[cc/metrics] Do not report latency metrics for Universal sequence.

It is not necessary to report the various latency metrics for the
Universal sequence, since the un-prefixed metric is equivalent.

BUG=none

Change-Id: I82caf09752288e6dbfe3c2781be1668e0d2a10af
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1996154
Commit-Queue: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: Behdad Bakhshinategh <behdadb@chromium.org>
Auto-Submit: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#731836}

cc/metrics/compositor_frame_reporter.cc

@@ -127,10 +127,17 @@ constexpr int kHistogramMin = 1;
 constexpr int kHistogramMax = 350000;
 constexpr int kHistogramBucketCount = 50;
 
+bool ShouldReportLatencyMetricsForSequenceType(
+    FrameSequenceTrackerType sequence_type) {
+  return sequence_type != FrameSequenceTrackerType::kUniversal;
+}
+
 std::string HistogramName(const int report_type_index,
                           FrameSequenceTrackerType frame_sequence_tracker_type,
                           const int stage_type_index) {
   DCHECK_LE(frame_sequence_tracker_type, FrameSequenceTrackerType::kMaxType);
+  DCHECK(
+      ShouldReportLatencyMetricsForSequenceType(frame_sequence_tracker_type));
   const char* tracker_type_name =
       FrameSequenceTracker::GetFrameSequenceTrackerTypeName(
           frame_sequence_tracker_type);
@@ -298,6 +305,8 @@ void CompositorFrameReporter::ReportStageHistogramWithBreakdown(
     CompositorFrameReporter::MissedFrameReportTypes report_type,
     const CompositorFrameReporter::StageData& stage,
     FrameSequenceTrackerType frame_sequence_tracker_type) const {
+  if (!ShouldReportLatencyMetricsForSequenceType(frame_sequence_tracker_type))
+    return;
   base::TimeDelta stage_delta = stage.end_time - stage.start_time;
   ReportHistogram(report_type, frame_sequence_tracker_type,
                   static_cast<int>(stage.stage_type), stage_delta);

cc/test/layer_tree_test.cc

@@ -1037,8 +1037,10 @@ void LayerTreeTest::RunTest(CompositorMode mode) {
       std::make_unique<viz::TestGpuMemoryBufferManager>();
   task_graph_runner_.reset(new TestTaskGraphRunner);
 
-  if (mode == CompositorMode::THREADED)
+  if (mode == CompositorMode::THREADED) {
     settings_.commit_to_active_tree = false;
+    settings_.single_thread_proxy_scheduler = false;
+  }
   // Disable latency recovery to make the scheduler more predictable in its
   // actions and less dependent on timings to make decisions.
   settings_.enable_latency_recovery = false;

cc/trees/layer_tree_host_unittest_animation.cc

@@ -8,6 +8,7 @@
 #include <climits>
 
 #include "base/bind.h"
+#include "base/metrics/statistics_recorder.h"
 #include "cc/animation/animation.h"
 #include "cc/animation/animation_curve.h"
 #include "cc/animation/animation_host.h"
@@ -1044,6 +1045,10 @@ class LayerTreeHostPresentationDuringAnimation
     EXPECT_GT(request_token_, 0u);
     EXPECT_GT(received_token_, request_token_);
     EXPECT_GE(received_token_, 5u);
+    EXPECT_TRUE(base::StatisticsRecorder::FindHistogram(
+        "CompositorLatency.TotalLatency"));
+    EXPECT_FALSE(base::StatisticsRecorder::FindHistogram(
+        "CompositorLatency.Universal.TotalLatency"));
   }
 
  private: