Merging from Master

Author: ramanpreetSinghKhinda

firebase-perf/src/main/java/com/google/firebase/perf/FirebasePerfRegistrar.java

@@ -51,12 +51,14 @@ public List<Component<?>> getComponents() {
             .add(Dependency.required(FirebaseInstallationsApi.class))
             .add(Dependency.requiredProvider(TransportFactory.class))
             .factory(FirebasePerfRegistrar::providesFirebasePerformance)
-            // Since the SDK is eager(auto starts at app start), we use "lazy" dependency for some
-            // components that are not required during initialization so as not to force initialize
-            // them at app startup (refer
-            // https://github.com/google/guice/wiki/InjectingProviders#providers-for-lazy-loading).
-            .eagerInDefaultApp()
             .build(),
+        /**
+         * Fireperf SDK is lazily by {@link FirebasePerformanceInitializer} during {@link
+         * com.google.firebase.perf.application.AppStateMonitor#onActivityResumed(Activity)}. we use
+         * "lazy" dependency for some components that are not required during initialization so as
+         * not to force initialize them at app startup (refer
+         * https://github.com/google/guice/wiki/InjectingProviders#providers-for-lazy-loading)*
+         */
         LibraryVersionComponent.create("fire-perf", BuildConfig.VERSION_NAME));
   }
 

firebase-perf/src/main/java/com/google/firebase/perf/FirebasePerformance.java

@@ -180,15 +180,15 @@ public static FirebasePerformance getInstance() {
     TransportManager.getInstance()
         .initialize(firebaseApp, firebaseInstallationsApi, transportFactoryProvider);
 
-    Context context = firebaseApp.getApplicationContext();
+    Context appContext = firebaseApp.getApplicationContext();
     // TODO(b/110178816): Explore moving off of main thread.
-    mMetadataBundle = extractMetadata(context);
+    mMetadataBundle = extractMetadata(appContext);
 
     remoteConfigManager.setFirebaseRemoteConfigProvider(firebaseRemoteConfigProvider);
     this.configResolver = configResolver;
     this.configResolver.setMetadataBundle(mMetadataBundle);
-    this.configResolver.setApplicationContext(context);
-    gaugeManager.setApplicationContext(context);
+    this.configResolver.setApplicationContext(appContext);
+    gaugeManager.setApplicationContext(appContext);
 
     mPerformanceCollectionForceEnabledState = configResolver.getIsPerformanceCollectionEnabled();
   }
@@ -439,16 +439,16 @@ public HttpMetric newHttpMetric(@NonNull URL url, @NonNull @HttpMethod String ht
   /**
    * Extracts the metadata bundle from the ApplicationContext.
    *
-   * @param context The ApplicationContext.
+   * @param appContext The ApplicationContext.
    * @return A shallow copy of the bundle containing the metadata extracted from the context.
    */
-  private static ImmutableBundle extractMetadata(Context context) {
+  private static ImmutableBundle extractMetadata(Context appContext) {
     Bundle bundle = null;
     try {
       ApplicationInfo ai =
-          context
+          appContext
               .getPackageManager()
-              .getApplicationInfo(context.getPackageName(), PackageManager.GET_META_DATA);
+              .getApplicationInfo(appContext.getPackageName(), PackageManager.GET_META_DATA);
 
       bundle = ai.metaData;
     } catch (NameNotFoundException | NullPointerException e) {

firebase-perf/src/main/java/com/google/firebase/perf/FirebasePerformanceInitializer.java

@@ -0,0 +1,31 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.firebase.perf;
+
+import com.google.firebase.perf.application.AppStateMonitor;
+
+/**
+ * FirebasePerformanceInitializer to initialize FirebasePerformance during app cold start
+ *
+ * @hide
+ */
+public final class FirebasePerformanceInitializer implements AppStateMonitor.AppColdStartCallback {
+
+  @Override
+  public void onAppColdStart() {
+    // Initialize FirebasePerformance when app cold starts.
+    FirebasePerformance.getInstance();
+  }
+}