Deprecate Event.Latency.OS.* for Event.Latency.OS2.*

The new metric is correct on Windows, has a wider range so that fewer
samples land in the overflow bucket, and has a millisecond granularity
instead of microsecond.

Also removes the Event.Latency.OS_WIN.* metrics that were used to
validate this code.

Bug: 1189656
Change-Id: I555459596c3ed4f47a874ed27c943f254e230577
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2840587
Reviewed-by: Gabriel Charette <gab@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Commit-Queue: Joe Mason <joenotcharles@chromium.org>
Cr-Commit-Position: refs/heads/master@{#878451}

content/browser/android/content_ui_event_handler.cc

@@ -16,6 +16,7 @@
 #include "ui/events/android/key_event_android.h"
 #include "ui/events/android/motion_event_android.h"
 #include "ui/events/base_event_utils.h"
+#include "ui/events/event_utils.h"
 
 using base::android::AttachCurrentThread;
 using base::android::JavaParamRef;
@@ -99,9 +100,7 @@ void ContentUiEventHandler::SendMouseWheelEvent(
   base::TimeTicks current_time = ui::EventTimeForNow();
   base::TimeTicks event_time =
       base::TimeTicks() + base::TimeDelta::FromMilliseconds(time_ms);
-  base::TimeDelta delta = current_time - event_time;
-  UMA_HISTOGRAM_CUSTOM_COUNTS("Event.Latency.OS.MOUSE_WHEEL",
-                              delta.InMicroseconds(), 1, 1000000, 50);
+  ComputeEventLatencyOS(ui::ET_MOUSEWHEEL, event_time, current_time);
   ui::MotionEventAndroid::Pointer pointer(
       0, x, y, 0.0f /* touch_major */, 0.0f /* touch_minor */, 0.0f, 0.0f, 0);
 

content/browser/renderer_host/render_widget_host_view_android.cc

@@ -92,6 +92,7 @@
 #include "ui/events/blink/blink_features.h"
 #include "ui/events/blink/did_overscroll_params.h"
 #include "ui/events/blink/web_input_event_traits.h"
+#include "ui/events/event_utils.h"
 #include "ui/events/gesture_detection/gesture_provider_config_helper.h"
 #include "ui/gfx/android/view_configuration.h"
 #include "ui/gfx/codec/jpeg_codec.h"
@@ -2304,25 +2305,24 @@ void RenderWidgetHostViewAndroid::OnStylusSelectTap(base::TimeTicks time,
 void RenderWidgetHostViewAndroid::ComputeEventLatencyOSTouchHistograms(
       const ui::MotionEvent& event) {
   base::TimeTicks event_time = event.GetEventTime();
-  base::TimeDelta delta = base::TimeTicks::Now() - event_time;
+  base::TimeTicks current_time = base::TimeTicks::Now();
+  ui::EventType event_type;
   switch (event.GetAction()) {
     case ui::MotionEvent::Action::DOWN:
     case ui::MotionEvent::Action::POINTER_DOWN:
-      UMA_HISTOGRAM_CUSTOM_COUNTS("Event.Latency.OS.TOUCH_PRESSED",
-                                  delta.InMicroseconds(), 1, 1000000, 50);
-      return;
+      event_type = ui::ET_TOUCH_PRESSED;
+      break;
     case ui::MotionEvent::Action::MOVE:
-      UMA_HISTOGRAM_CUSTOM_COUNTS("Event.Latency.OS.TOUCH_MOVED",
-                                  delta.InMicroseconds(), 1, 1000000, 50);
-      return;
+      event_type = ui::ET_TOUCH_MOVED;
+      break;
     case ui::MotionEvent::Action::UP:
     case ui::MotionEvent::Action::POINTER_UP:
-      UMA_HISTOGRAM_CUSTOM_COUNTS("Event.Latency.OS.TOUCH_RELEASED",
-                                  delta.InMicroseconds(), 1, 1000000, 50);
-      return;
+      event_type = ui::ET_TOUCH_RELEASED;
+      break;
     default:
       return;
   }
+  ui::ComputeEventLatencyOS(event_type, event_time, current_time);
 }
 
 void RenderWidgetHostViewAndroid::CreateOverscrollControllerIfPossible() {

content/browser/renderer_host/render_widget_host_view_mac_unittest.mm

@@ -1697,7 +1697,7 @@ void SendEndPinchEvent() {
   base::HistogramTester histogram_tester;
 
   // Send an initial wheel event for scrolling by 3 lines.
-  // Verify that Event.Latency.OS.MOUSE_WHEEL histogram is computed properly.
+  // Verify that Event.Latency.OS2.MOUSE_WHEEL histogram is computed properly.
   NSEvent* wheelEvent = MockScrollWheelEventWithPhase(@selector(phaseBegan),3);
   [rwhv_mac_->GetInProcessNSView() scrollWheel:wheelEvent];
 
@@ -1708,6 +1708,7 @@ void SendEndPinchEvent() {
       blink::mojom::InputEventResultState::kConsumed);
 
   histogram_tester.ExpectTotalCount("Event.Latency.OS.MOUSE_WHEEL", 1);
+  histogram_tester.ExpectTotalCount("Event.Latency.OS2.MOUSE_WHEEL", 1);
 }
 
 // This test verifies that |selected_text_| is updated accordingly with

tools/metrics/histograms/histograms_xml/event/histograms.xml

@@ -380,13 +380,14 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   </summary>
 </histogram>
 
-<histogram name="Event.Latency.OS" units="microseconds"
-    expires_after="2021-12-01">
+<histogram name="Event.Latency.OS" units="microseconds" expires_after="M92">
   <owner>flackr@chromium.org</owner>
   <owner>input-dev@chromium.org</owner>
   <summary>
     Time between input event received by OS and sent to Chrome, recorded for
-    each event when it is received by Chrome.
+    each event when it is received by Chrome. This is obsoleted by
+    Event.Latency.OS2 and should be removed after they've been run side-by-side
+    for M92.
 
     Warning: This metric may include reports from clients with low-resolution
     clocks (i.e. on Windows, ref. |TimeTicks::IsHighResolution()|). Such reports
@@ -396,6 +397,21 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   </summary>
 </histogram>
 
+<histogram name="Event.Latency.OS2" units="ms" expires_after="2021-12-01">
+  <owner>flackr@chromium.org</owner>
+  <owner>input-dev@chromium.org</owner>
+  <summary>
+    Time between input event received by OS and sent to Chrome, recorded for
+    each event when it is received by Chrome.
+
+    Warning: On Windows, the timestamps of most events come from a clock with a
+    several msec resolution so will have an abnormal distribution even when
+    TimeTicks::IsHighResolution returns true. The exception is touch events
+    which usually come from the high-resolution clock when
+    TimeTicks::IsHighResolution returns true.
+  </summary>
+</histogram>
+
 <histogram name="Event.Latency.OS_NO_VALIDATION.POSITIVE" units="ms"
     expires_after="2021-08-09">
   <owner>sullivan@chromium.org</owner>
@@ -404,14 +420,17 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
     For Mac, a version of Event.Latency.OS that has the positive values it would
     contain if ValidateEventTimeClock() were not called on the timestamps.
 
-    This metric is intended to debug http://crbug.com/1039833, where very high
+    This metric is intended to debug http://crbug.com/1039833 where very high
     numbers are seen for PageLoad.InputDelay3. The units of this metric are the
     same as PageLoad.InputDelay3 for consistency while debugging.
   </summary>
 </histogram>
 
 <histogram name="Event.Latency.OS_WIN.HIGH_RES" units="ms"
     expires_after="2021-12-01">
+  <obsolete>
+    Removed 2021-04-22 - replaced by Event.Latency.OS2.
+  </obsolete>
   <owner>joenotcharles@chromium.org</owner>
   <owner>catan-team@chromium.org</owner>
   <summary>
@@ -434,6 +453,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="Event.Latency.OS_WIN.LOW_RES" units="ms"
     expires_after="2021-12-01">
+  <obsolete>
+    Removed 2021-04-22 - replaced by Event.Latency.OS2.
+  </obsolete>
   <owner>joenotcharles@chromium.org</owner>
   <owner>catan-team@chromium.org</owner>
   <summary>
@@ -456,6 +478,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="Event.Latency.OS_WIN_IS_VALID" enum="Boolean"
     expires_after="2021-12-01">
+  <obsolete>
+    Removed 2021-04-22 - replaced by Event.Latency.OS2.
+  </obsolete>
   <owner>joenotcharles@chromium.org</owner>
   <owner>catan-team@chromium.org</owner>
   <summary>

tools/metrics/histograms/histograms_xml/histogram_suffixes_list.xml

@@ -6333,11 +6333,24 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   <suffix name="TOUCH_PRESSED" label=""/>
   <suffix name="TOUCH_RELEASED" label=""/>
   <affected-histogram name="Event.Latency.OS"/>
+  <affected-histogram name="Event.Latency.OS2"/>
   <affected-histogram name="Event.Latency.OS_NO_VALIDATION.NEGATIVE"/>
   <affected-histogram name="Event.Latency.OS_NO_VALIDATION.POSITIVE"/>
-  <affected-histogram name="Event.Latency.OS_WIN.HIGH_RES"/>
-  <affected-histogram name="Event.Latency.OS_WIN.LOW_RES"/>
-  <affected-histogram name="Event.Latency.OS_WIN_IS_VALID"/>
+  <affected-histogram name="Event.Latency.OS_WIN.HIGH_RES">
+    <obsolete>
+      Removed 2021-04-22 - replaced by Event.Latency.OS2.
+    </obsolete>
+  </affected-histogram>
+  <affected-histogram name="Event.Latency.OS_WIN.LOW_RES">
+    <obsolete>
+      Removed 2021-04-22 - replaced by Event.Latency.OS2.
+    </obsolete>
+  </affected-histogram>
+  <affected-histogram name="Event.Latency.OS_WIN_IS_VALID">
+    <obsolete>
+      Removed 2021-04-22 - replaced by Event.Latency.OS2.
+    </obsolete>
+  </affected-histogram>
 </histogram_suffixes>
 
 <histogram_suffixes name="EventLatencyPinchTypes" separator=".">

ui/events/cocoa/events_mac.mm

@@ -84,6 +84,11 @@ int EventFlagsFromNative(const PlatformEvent& event) {
   return timestamp;
 }
 
+base::TimeTicks EventLatencyTimeFromNative(const PlatformEvent& native_event,
+                                           base::TimeTicks current_time) {
+  return EventTimeFromNative(native_event);
+}
+
 gfx::PointF EventLocationFromNative(const PlatformEvent& native_event) {
   NSWindow* window = [native_event window];
   NSPoint location = [native_event locationInWindow];