Change uses of base::JoinString to pass StringPieces where possible.

chrome/browser/chromeos/power/peripheral_battery_observer.cc

 // Copyright (c) 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/chromeos/power/peripheral_battery_observer.h"
 
 #include <vector>
 
 #include "ash/shell.h"
 #include "ash/strings/grit/ash_strings.h"
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
+#include "base/strings/string_piece.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/notifications/notification.h"
 #include "chrome/browser/notifications/notification_ui_manager.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/grit/theme_resources.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 33 matching lines @@
 }
 
 std::string ExtractBluetoothAddress(const std::string& path) {
   int header_size = strlen(kHIDBatteryPathPrefix);
   int end_size = strlen(kHIDBatteryPathSuffix);
   int key_len = path.size() - header_size - end_size;
   if (key_len <= 0)
     return std::string();
   std::string reverse_address =
       base::ToLowerASCII(path.substr(header_size, key_len));
-  std::vector<std::string> result = base::SplitString(
+  std::vector<base::StringPiece> result = base::SplitStringPiece(
       reverse_address, ":", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
   std::reverse(result.begin(), result.end());
   std::string address = base::JoinString(result, ":");
   return address;
 }
 
 class PeripheralBatteryNotificationDelegate : public NotificationDelegate {
  public:
   explicit PeripheralBatteryNotificationDelegate(const std::string& id)
       : id_(id) {}
@@ skipping 151 matching lines @@
 
 void PeripheralBatteryObserver::CancelNotification(const std::string& address) {
   // If last_used_profile_ is NULL then no notification has been posted yet.
   if (notification_profile_) {
     g_browser_process->notification_ui_manager()->CancelById(
         address, NotificationUIManager::GetProfileID(notification_profile_));
   }
 }
 
 }  // namespace chromeos