[Cronet] Call System.loadLibrary() from impl not API

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.IntDef;
 import android.support.annotation.Nullable;
@@ skipping 222 matching lines @@
          * @param libName the name of the native library backing Cronet.
          * @return the builder to facilitate chaining.
          * @hide only used by internal implementation.
          */
         public Builder setLibraryName(String libName) {
             mLibraryName = libName;
             return this;
         }
 
         /**
+         * @hide only used by internal implementation.
+         */
+        public String libraryName() {
+            return mLibraryName;
+        }
+
+        /**
          * Sets a {@link LibraryLoader} to be used to load the native library.
          * 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) {
             mLibraryLoader = loader;
             return this;
         }
 
         /**
          * @hide only used by internal implementation.
          */
-        public void loadLibrary() {
-            if (mLibraryLoader == null) {
-                System.loadLibrary(mLibraryName);
-            } else {
-                mLibraryLoader.loadLibrary(mLibraryName);
-            }
+        public LibraryLoader libraryLoader() {
+            return mLibraryLoader;
         }
 
         /**
          * 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) {
@@ skipping 898 matching lines @@
      * @hide as it's a prototype.
      */
     public interface RequestFinishedListener { // TODO(klm): Add a convenience abstract class.
         /**
          * Invoked with request info.
          * @param requestInfo {@link UrlRequestInfo} for finished request.
          */
         void onRequestFinished(UrlRequestInfo requestInfo);
     }
 }