Introduce ERR_NETWORK_CHANGED and allow URLFetcher to automatically retry on that error.

net/url_request/url_fetcher_core.h

Index: net/url_request/url_fetcher_core.h
diff --git a/net/url_request/url_fetcher_core.h b/net/url_request/url_fetcher_core.h
index 4b258e5384c380e611447da09d29d79838b678d1..67589c481c2f701e077c7877a009effec04efbcf 100644
--- a/net/url_request/url_fetcher_core.h
+++ b/net/url_request/url_fetcher_core.h
@@ -20,6 +20,7 @@
 #include "base/timer.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/host_port_pair.h"
+#include "net/base/network_change_notifier.h"
 #include "net/http/http_request_headers.h"
 #include "net/url_request/url_fetcher.h"
 #include "net/url_request/url_request.h"
@@ -38,7 +39,8 @@ class URLRequestThrottlerEntryInterface;
 
 class URLFetcherCore
     : public base::RefCountedThreadSafe<URLFetcherCore>,
-      public URLRequest::Delegate {
+      public URLRequest::Delegate,
+      public NetworkChangeNotifier::ConnectionTypeObserver {
  public:
   URLFetcherCore(URLFetcher* fetcher,
                  const GURL& original_url,
@@ -86,9 +88,10 @@ class URLFetcherCore
       const URLFetcher::CreateDataCallback& create_data_callback);
   void SetStopOnRedirect(bool stop_on_redirect);
   void SetAutomaticallyRetryOn5xx(bool retry);
-  void SetMaxRetries(int max_retries);
-  int GetMaxRetries() const;
+  void SetMaxRetriesOn5xx(int max_retries);
+  int GetMaxRetriesOn5xx() const;
   base::TimeDelta GetBackoffDelay() const;
+  void SetAutomaticallyRetryOnNetworkChanges(int max_retries);
   void SaveResponseToFileAtPath(
       const FilePath& file_path,
       scoped_refptr<base::TaskRunner> file_task_runner);
@@ -122,6 +125,10 @@ class URLFetcherCore
   virtual void OnReadCompleted(URLRequest* request,
                                int bytes_read) OVERRIDE;
 
+  // Overridden from NetworkChangeNotifier::ConnectionTypeObserver:
+  virtual void OnConnectionTypeChanged(
+      NetworkChangeNotifier::ConnectionType type) OVERRIDE;
+
   URLFetcherDelegate* delegate() const { return delegate_; }
   static void CancelAll();
   static int GetNumFetcherCores();
@@ -352,11 +359,6 @@ class URLFetcherCore
       original_url_throttler_entry_;
   scoped_refptr<URLRequestThrottlerEntryInterface> url_throttler_entry_;
 
-  // |num_retries_| indicates how many times we've failed to successfully
-  // fetch this URL.  Once this value exceeds the maximum number of retries
-  // specified by the owner URLFetcher instance, we'll give up.
-  int num_retries_;
-
   // True if the URLFetcher has been cancelled.
   bool was_cancelled_;
 
@@ -384,11 +386,22 @@ class URLFetcherCore
   // re-execute the request, after the back-off delay has expired.
   // true by default.
   bool automatically_retry_on_5xx_;
-  // Maximum retries allowed.
-  int max_retries_;
+  // |num_retries_on_5xx_| indicates how many times we've failed to successfully
+  // fetch this URL due to 5xx responses.  Once this value exceeds the maximum
+  // number of retries specified by the owner URLFetcher instance,
+  // we'll give up.
+  int num_retries_on_5xx_;
+  // Maximum retries allowed when 5xx responses are received.
+  int max_retries_on_5xx_;
   // Back-off time delay. 0 by default.
   base::TimeDelta backoff_delay_;
 
+  // The number of retries that have been attempted due to ERR_NETWORK_CHANGED.
+  int num_retries_on_network_changes_;
+  // Maximum retries allowed when the request fails with ERR_NETWORK_CHANGED.
+  // 0 by default.
+  int max_retries_on_network_changes_;
+
   // Timer to poll the progress of uploading for POST and PUT requests.
   // When crbug.com/119629 is fixed, scoped_ptr is not necessary here.
   scoped_ptr<base::RepeatingTimer<URLFetcherCore> >