[Cronet] Add new API methods before removing old ones

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

Index: components/cronet/android/api/src/org/chromium/net/CronetEngine.java
diff --git a/components/cronet/android/api/src/org/chromium/net/CronetEngine.java b/components/cronet/android/api/src/org/chromium/net/CronetEngine.java
index 35c2a26c099c02adb393240324807f2fb2e659b9..e386b670818795ac45ad4087aafae7d93410e0ff 100644
--- a/components/cronet/android/api/src/org/chromium/net/CronetEngine.java
+++ b/components/cronet/android/api/src/org/chromium/net/CronetEngine.java
@@ -1154,4 +1154,20 @@ public abstract class CronetEngine {
      * @hide it's a prototype.
      */
     public abstract void removeRequestFinishedListener(RequestFinishedInfo.Listener listener);
+
+    /**
+     * Creates a builder for {@link UrlRequest}. All callbacks formatted
+     * generated {@link UrlRequest} objects will be invoked on
+     * {@code executor}'s threads. {@code executor} must not run tasks on the
+     * 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 UrlRequest.Builder newUrlRequestBuilder(
+            String url, UrlRequest.Callback callback, Executor executor) {
+        return new UrlRequest.Builder(url, callback, executor, this);
+    }
 }