Bug 1698643 - Implement a telemetry probe to collect the input latency from mouseup(followed by a click) to the next composition r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D108647

dom/events/EventDispatcher.cpp

@@ -1101,14 +1101,30 @@ nsresult EventDispatcher::Dispatch(nsISupports* aTarget,
         }
         aEvent->mPath = nullptr;
 
-        if (aEvent->mMessage == eKeyPress && aEvent->IsTrusted()) {
-          if (aPresContext && aPresContext->GetRootPresContext()) {
-            nsRefreshDriver* driver =
-                aPresContext->GetRootPresContext()->RefreshDriver();
-            if (driver && driver->HasPendingTick()) {
-              driver->RegisterCompositionPayload(
-                  {layers::CompositionPayloadType::eKeyPress,
-                   aEvent->mTimeStamp});
+        if (aPresContext && aPresContext->GetRootPresContext() &&
+            aEvent->IsTrusted()) {
+          nsRefreshDriver* driver =
+              aPresContext->GetRootPresContext()->RefreshDriver();
+          if (driver && driver->HasPendingTick()) {
+            switch (aEvent->mMessage) {
+              case eKeyPress:
+                driver->RegisterCompositionPayload(
+                    {layers::CompositionPayloadType::eKeyPress,
+                     aEvent->mTimeStamp});
+                break;
+              case eMouseClick: {
+                if (aEvent->AsMouseEvent()->mInputSource ==
+                        MouseEvent_Binding::MOZ_SOURCE_MOUSE ||
+                    aEvent->AsMouseEvent()->mInputSource ==
+                        MouseEvent_Binding::MOZ_SOURCE_TOUCH) {
+                  driver->RegisterCompositionPayload(
+                      {layers::CompositionPayloadType::eMouseUpFollowedByClick,
+                       aEvent->mTimeStamp});
+                }
+                break;
+              }
+              default:
+                break;
             }
           }
         }

gfx/layers/Layers.cpp

@@ -2241,6 +2241,11 @@ void RecordCompositionPayloadsPresented(
         Telemetry::AccumulateTimeDelta(
             mozilla::Telemetry::SCROLL_PRESENT_LATENCY, payload.mTimeStamp,
             presented);
+      } else if (payload.mType ==
+                 CompositionPayloadType::eMouseUpFollowedByClick) {
+        Telemetry::AccumulateTimeDelta(
+            mozilla::Telemetry::MOUSEUP_FOLLOWED_BY_CLICK_PRESENT_LATENCY,
+            payload.mTimeStamp, presented);
       }
     }
   }

gfx/layers/LayersTypes.h

@@ -423,7 +423,15 @@ MOZ_DEFINE_ENUM_CLASS_WITH_BASE(CompositionPayloadType, uint8_t, (
    * A |CompositionPayload| with this type indicates that content was painted
    * that will be included in the composition.
    */
-  eContentPaint
+  eContentPaint,
+
+  /**
+   * A |CompositionPayload| with this type indicates a mouse up (which caused
+   * a click to happen) happened before composition and will be used to determine latency
+   * between mouse up and presentation in
+   * |mozilla::Telemetry::MOUSEUP_FOLLOWED_BY_CLICK_PRESENT_LATENCY|
+   */
+  eMouseUpFollowedByClick
 ));
 // clang-format on
 

toolkit/components/telemetry/Histograms.json

@@ -1714,6 +1714,19 @@
     "description": "Time between receiving a keypress event on the event loop and compositing its result onto the screen (ms)",
     "bug_numbers": [1506537, 1580077]
   },
+  "MOUSEUP_FOLLOWED_BY_CLICK_PRESENT_LATENCY": {
+    "record_in_processes": [ "main", "gpu" ],
+    "products": ["firefox", "geckoview_streaming"],
+    "alert_emails": [ "perf-telemetry-alerts@mozilla.com", "sefeng@mozilla.com" ],
+    "expires_in_version": "never",
+    "kind": "exponential",
+    "releaseChannelCollection": "opt-out",
+    "low": 1,
+    "high": 200000,
+    "n_buckets": 50,
+    "description": "Time between receiving a mouseup which follow by a mouseclick on the event loop and compositing its result onto the screen (ms)",
+    "bug_numbers": [1698643]
+  },
   "SCROLL_PRESENT_LATENCY": {
     "record_in_processes": ["main", "gpu"],
     "products": ["firefox", "geckoview_streaming"],

toolkit/components/telemetry/geckoview/streaming/metrics.yaml

@@ -1351,6 +1351,22 @@ performance.interaction:
       - vchin@mozilla.com
     expires: never
 
+  mouseup_click_present_latency:
+    type: timing_distribution
+    time_unit: millisecond
+    gecko_datapoint: MOUSEUP_FOLLOWED_BY_CLICK_PRESENT_LATENCY
+    description: >
+      Time between receiving a mouseup which follow by a mouseclick
+      on the event loop and compositing its result onto the screen.
+    bugs:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1698643
+    data_reviews:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1698643#c3
+    notification_emails:
+      - perf-telemetry-alerts@mozilla.com
+      - sefeng@mozilla.com
+    expires: never
+
   tab_switch_composite:
     type: timing_distribution
     time_unit: millisecond