Add an overall metric for scrolling via touch/wheel

Measure the scrolling performance regardless of
whether touch or wheel input triggered the scrolling.

Bug: 842846
Change-Id: I04750f3537f4da326e9a2f3c0e16e895bc696c2a
Reviewed-on: https://chromium-review.googlesource.com/1059583Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Reviewed-by: Sahel Sharifymoghaddam <sahel@chromium.org>
Reviewed-by: Timothy Dresser <tdresser@chromium.org>
Commit-Queue: Navid Zolghadr <nzolghadr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558774}

content/browser/renderer_host/input/render_widget_host_latency_tracker_unittest.cc

@@ -248,6 +248,14 @@ TEST_F(RenderWidgetHostLatencyTrackerTest, TestWheelToFirstScrollHistograms) {
           total_ukm_entry_count);
 
       // UMA histograms.
+      EXPECT_TRUE(
+          HistogramSizeEq("Event.Latency.ScrollBegin."
+                          "TimeToScrollUpdateSwapBegin",
+                          1));
+      EXPECT_TRUE(
+          HistogramSizeEq("Event.Latency.ScrollUpdate."
+                          "TimeToScrollUpdateSwapBegin",
+                          0));
       EXPECT_TRUE(
           HistogramSizeEq("Event.Latency.ScrollBegin.Wheel."
                           "TimeToScrollUpdateSwapBegin2",
@@ -344,6 +352,14 @@ TEST_F(RenderWidgetHostLatencyTrackerTest, TestWheelToScrollHistograms) {
           total_ukm_entry_count);
 
       // UMA histograms.
+      EXPECT_TRUE(
+          HistogramSizeEq("Event.Latency.ScrollBegin."
+                          "TimeToScrollUpdateSwapBegin",
+                          0));
+      EXPECT_TRUE(
+          HistogramSizeEq("Event.Latency.ScrollUpdate."
+                          "TimeToScrollUpdateSwapBegin",
+                          1));
       EXPECT_TRUE(
           HistogramSizeEq("Event.Latency.ScrollBegin.Wheel."
                           "TimeToScrollUpdateSwapBegin2",
@@ -463,6 +479,14 @@ TEST_F(RenderWidgetHostLatencyTrackerTest, TestTouchToFirstScrollHistograms) {
         total_ukm_entry_count);
 
     // UMA histograms.
+    EXPECT_TRUE(
+        HistogramSizeEq("Event.Latency.ScrollBegin."
+                        "TimeToScrollUpdateSwapBegin",
+                        1));
+    EXPECT_TRUE(
+        HistogramSizeEq("Event.Latency.ScrollUpdate."
+                        "TimeToScrollUpdateSwapBegin",
+                        0));
     EXPECT_TRUE(HistogramSizeEq(
         "Event.Latency.ScrollBegin.Touch.TimeToScrollUpdateSwapBegin2", 1));
 
@@ -565,6 +589,14 @@ TEST_F(RenderWidgetHostLatencyTrackerTest, TestTouchToScrollHistograms) {
         total_ukm_entry_count);
 
     // UMA histograms.
+    EXPECT_TRUE(
+        HistogramSizeEq("Event.Latency.ScrollBegin."
+                        "TimeToScrollUpdateSwapBegin",
+                        0));
+    EXPECT_TRUE(
+        HistogramSizeEq("Event.Latency.ScrollUpdate."
+                        "TimeToScrollUpdateSwapBegin",
+                        1));
     EXPECT_TRUE(HistogramSizeEq(
         "Event.Latency.ScrollBegin.Touch.TimeToScrollUpdateSwapBegin2", 0));
     EXPECT_TRUE(HistogramSizeEq(

tools/metrics/histograms/histograms.xml

@@ -22837,6 +22837,20 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Event.Latency.ScrollBegin.TimeToScrollUpdateSwapBegin"
+    units="microseconds">
+  <owner>nzolghadr@chromium.org</owner>
+  <summary>
+    Time between initial creation of a wheel/touch event and start of the frame
+    swap on the GPU service caused by the generated ScrollUpdate gesture event
+    if that ScrollUpdate is the first such event in a given scroll gesture event
+    sequence. If no swap was induced by the event, no recording is made. If no
+    swap was induced by the event, no recording is made.
+
+    Team: input-dev@chromium.org.
+  </summary>
+</histogram>
+
 <histogram
     name="Event.Latency.ScrollBegin.Touch.BrowserNotifiedToBeforeGpuSwap2"
     units="microseconds">
@@ -23043,6 +23057,19 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Event.Latency.ScrollUpdate.TimeToScrollUpdateSwapBegin"
+    units="microseconds">
+  <owner>nzolghadr@chromium.org</owner>
+  <summary>
+    Time between initial creation of a wheel/touch event and start of the frame
+    swap on the GPU service caused by the generated ScrollUpdate gesture event.
+    If no swap was induced by the event, no recording is made. The first GSU of
+    every scrolling sequence is excluded from this metric.
+
+    Team: input-dev@chromium.org.
+  </summary>
+</histogram>
+
 <histogram
     name="Event.Latency.ScrollUpdate.Touch.BrowserNotifiedToBeforeGpuSwap2"
     units="microseconds">

ui/latency/latency_histogram_macros.h

@@ -12,7 +12,7 @@
   DCHECK(!start.first_event_time.is_null());  \
   DCHECK(!end.last_event_time.is_null());
 
-// Event latency that is mostly under 1 second. We should only use 100 buckets
+// Event latency that is mostly under 2 seconds. We should only use 100 buckets
 // when needed.
 #define UMA_HISTOGRAM_INPUT_LATENCY_HIGH_RESOLUTION_MICROSECONDS(name, start, \
                                                                  end)         \
@@ -22,7 +22,7 @@
       std::max(                                                               \
           static_cast<int64_t>(0),                                            \
           (end.last_event_time - start.first_event_time).InMicroseconds()),   \
-      1, 1000000, 100);
+      1, 2000000, 100);
 
 #define UMA_HISTOGRAM_INPUT_LATENCY_MILLISECONDS(name, start, end)          \
   CONFIRM_EVENT_TIMES_EXIST(start, end)                                     \

ui/latency/latency_tracker.cc

@@ -175,6 +175,13 @@ void LatencyTracker::ComputeEndToEndLatencyHistograms(
           &original_component)) {
     scroll_name = "ScrollBegin";
     DCHECK(input_modality == "Wheel" || input_modality == "Touch");
+
+    // This UMA metric tracks the performance of overall scrolling as a high
+    // level metric.
+    UMA_HISTOGRAM_INPUT_LATENCY_HIGH_RESOLUTION_MICROSECONDS(
+        "Event.Latency.ScrollBegin.TimeToScrollUpdateSwapBegin",
+        original_component, gpu_swap_begin_component);
+
     // This UMA metric tracks the time between the final frame swap for the
     // first scroll event in a sequence and the original timestamp of that
     // scroll event's underlying touch/wheel event.
@@ -193,6 +200,13 @@ void LatencyTracker::ComputeEndToEndLatencyHistograms(
                  &original_component)) {
     scroll_name = "ScrollUpdate";
     DCHECK(input_modality == "Wheel" || input_modality == "Touch");
+
+    // This UMA metric tracks the performance of overall scrolling as a high
+    // level metric.
+    UMA_HISTOGRAM_INPUT_LATENCY_HIGH_RESOLUTION_MICROSECONDS(
+        "Event.Latency.ScrollUpdate.TimeToScrollUpdateSwapBegin",
+        original_component, gpu_swap_begin_component);
+
     // This UMA metric tracks the time from when the original touch/wheel event
     // is created to when the scroll gesture results in final frame swap.
     // First scroll events are excluded from this metric.