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

components/cronet/android/cronet_url_request_adapter.cc

Index: components/cronet/android/cronet_url_request_adapter.cc
diff --git a/components/cronet/android/cronet_url_request_adapter.cc b/components/cronet/android/cronet_url_request_adapter.cc
index 265895af4512a5ab4f932c5d8e4d9a1942f6799e..14e54c76ee69534b01c6b824ff6391914b570408 100644
--- a/components/cronet/android/cronet_url_request_adapter.cc
+++ b/components/cronet/android/cronet_url_request_adapter.cc
@@ -41,15 +41,15 @@ void CronetURLRequestAdapter::AddRequestHeader(const std::string& name,
   initial_request_headers_.SetHeader(name, value);
 }
 
-bool CronetURLRequestAdapter::PostTaskToNetworkThread(
+void CronetURLRequestAdapter::PostTaskToNetworkThread(
     const tracked_objects::Location& from_here,
     const base::Closure& task) {
   DCHECK(!IsOnNetworkThread());
-  return context_->GetNetworkTaskRunner()->PostTask(from_here, task);
+  context_->PostTaskToNetworkThread(from_here, task);
 }
 
 bool CronetURLRequestAdapter::IsOnNetworkThread() const {
-  return context_->GetNetworkTaskRunner()->BelongsToCurrentThread();
+  return context_->IsOnNetworkThread();
 }
 
 void CronetURLRequestAdapter::Start() {