Allow posting the CronetEngine UI Thread initialization on a custom Ui executor instead of the defa…

components/cronet/android/api/src/org/chromium/net/CronetEngine.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.net;
 
 import android.content.Context;
 import android.net.http.HttpResponseCache;
 import android.support.annotation.VisibleForTesting;
 
@@ skipping 118 matching lines @@
          * If not set, the library will be loaded using {@link System#loadLibrary}.
          * @param loader {@code LibraryLoader} to be used to load the native library.
          * @return the builder to facilitate chaining.
          */
         public Builder setLibraryLoader(LibraryLoader loader) {
             mBuilderDelegate.setLibraryLoader(loader);
             return this;
         }
 
         /**
+         * Sets an {@link Executor} to be used for initialization code that needs to run
+         * on the Ui Thread.
+         * If not set, the library will be use the {@link android.os.Looper#getMainLooper()}.
+         * @param uiExecutor {@code Executor} to be used for the initialization.
+         * @return the builder to facilitate chaining.
+         */
+        public Builder setUiThreadExecutor(Executor uiExecutor) {
+            mBuilderDelegate.setUiThreadExecutor(uiExecutor);
+            return this;
+        }
+
+        /**
          * Sets whether <a href="https://www.chromium.org/quic">QUIC</a> protocol
          * is enabled. Defaults to disabled. If QUIC is enabled, then QUIC User Agent Id
          * containing application name and Cronet version is sent to the server.
          * @param value {@code true} to enable QUIC, {@code false} to disable.
          * @return the builder to facilitate chaining.
          */
         public Builder enableQuic(boolean value) {
             mBuilderDelegate.enableQuic(value);
             return this;
         }
@@ skipping 367 matching lines @@
      * thread calling {@link Executor#execute} to prevent blocking networking
      * operations and causing exceptions during shutdown.
      *
      * @param url URL for the generated requests.
      * @param callback callback object that gets invoked on different events.
      * @param executor {@link Executor} on which all callbacks will be invoked.
      */
     public abstract UrlRequest.Builder newUrlRequestBuilder(
             String url, UrlRequest.Callback callback, Executor executor);
 }