UMA to avoid skewing
+  // the results.
+  bool begin_main_frame_start_time_is_valid =
+      !begin_main_frame_start_time_.is_null();
+  if (!begin_main_frame_start_time_is_valid)
+    begin_main_frame_start_time_ = begin_main_frame_sent_time_;
+
+  base::TimeDelta begin_main_frame_sent_to_commit_duration =
       commit_time_ - begin_main_frame_sent_time_;
+  base::TimeDelta begin_main_frame_queue_duration =
+      begin_main_frame_start_time_ - begin_main_frame_sent_time_;
+  base::TimeDelta begin_main_frame_start_to_commit_duration =
+      commit_time_ - begin_main_frame_start_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.
-  base::TimeDelta begin_main_frame_to_commit_estimate =
+  base::TimeDelta begin_main_frame_sent_to_commit_estimate =
       BeginMainFrameToCommitDurationEstimate();
   uma_reporter_->AddBeginMainFrameToCommitDuration(
-      begin_main_frame_to_commit_duration, begin_main_frame_to_commit_estimate,
-      enabled_);
+      begin_main_frame_sent_to_commit_duration,
+      begin_main_frame_sent_to_commit_estimate, enabled_);
   rendering_stats_instrumentation_->AddBeginMainFrameToCommitDuration(
-      begin_main_frame_to_commit_duration, begin_main_frame_to_commit_estimate);
+      begin_main_frame_sent_to_commit_duration,
+      begin_main_frame_sent_to_commit_estimate);
+
+  if (begin_main_frame_start_time_is_valid) {
+    if (begin_main_frame_on_critical_path_) {
+      uma_reporter_->AddBeginMainFrameQueueDurationCriticalDuration(
+          begin_main_frame_queue_duration, enabled_);
+    } else {
+      uma_reporter_->AddBeginMainFrameQueueDurationNotCriticalDuration(
+          begin_main_frame_queue_duration, enabled_);
+    }
+  }
+
+  uma_reporter_->AddBeginMainFrameStartToCommitDuration(
+      begin_main_frame_start_to_commit_duration, enabled_);
 
   if (enabled_) {
-    begin_main_frame_to_commit_duration_history_.InsertSample(
-        begin_main_frame_to_commit_duration);
+    begin_main_frame_sent_to_commit_duration_history_.InsertSample(
+        begin_main_frame_sent_to_commit_duration);
+    if (begin_main_frame_on_critical_path_) {
+      begin_main_frame_queue_duration_critical_history_.InsertSample(
+          begin_main_frame_queue_duration);
+    } else {
+      begin_main_frame_queue_duration_not_critical_history_.InsertSample(
+          begin_main_frame_queue_duration);
+    }
+    begin_main_frame_start_to_commit_duration_history_.InsertSample(
+        begin_main_frame_start_to_commit_duration);
   }
 
   begin_main_frame_sent_time_ = base::TimeTicks();
+  begin_main_frame_start_time_ = base::TimeTicks();
 }
 
 void CompositorTimingHistory::WillPrepareTiles() {