Update data reduction proxy statistics prefs less often on desktop

components/data_reduction_proxy/browser/data_reduction_proxy_metrics.cc

 // Copyright 2014 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 "components/data_reduction_proxy/browser/data_reduction_proxy_metrics.h"
 
 #include "base/metrics/histogram.h"
-#include "base/prefs/pref_service.h"
-#include "base/prefs/scoped_user_pref_update.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
+#include "components/data_reduction_proxy/browser/data_reduction_proxy_delayed_pref_service.h"
 #include "components/data_reduction_proxy/browser/data_reduction_proxy_settings.h"
 #include "components/data_reduction_proxy/common/data_reduction_proxy_headers.h"
 #include "components/data_reduction_proxy/common/data_reduction_proxy_pref_names.h"
 #include "net/base/host_port_pair.h"
 #include "net/http/http_response_headers.h"
 #include "net/proxy/proxy_retry_info.h"
 #include "net/proxy/proxy_service.h"
 #include "net/url_request/url_request_context.h"
 
 namespace data_reduction_proxy {
@@ skipping 165 matching lines @@
   DCHECK_EQ(length, list->GetSize());
 }
 
 // DailyContentLengthUpdate maintains a data saving pref. The pref is a list
 // of |kNumDaysInHistory| elements of daily total content lengths for the past
 // |kNumDaysInHistory| days.
 class DailyContentLengthUpdate {
  public:
   DailyContentLengthUpdate(
       const char* pref,
-      PrefService* pref_service)
-      : update_(pref_service, pref) {
+      DataReductionProxyDelayedPrefService* pref_service)
+      : update_(pref_service->GetList(pref)) {
   }
 
   void UpdateForDataChange(int days_since_last_update) {
     // New empty lists may have been created. Maintain the invariant that
     // there should be exactly |kNumDaysInHistory| days in the histories.
-    MaintainContentLengthPrefsWindow(update_.Get(), kNumDaysInHistory);
+    MaintainContentLengthPrefsWindow(update_, kNumDaysInHistory);
     if (days_since_last_update) {
       MaintainContentLengthPrefForDateChange(days_since_last_update);
     }
   }
 
   // Update the lengths for the current day.
   void Add(int content_length) {
-    AddInt64ToListPref(kNumDaysInHistory - 1, content_length, update_.Get());
+    AddInt64ToListPref(kNumDaysInHistory - 1, content_length, update_);
   }
 
   int64 GetListPrefValue(size_t index) {
     return ListPrefInt64Value(*update_, index);
   }
 
  private:
   // Update the list for date change and ensure the list has exactly |length|
   // elements. The last entry in the list will be for the current day after
   // the update.
@@ skipping 18 matching lines @@
     // lists longer than kNumDaysInHistory. The additional items will be cut off
     // from the head of the lists by |MaintainContentLengthPrefsWindow|, below.
     for (int i = 0;
          i < days_since_last_update && i < static_cast<int>(kNumDaysInHistory);
          ++i) {
       update_->AppendString(base::Int64ToString(0));
     }
 
     // Entries for new days may have been appended. Maintain the invariant that
     // there should be exactly |kNumDaysInHistory| days in the histories.
-    MaintainContentLengthPrefsWindow(update_.Get(), kNumDaysInHistory);
+    MaintainContentLengthPrefsWindow(update_, kNumDaysInHistory);
   }
 
-  ListPrefUpdate update_;
+  base::ListValue* update_;
 };
 
 // DailyDataSavingUpdate maintains a pair of data saving prefs, original_update_
 // and received_update_. pref_original is a list of |kNumDaysInHistory| elements
 // of daily total original content lengths for the past |kNumDaysInHistory|
 // days. pref_received is the corresponding list of the daily total received
 // content lengths.
 class DailyDataSavingUpdate {
  public:
   DailyDataSavingUpdate(
       const char* pref_original,
       const char* pref_received,
-      PrefService* pref_service)
+      DataReductionProxyDelayedPrefService* pref_service)
       : original_(pref_original, pref_service),
         received_(pref_received, pref_service) {
   }
 
   void UpdateForDataChange(int days_since_last_update) {
     original_.UpdateForDataChange(days_since_last_update);
     received_.UpdateForDataChange(days_since_last_update);
   }
 
   // Update the lengths for the current day.
@@ skipping 54 matching lines @@
     return received_content_length;
   }
   return original_content_length;
 }
 
 void UpdateContentLengthPrefsForDataReductionProxy(
     int received_content_length,
     int original_content_length,
     bool with_data_reduction_proxy_enabled,
     DataReductionProxyRequestType request_type,
-    base::Time now, PrefService* prefs) {
+    base::Time now,
+    DataReductionProxyDelayedPrefService* prefs) {
   // TODO(bengr): Remove this check once the underlying cause of
   // http://crbug.com/287821 is fixed. For now, only continue if the current
   // year is reported as being between 1972 and 2970.
   base::TimeDelta time_since_unix_epoch = now - base::Time::UnixEpoch();
   const int kMinDaysSinceUnixEpoch = 365 * 2;  // 2 years.
   const int kMaxDaysSinceUnixEpoch = 365 * 1000;  // 1000 years.
   if (time_since_unix_epoch.InDays() < kMinDaysSinceUnixEpoch ||
       time_since_unix_epoch.InDays() > kMaxDaysSinceUnixEpoch) {
     return;
   }
@@ skipping 118 matching lines @@
           unknown.GetListPrefValue(kNumDaysInHistory - 2));
     }
   }
 }
 
 void UpdateContentLengthPrefs(
     int received_content_length,
     int original_content_length,
     bool with_data_reduction_proxy_enabled,
     DataReductionProxyRequestType request_type,
-    PrefService* prefs) {
+    DataReductionProxyDelayedPrefService* prefs) {
   int64 total_received = prefs->GetInt64(
       data_reduction_proxy::prefs::kHttpReceivedContentLength);
   int64 total_original = prefs->GetInt64(
       data_reduction_proxy::prefs::kHttpOriginalContentLength);
   total_received += received_content_length;
   total_original += original_content_length;
   prefs->SetInt64(data_reduction_proxy::prefs::kHttpReceivedContentLength,
                   total_received);
   prefs->SetInt64(data_reduction_proxy::prefs::kHttpOriginalContentLength,
                   total_original);
 
   UpdateContentLengthPrefsForDataReductionProxy(
       received_content_length,
       original_content_length,
       with_data_reduction_proxy_enabled,
       request_type,
       base::Time::Now(),
       prefs);
 }
 
 }  // namespace data_reduction_proxy