[Cronet] Hook up library loader, system proxy and network change notifier to async api.

components/cronet/android/cronet_url_request_context.cc

 // Copyright 2014 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.
 
 #include "components/cronet/android/cronet_url_request_context.h"
 
 #include <string>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
@@ skipping 88 matching lines @@
   context_adapter->StopNetLog();
 }
 
 static jint SetMinLogLevel(JNIEnv* env, jobject jcaller, jint jlog_level) {
   jint old_log_level = static_cast<jint>(logging::GetMinLogLevel());
   // MinLogLevel is global, shared by all URLRequestContexts.
   logging::SetMinLogLevel(static_cast<int>(jlog_level));
   return old_log_level;
 }
 
+// Called on application's main Java thread.
+static void InitRequestContextOnMainThread(JNIEnv* env,
+                                           jobject jcaller,
+                                           jlong jurl_request_context_adapter) {
+  if (jurl_request_context_adapter == 0)
+    return;
+  CronetURLRequestContextAdapter* context_adapter =
+      reinterpret_cast<CronetURLRequestContextAdapter*>(
+          jurl_request_context_adapter);
+  context_adapter->InitRequestContextOnMainThread();
+}
+
 }  // namespace cronet