track when all startup resources are loaded

Author: vzaidman

front_end/core/host/RNPerfMetrics.ts

@@ -186,6 +186,15 @@ class RNPerfMetrics {
     });
   }
 
+  developerResourcesStartupLoadingFinishedEvent(count: number): void {
+    this.sendEvent({
+      eventName: 'DeveloperResources.StartupLoadingFinished',
+      params: {
+        count,
+      },
+    });
+  }
+
   fuseboxSetClientMetadataStarted(): void {
     this.sendEvent({eventName: 'FuseboxSetClientMetadataStarted'});
   }
@@ -437,6 +446,13 @@ export type DeveloperResourceLoadingFinishedEvent = Readonly<{
   }>,
 }>;
 
+export type DeveloperResourcesStartupLoadingFinishedEvent = Readonly<{
+  eventName: 'DeveloperResources.StartupLoadingFinished',
+  params: Readonly<{
+    count: number,
+  }>,
+}>;
+
 export type FuseboxSetClientMetadataStartedEvent = Readonly<{
   eventName: 'FuseboxSetClientMetadataStarted',
 }>;
@@ -525,10 +541,10 @@ export type ManualBreakpointSetSucceeded = Readonly<{
 
 export type ReactNativeChromeDevToolsEvent =
     EntrypointLoadingStartedEvent|EntrypointLoadingFinishedEvent|DebuggerReadyEvent|BrowserVisibilityChangeEvent|
-    BrowserErrorEvent|RemoteDebuggingTerminatedEvent|DeveloperResourceLoadingStartedEvent|
-    DeveloperResourceLoadingFinishedEvent|FuseboxSetClientMetadataStartedEvent|FuseboxSetClientMetadataFinishedEvent|
-    MemoryPanelActionStartedEvent|MemoryPanelActionFinishedEvent|PanelShownEvent|PanelClosedEvent|
-    StackTraceSymbolicationSucceeded|StackTraceSymbolicationFailed|StackTraceFrameUrlResolutionSucceeded|
-    StackTraceFrameUrlResolutionFailed|ManualBreakpointSetSucceeded|StackTraceFrameClicked;
+    BrowserErrorEvent|RemoteDebuggingTerminatedEvent|DeveloperResourceLoadingStartedEvent|StackTraceFrameClicked|
+    DeveloperResourceLoadingFinishedEvent|DeveloperResourcesStartupLoadingFinishedEvent|FuseboxSetClientMetadataStartedEvent|
+    FuseboxSetClientMetadataFinishedEvent|MemoryPanelActionStartedEvent|MemoryPanelActionFinishedEvent|
+    PanelShownEvent|PanelClosedEvent|StackTraceSymbolicationSucceeded|StackTraceSymbolicationFailed|
+    StackTraceFrameUrlResolutionSucceeded|StackTraceFrameUrlResolutionFailed|ManualBreakpointSetSucceeded;
 
 export type DecoratedReactNativeChromeDevToolsEvent = CommonEventFields&ReactNativeChromeDevToolsEvent;

front_end/core/sdk/PageResourceLoader.ts

@@ -82,6 +82,7 @@ interface LoadQueueEntry {
  */
 export class PageResourceLoader extends Common.ObjectWrapper.ObjectWrapper<EventTypes> {
   #currentlyLoading = 0;
+  #reportedStartupResourcesLoaded = false;
   #currentlyLoadingPerTarget = new Map<Protocol.Target.TargetID|'main', number>();
   readonly #maxConcurrentLoads: number;
   #pageResources = new Map<string, PageResource>();
@@ -279,6 +280,10 @@ export class PageResourceLoader extends Common.ObjectWrapper.ObjectWrapper<Event
     } finally {
       pageResource.duration = performance.now() - startTime;
       this.releaseLoadSlot(initiator.target);
+      if (!this.#reportedStartupResourcesLoaded && this.#currentlyLoading === 0) {
+        Host.rnPerfMetrics.startupDeveloperResourcesLoadingFinished(this.getNumberOfResources().resources);
+        this.#reportedStartupResourcesLoaded = true;
+      }
       this.dispatchEventToListeners(Events.UPDATE);
     }
   }
@@ -354,6 +359,7 @@ export class PageResourceLoader extends Common.ObjectWrapper.ObjectWrapper<Event
     }
     Host.rnPerfMetrics.developerResourceLoadingFinished(
         parsedURL, Host.UserMetrics.DeveloperResourceLoaded.FALLBACK_AFTER_FAILURE, result);
+
     return result;
   }