Anti-DDoS enhancements: Log to net log, UMA stats, improved policy.

chrome/service/cloud_print/cloud_print_url_fetcher.cc

 // Copyright (c) 2011 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 "chrome/service/cloud_print/cloud_print_url_fetcher.h"
 
 #include "base/stringprintf.h"
 #include "base/values.h"
 #include "chrome/common/net/http_return.h"
 #include "chrome/service/cloud_print/cloud_print_consts.h"
@@ skipping 84 matching lines @@
         action = delegate_->HandleJSONData(source,
                                            url,
                                            response_dict,
                                            succeeded);
       else
         action = RETRY_REQUEST;
     }
   }
   // Retry the request if needed.
   if (action == RETRY_REQUEST) {
-    // If the response code is greater than or equal to 500, then the back-off
-    // period has been increased at the network level; otherwise, explicitly
-    // call ReceivedContentWasMalformed() to count the current request as a
-    // failure and increase the back-off period.
-    if (response_code < 500)
-      request_->ReceivedContentWasMalformed();
+    // Explicitly call ReceivedContentWasMalformed() to ensure the current
+    // request gets counted as a failure for calculation of the back-off
+    // period.  If it was already a failure by status code, this call will
+    // be ignored.
+    request_->ReceivedContentWasMalformed();
 
     ++num_retries_;
     if ((-1 != source->max_retries()) &&
         (num_retries_ > source->max_retries())) {
       // Retry limit reached. Give up.
       delegate_->OnRequestGiveUp();
     } else {
       // Either no retry limit specified or retry limit has not yet been
       // reached. Try again. Set up the request headers again because the token
       // may have changed.
@@ skipping 49 matching lines @@
 
 net::URLRequestContextGetter* CloudPrintURLFetcher::GetRequestContextGetter() {
   ServiceURLRequestContextGetter* getter =
       g_service_process->GetServiceURLRequestContextGetter();
   // Now set up the user agent for cloudprint.
   std::string user_agent = getter->user_agent();
   base::StringAppendF(&user_agent, " %s", kCloudPrintUserAgent);
   getter->set_user_agent(user_agent);
   return getter;
 }