fix startup timings computation in timer service

src/vs/workbench/services/timer/browser/timerService.ts

@@ -8,7 +8,7 @@ import { createDecorator } from 'vs/platform/instantiation/common/instantiation'
 import { IWorkspaceContextService, WorkbenchState } from 'vs/platform/workspace/common/workspace';
 import { IExtensionService } from 'vs/workbench/services/extensions/common/extensions';
 import { IUpdateService } from 'vs/platform/update/common/update';
-import { ILifecycleService } from 'vs/platform/lifecycle/common/lifecycle';
+import { ILifecycleService, LifecyclePhase } from 'vs/platform/lifecycle/common/lifecycle';
 import { IViewletService } from 'vs/workbench/services/viewlet/browser/viewlet';
 import { IPanelService } from 'vs/workbench/services/panel/common/panelService';
 import { IEditorService } from 'vs/workbench/services/editor/common/editorService';
@@ -320,7 +320,10 @@ export abstract class AbstractTimerService implements ITimerService {
 		@IAccessibilityService private readonly _accessibilityService: IAccessibilityService,
 		@ITelemetryService private readonly _telemetryService: ITelemetryService,
 	) {
-		this._startupMetrics = this._extensionService.whenInstalledExtensionsRegistered()
+		this._startupMetrics = Promise.all([
+			this._extensionService.whenInstalledExtensionsRegistered(),
+			_lifecycleService.when(LifecyclePhase.Restored)
+		])
 			.then(() => this._computeStartupMetrics())
 			.then(metrics => {
 				this._reportStartupTimes(metrics);