Optimize writes upon ProfileManager::UpdateLastUser.

chrome/browser/profiles/profile_info_cache.cc

 // Copyright (c) 2012 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/profiles/profile_info_cache.h"
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/i18n/case_conversion.h"
 #include "base/logging.h"
@@ skipping 453 matching lines @@
   std::string icon_url;
   GetInfoForProfileAtIndex(index)->GetString(kAvatarIconKey, &icon_url);
   size_t icon_index = 0;
   if (!profiles::IsDefaultAvatarIconUrl(icon_url, &icon_index))
     DLOG(WARNING) << "Unknown avatar icon: " << icon_url;
 
   return icon_index;
 }
 
 void ProfileInfoCache::SetProfileActiveTimeAtIndex(size_t index) {
+  if (base::Time::Now() - GetProfileActiveTimeAtIndex(index) <
+      base::TimeDelta::FromHours(1)) {
+    return;
+  }
+
   scoped_ptr<base::DictionaryValue> info(
       GetInfoForProfileAtIndex(index)->DeepCopy());
   info->SetDouble(kActiveTimeKey, base::Time::Now().ToDoubleT());
   // This takes ownership of |info|.
   SetInfoForProfileAtIndex(index, info.release());
 }
 
 void ProfileInfoCache::SetNameOfProfileAtIndex(size_t index,
                                                const base::string16& name) {
   scoped_ptr<base::DictionaryValue> info(
@@ skipping 690 matching lines @@
   std::vector<base::FilePath>::const_iterator it;
   for (it = profiles_to_rename.begin(); it != profiles_to_rename.end(); ++it) {
     size_t profile_index = GetIndexOfProfileWithPath(*it);
     SetProfileIsUsingDefaultNameAtIndex(profile_index, true);
     // This will assign a new "Person %d" type name and re-sort the cache.
     SetNameOfProfileAtIndex(profile_index, ChooseNameForNewProfile(
         GetAvatarIconIndexOfProfileAtIndex(profile_index)));
   }
 #endif
 }