[Chromecast] Add connectivity checking for Chromecast.

chromecast/net/connectivity_checker.h

+// 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.
+
+#ifndef CHROMECAST_NET_CONNECTIVITY_CHECKER_H_
+#define CHROMECAST_NET_CONNECTIVITY_CHECKER_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "net/base/network_change_notifier.h"
+#include "net/url_request/url_request.h"
+
+class GURL;
+
+namespace base {
+class MessageLoopProxy;
+}
+
+namespace net {
+class URLRequestContext;
+}
+
+namespace chromecast {
+
+// Simple class to check network connectivity by sending a HEAD http request
+// to given url.
+class ConnectivityChecker
+    : public base::RefCountedThreadSafe<ConnectivityChecker>,
+      public net::URLRequest::Delegate,
+      public net::NetworkChangeNotifier::ConnectionTypeObserver {
+ public:
+  class ConnectivityObserver {
+   public:
+    // Will be called when internet connectivity changes
+    virtual void OnConnectivityChanged(bool connected) = 0;
+
+   protected:
+    ConnectivityObserver() {}
+    virtual ~ConnectivityObserver() {};

[byungchul, 2015/02/20 01:32:39]

';' not necessary.

And, as far as I know, 'virtual' is not necessary though many pure classes has
that. Can you check if chromium complaints if it is not a virtual dtor?

[derekjchow1, 2015/02/20 02:24:17]

Done.

I removed the virtual keyword for the dtor in this instance and cast_shell built
fine. That being said, the style guide says that pure virtual classes should
have a virtual destructor.

+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(ConnectivityObserver);
+  };
+
+  explicit ConnectivityChecker(
+      const scoped_refptr<base::MessageLoopProxy>& loop_proxy);
+
+  void AddConnectivityObserver(ConnectivityObserver* observer);
+  void RemoveConnectivityObserver(ConnectivityObserver* observer);
+
+  // Returns if there is internet connectivity
+  bool Connected() const;
+
+  // Checks for connectivity
+  void Check();
+
+ protected:
+  // Empty constructor for test

[gunsch, 2015/02/20 01:56:03]

alternately, make it private and add a protected

static ConnectivityChecker* CreateConnectivityCheckerForTesting()

Chromium has checks that enforce methods ending in "ForTesting" are only called
in test contexts

[derekjchow1, 2015/02/20 02:24:16]

This actually isn't referenced now. Removed.

+  ConnectivityChecker();
+  ~ConnectivityChecker() override;
+
+ private:
+  friend class base::RefCountedThreadSafe<ConnectivityChecker>;
+
+  // UrlRequest::Delegate implementation:
+  void OnResponseStarted(net::URLRequest* request) override;
+  void OnReadCompleted(net::URLRequest* request, int bytes_read) override;
+
+  // Initializes ConnectivityChecker
+  void Initialize();
+
+  // NetworkChangeNotifier::ConnectionTypeObserver implementation:
+  void OnConnectionTypeChanged(
+      net::NetworkChangeNotifier::ConnectionType type) override;
+
+  // Cancels current connectivity checking in progress.
+  void Cancel();
+
+  // Sets connectivity and alerts observers if it has changed
+  void SetConnectivity(bool connected);
+
+  scoped_ptr<GURL> connectivity_check_url_;
+  scoped_ptr<net::URLRequestContext> url_request_context_;
+  scoped_ptr<net::URLRequest> url_request_;
+  const scoped_refptr<ObserverListThreadSafe<ConnectivityObserver> >
+      connectivity_observer_list_;
+  const scoped_refptr<base::MessageLoopProxy> loop_proxy_;
+  bool connected_;
+  unsigned int bad_responses_;
+
+  DISALLOW_COPY_AND_ASSIGN(ConnectivityChecker);
+};
+
+}  // namespace chromecast
+
+#endif  // CHROMECAST_NET_CONNECTIVITY_CHECKER_H_