Implement A/B experiment for anti-DDoS.

net/url_request/url_request_throttler_manager.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 "net/url_request/url_request_throttler_manager.h"
 
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
@@ skipping 71 matching lines @@
 }
 
 void URLRequestThrottlerManager::AddToOptOutList(const std::string& host) {
   // There is an edge case here that we are not handling, to keep things
   // simple.  If a host starts adding the opt-out header to its responses
   // after there are already one or more entries in url_entries_ for that
   // host, the pre-existing entries may still perform back-off throttling.
   // In practice, this would almost never occur.
   if (opt_out_hosts_.find(host) == opt_out_hosts_.end()) {
     UMA_HISTOGRAM_COUNTS("Throttling.SiteOptedOut", 1);
-    if (base::FieldTrialList::TrialExists("ThrottlingEnabled")) {
+    if (base::FieldTrialList::TrialExists("HttpThrottlingEnabled")) {
       UMA_HISTOGRAM_COUNTS(base::FieldTrial::MakeName(
-          "Throttling.SiteOptedOut", "ThrottlingEnabled"), 1);
+          "Throttling.SiteOptedOut", "HttpThrottlingEnabled"), 1);
     }
 
     net_log_->EndEvent(
         NetLog::TYPE_THROTTLING_DISABLED_FOR_HOST,
         make_scoped_refptr(new NetLogStringParameter("host", host)));
     opt_out_hosts_.insert(host);
   }
 }
 
 void URLRequestThrottlerManager::OverrideEntryForTests(
@@ skipping 137 matching lines @@
 void URLRequestThrottlerManager::OnNetworkChange() {
   // Remove all entries.  Any entries that in-flight requests have a reference
   // to will live until those requests end, and these entries may be
   // inconsistent with new entries for the same URLs, but since what we
   // want is a clean slate for the new connection state, this is OK.
   url_entries_.clear();
   requests_since_last_gc_ = 0;
 }
 
 }  // namespace net