Stop setting custom user agent in demo app

PiperOrigin-RevId: 401741202

demos/main/src/main/java/com/google/android/exoplayer2/demo/DemoUtil.java

@@ -16,9 +16,7 @@
 package com.google.android.exoplayer2.demo;
 package com.google.android.exoplayer2.demo;
 
 
 import android.content.Context;
 import android.content.Context;
-import android.os.Build;
 import com.google.android.exoplayer2.DefaultRenderersFactory;
 import com.google.android.exoplayer2.DefaultRenderersFactory;
-import com.google.android.exoplayer2.ExoPlayerLibraryInfo;
 import com.google.android.exoplayer2.RenderersFactory;
 import com.google.android.exoplayer2.RenderersFactory;
 import com.google.android.exoplayer2.database.DatabaseProvider;
 import com.google.android.exoplayer2.database.DatabaseProvider;
 import com.google.android.exoplayer2.database.ExoDatabaseProvider;
 import com.google.android.exoplayer2.database.ExoDatabaseProvider;
@@ -61,13 +59,6 @@ public final class DemoUtil {
    */
    */
   private static final boolean USE_CRONET_FOR_NETWORKING = true;
   private static final boolean USE_CRONET_FOR_NETWORKING = true;
 
 
-  private static final String USER_AGENT =
-      "ExoPlayerDemo/"
-          + ExoPlayerLibraryInfo.VERSION
-          + " (Linux; Android "
-          + Build.VERSION.RELEASE
-          + ") "
-          + ExoPlayerLibraryInfo.VERSION_SLASHY;
   private static final String TAG = "DemoUtil";
   private static final String TAG = "DemoUtil";
   private static final String DOWNLOAD_ACTION_FILE = "actions";
   private static final String DOWNLOAD_ACTION_FILE = "actions";
   private static final String DOWNLOAD_TRACKER_ACTION_FILE = "tracked_actions";
   private static final String DOWNLOAD_TRACKER_ACTION_FILE = "tracked_actions";
@@ -104,9 +95,7 @@ public final class DemoUtil {
     if (httpDataSourceFactory == null) {
     if (httpDataSourceFactory == null) {
       if (USE_CRONET_FOR_NETWORKING) {
       if (USE_CRONET_FOR_NETWORKING) {
         context = context.getApplicationContext();
         context = context.getApplicationContext();
-        @Nullable
-        CronetEngine cronetEngine =
-            CronetUtil.buildCronetEngine(context, USER_AGENT, /* preferGMSCoreCronet= */ false);
+        @Nullable CronetEngine cronetEngine = CronetUtil.buildCronetEngine(context);
         if (cronetEngine != null) {
         if (cronetEngine != null) {
           httpDataSourceFactory =
           httpDataSourceFactory =
               new CronetDataSource.Factory(cronetEngine, Executors.newSingleThreadExecutor());
               new CronetDataSource.Factory(cronetEngine, Executors.newSingleThreadExecutor());
@@ -117,7 +106,7 @@ public final class DemoUtil {
         CookieManager cookieManager = new CookieManager();
         CookieManager cookieManager = new CookieManager();
         cookieManager.setCookiePolicy(CookiePolicy.ACCEPT_ORIGINAL_SERVER);
         cookieManager.setCookiePolicy(CookiePolicy.ACCEPT_ORIGINAL_SERVER);
         CookieHandler.setDefault(cookieManager);
         CookieHandler.setDefault(cookieManager);
-        httpDataSourceFactory = new DefaultHttpDataSource.Factory().setUserAgent(USER_AGENT);
+        httpDataSourceFactory = new DefaultHttpDataSource.Factory();
       }
       }
     }
     }
     return httpDataSourceFactory;
     return httpDataSourceFactory;

extensions/cronet/src/main/java/com/google/android/exoplayer2/ext/cronet/CronetUtil.java

@@ -35,9 +35,30 @@ public final class CronetUtil {
   private static final String TAG = "CronetUtil";
   private static final String TAG = "CronetUtil";
 
 
   /**
   /**
-   * Builds a {@link CronetEngine} suitable for use with ExoPlayer. When choosing a {@link
-   * CronetProvider Cronet provider} to build the {@link CronetEngine}, disabled providers are not
-   * considered. Neither are fallback providers, since it's more efficient to use {@link
+   * Builds a {@link CronetEngine} suitable for use with {@link CronetDataSource}. When choosing a
+   * {@link CronetProvider Cronet provider} to build the {@link CronetEngine}, disabled providers
+   * are not considered. Neither are fallback providers, since it's more efficient to use {@link
+   * DefaultHttpDataSource} than it is to use {@link CronetDataSource} with a fallback {@link
+   * CronetEngine}.
+   *
+   * <p>Note that it's recommended for applications to create only one instance of {@link
+   * CronetEngine}, so if your application already has an instance for performing other networking,
+   * then that instance should be used and calling this method is unnecessary. See the <a
+   * href="https://developer.android.com/guide/topics/connectivity/cronet/start">Android developer
+   * guide</a> to learn more about using Cronet for network operations.
+   *
+   * @param context A context.
+   * @return The {@link CronetEngine}, or {@code null} if no suitable engine could be built.
+   */
+  @Nullable
+  public static CronetEngine buildCronetEngine(Context context) {
+    return buildCronetEngine(context, /* userAgent= */ null, /* preferGooglePlayServices= */ false);
+  }
+
+  /**
+   * Builds a {@link CronetEngine} suitable for use with {@link CronetDataSource}. When choosing a
+   * {@link CronetProvider Cronet provider} to build the {@link CronetEngine}, disabled providers
+   * are not considered. Neither are fallback providers, since it's more efficient to use {@link
    * DefaultHttpDataSource} than it is to use {@link CronetDataSource} with a fallback {@link
    * DefaultHttpDataSource} than it is to use {@link CronetDataSource} with a fallback {@link
    * CronetEngine}.
    * CronetEngine}.
    *
    *