linux: add UMA stat for the file system where the prefs are stored

chrome/browser/pref_service.cc

 // Copyright (c) 2010 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/pref_service.h"
 
 #include <algorithm>
 #include <string>
 
 #include "app/l10n_util.h"
 #include "base/command_line.h"
 #include "base/file_path.h"
+#include "base/file_util.h"
 #include "base/histogram.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/stl_util-inl.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
 #include "base/utf_string_conversions.h"
 #include "build/build_config.h"
 #include "chrome/browser/chrome_thread.h"
@@ skipping 50 matching lines @@
   Source<PrefService> source(pref);
   NotificationService::current()->Notify(NotificationType::PROFILE_ERROR,
                                          source, Details<int>(&message_id));
 }
 
 }  // namespace
 
 // static
 PrefService* PrefService::CreatePrefService(const FilePath& pref_filename,
                                             Profile* profile) {
+#if defined(OS_LINUX)
+  // We'd like to see what fraction of our users have the preferences
+  // stored on a network file system, as we've had no end of troubles
+  // with NFS/AFS.
+  // TODO(evanm): remove this once we've collected state.
+  file_util::FileSystemType fstype;
+  if (file_util::GetFileSystemType(pref_filename.DirName(), &fstype)) {
+    UMA_HISTOGRAM_ENUMERATION("PrefService.FileSystemType",
+                              static_cast<int>(fstype),
+                              file_util::FILE_SYSTEM_TYPE_COUNT);
+  }
+#endif
+
   return new PrefService(
       PrefValueStore::CreatePrefValueStore(pref_filename, profile, false));
 }
 
 // static
 PrefService* PrefService::CreateUserPrefService(const FilePath& pref_filename) {
   return new PrefService(
       PrefValueStore::CreatePrefValueStore(pref_filename, NULL, true));
 }
 
@@ skipping 621 matching lines @@
   return pref_value_store_->PrefValueFromExtensionStore(name_.c_str());
 }
 
 bool PrefService::Preference::IsUserControlled() const {
   return pref_value_store_->PrefValueFromUserStore(name_.c_str());
 }
 
 bool PrefService::Preference::IsUserModifiable() const {
   return pref_value_store_->PrefValueUserModifiable(name_.c_str());
 }