Add reporting of checks fetch latency

Change-Id: I0455409e593f7fff68fce83404f917834ad677d7
diff --git a/polygerrit-ui/app/services/app-context-init.ts b/polygerrit-ui/app/services/app-context-init.ts
index dab894e..9af86d2 100644
--- a/polygerrit-ui/app/services/app-context-init.ts
+++ b/polygerrit-ui/app/services/app-context-init.ts
@@ -73,7 +73,7 @@
     authService: () => new Auth(appContext.eventEmitter),
     restApiService: () => new GrRestApiInterface(appContext.authService),
     changeService: () => new ChangeService(),
-    checksService: () => new ChecksService(),
+    checksService: () => new ChecksService(appContext.reportingService),
     jsApiService: () => new GrJsApiInterface(),
     storageService: () => new GrStorageService(),
     configService: () => new ConfigService(),
diff --git a/polygerrit-ui/app/services/checks/checks-service.ts b/polygerrit-ui/app/services/checks/checks-service.ts
index 250cea5..c517fb89 100644
--- a/polygerrit-ui/app/services/checks/checks-service.ts
+++ b/polygerrit-ui/app/services/checks/checks-service.ts
@@ -54,6 +54,7 @@
 import {getCurrentRevision} from '../../utils/change-util';
 import {getShaByPatchNum} from '../../utils/patch-set-util';
 import {assertIsDefined} from '../../utils/common-util';
+import {ReportingService} from '../gr-reporting/gr-reporting';
 
 export class ChecksService {
   private readonly providers: {[name: string]: ChecksProvider} = {};
@@ -64,7 +65,7 @@
 
   private readonly documentVisibilityChange$ = new BehaviorSubject(undefined);
 
-  constructor() {
+  constructor(readonly reporting: ReportingService) {
     checkToPluginMap$.subscribe(map => {
       this.checkToPluginMap = map;
     });
@@ -150,8 +151,7 @@
               commmitMessage: getCurrentRevision(change)?.commit?.message,
               changeInfo: change,
             };
-            updateStateSetLoading(pluginName);
-            return from(this.providers[pluginName].fetch(data));
+            return this.fetchResults(pluginName, data);
           }
         ),
         catchError(e => {
@@ -183,4 +183,16 @@
         }
       });
   }
+
+  private fetchResults(pluginName: string, data: ChangeData) {
+    updateStateSetLoading(pluginName);
+    const timer = this.reporting.getTimer('ChecksPluginFetch');
+    const fetchPromise = this.providers[pluginName]
+      .fetch(data)
+      .then(response => {
+        timer.end({pluginName});
+        return response;
+      });
+    return from(fetchPromise);
+  }
 }
diff --git a/polygerrit-ui/app/services/gr-reporting/gr-reporting.ts b/polygerrit-ui/app/services/gr-reporting/gr-reporting.ts
index d7081ce..bbdb02a 100644
--- a/polygerrit-ui/app/services/gr-reporting/gr-reporting.ts
+++ b/polygerrit-ui/app/services/gr-reporting/gr-reporting.ts
@@ -24,7 +24,7 @@
 
 export interface Timer {
   reset(): this;
-  end(): this;
+  end(eventDetails?: EventDetails): this;
   withMaximum(maximum: number): this;
 }
 
diff --git a/polygerrit-ui/app/services/gr-reporting/gr-reporting_impl.ts b/polygerrit-ui/app/services/gr-reporting/gr-reporting_impl.ts
index 5fd4234..4e6ece2 100644
--- a/polygerrit-ui/app/services/gr-reporting/gr-reporting_impl.ts
+++ b/polygerrit-ui/app/services/gr-reporting/gr-reporting_impl.ts
@@ -713,7 +713,7 @@
       },
 
       // Stop the timer and report the intervening time.
-      end: () => {
+      end: (eventDetails?: EventDetails) => {
         if (called) {
           throw new Error(`Timer for "${name}" already ended.`);
         }
@@ -725,7 +725,7 @@
           return timer;
         }
 
-        this._reportTiming(name, time);
+        this._reportTiming(name, time, eventDetails);
         return timer;
       },