Data reduction proxy reconfigured on pref view

chrome/browser/net/spdyproxy/data_reduction_proxy_settings.cc

 // Copyright 2013 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/browser/net/spdyproxy/data_reduction_proxy_settings.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
@@ skipping 336 matching lines @@
   }
 
   return proxies;
 }
 
 void DataReductionProxySettings::SetDataReductionProxyEnabled(bool enabled) {
   // Prevent configuring the proxy when it is not allowed to be used.
   if (!IsDataReductionProxyAllowed())
     return;
 
-  spdy_proxy_auth_enabled_.SetValue(enabled);
-  OnProxyEnabledPrefChange();
+  if (spdy_proxy_auth_enabled_.GetValue() != enabled) {
+    spdy_proxy_auth_enabled_.SetValue(enabled);
+    OnProxyEnabledPrefChange();
+  }
 }
 
 int64 DataReductionProxySettings::GetDataReductionLastUpdateTime() {
   PrefService* local_state = GetLocalStatePrefs();
   int64 last_update_internal =
       local_state->GetInt64(prefs::kDailyHttpContentLengthLastUpdateDate);
   base::Time last_update = base::Time::FromInternalValue(last_update_internal);
   return static_cast<int64>(last_update.ToJsTime());
 }
 
@@ skipping 310 matching lines @@
 }
 
 void
 DataReductionProxySettings::ProbeWhetherDataReductionProxyIsAvailable() {
   net::URLFetcher* fetcher = GetURLFetcher();
   if (!fetcher)
     return;
   fetcher_.reset(fetcher);
   fetcher_->Start();
 }