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

components/cronet/android/java/src/org/chromium/net/impl/CronetLibraryLoader.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.impl;
 
 import android.content.Context;
 import android.os.Handler;
 import android.os.Looper;
 
@@ skipping 23 matching lines @@
      * any thread, the load and initialization is performed on main thread.
      */
     public static void ensureInitialized(
             final Context context, final CronetEngine.Builder builder) {
         synchronized (sLoadLock) {
             if (sInitStarted) {
                 return;
             }
             sInitStarted = true;
             ContextUtils.initApplicationContext(context.getApplicationContext());
-            builder.loadLibrary();
+            if (builder.libraryLoader() != null) {
+                builder.libraryLoader().loadLibrary(builder.libraryName());

[kapishnikov, 2016/06/02 16:33:38]

If the client passes the custom library loader but the Java implementation is
loaded from dynamite, calling the custom loader may not work. The custom class
loader has no way to access dynamite. I guess, we should somehow prohibit the
custom loader if the code is loaded from dynamite.

[pauljensen, 2016/07/22 14:18:04]

Ya, we'll probably want to @hide CronetEngine.setLibraryLoader()

[pauljensen, 2016/07/22 14:18:42]

I should mention I added this to my TODO list for integration.

+            } else {
+                System.loadLibrary(builder.libraryName());
+            }
             ContextUtils.initApplicationContextForNative();
             if (!ImplVersion.CRONET_VERSION.equals(nativeGetCronetVersion())) {
                 throw new RuntimeException(String.format("Expected Cronet version number %s, "
                                 + "actual version number %s.",
                         ImplVersion.CRONET_VERSION, nativeGetCronetVersion()));
             }
             Log.i(TAG, "Cronet version: %s, arch: %s", ImplVersion.CRONET_VERSION,
                     System.getProperty("os.arch"));
             // Init native Chromium CronetEngine on Main UI thread.
             Runnable task = new Runnable() {
@@ skipping 36 matching lines @@
         // the undesired initial network change observer notification, which
         // will cause active requests to fail with ERR_NETWORK_CHANGED.
         nativeCronetInitOnMainThread();
         sMainThreadInitDone = true;
     }
 
     // Native methods are implemented in cronet_library_loader.cc.
     private static native void nativeCronetInitOnMainThread();
     private static native String nativeGetCronetVersion();
 }