Make URLRequestContextAdapter initialization asynchronous

components/cronet/android/url_request_context_adapter.h

 // 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.
 
 #ifndef COMPONENTS_CRONET_ANDROID_URL_REQUEST_CONTEXT_ADAPTER_H_
 #define COMPONENTS_CRONET_ANDROID_URL_REQUEST_CONTEXT_ADAPTER_H_
 
+#include <queue>
 #include <string>
 
+#include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/threading/thread.h"
 #include "net/base/net_log.h"
 #include "net/base/network_change_notifier.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_getter.h"
 
 namespace net {
 class NetLogLogger;
 }  // namespace net
 
 namespace cronet {
 
 struct URLRequestContextConfig;
+typedef base::Callback<void()> RunAfterContextInitTask;
 
 // Implementation of the Chromium NetLog observer interface.
 class NetLogObserver : public net::NetLog::ThreadSafeObserver {
  public:
   explicit NetLogObserver() {}
 
   virtual ~NetLogObserver() {}
 
   virtual void OnAddEntry(const net::NetLog::Entry& entry) OVERRIDE;
 
@@ skipping 12 matching lines @@
    protected:
     friend class base::RefCountedThreadSafe<URLRequestContextAdapterDelegate>;
 
     virtual ~URLRequestContextAdapterDelegate() {}
   };
 
   URLRequestContextAdapter(URLRequestContextAdapterDelegate* delegate,
                            std::string user_agent);
   void Initialize(scoped_ptr<URLRequestContextConfig> config);
 
+  // Runs a task that might depend on context being initialized.
+  void RunTask(const RunAfterContextInitTask& callback);

[mmenke, 2014/10/02 22:11:52]

Maybe RunTaskAfterContextInit?  It's a bit unwieldy, but makes it clearer what's
going on at callsites, where the callback's type is less obvious.  Same for the
next method.

[xunjieli, 2014/10/03 14:32:55]

Done.

+  void RunTaskOnNetworkThread(const RunAfterContextInitTask& callback);
+
   const std::string& GetUserAgent(const GURL& url) const;
 
   // net::URLRequestContextGetter implementation:
   virtual net::URLRequestContext* GetURLRequestContext() OVERRIDE;
   virtual scoped_refptr<base::SingleThreadTaskRunner> GetNetworkTaskRunner()
       const OVERRIDE;
 
   void StartNetLogToFile(const std::string& file_name);
   void StopNetLog();
 
  private:
   scoped_refptr<URLRequestContextAdapterDelegate> delegate_;
   scoped_ptr<net::URLRequestContext> context_;
   std::string user_agent_;
   base::Thread* network_thread_;
   scoped_ptr<net::NetworkChangeNotifier> network_change_notifier_;
   scoped_ptr<NetLogObserver> net_log_observer_;
   scoped_ptr<net::NetLogLogger> net_log_logger_;
 
+  // A queue of tasks that need to be run after context has been initialized.
+  std::queue<RunAfterContextInitTask> tasks_waiting_for_context_;
+  bool is_context_initialized_;
+
   virtual ~URLRequestContextAdapter();
 
   // Initializes |context_| on the Network thread.
   void InitializeURLRequestContext(scoped_ptr<URLRequestContextConfig> config);
 
   DISALLOW_COPY_AND_ASSIGN(URLRequestContextAdapter);
 };
 
 }  // namespace cronet
 
 #endif  // COMPONENTS_CRONET_ANDROID_URL_REQUEST_CONTEXT_ADAPTER_H_