Convert TimeFormat (chrome/common/time_format.*) to string16 (from wstring).

chrome/common/time_format.h

-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// 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.
 
 #ifndef CHROME_COMMON_TIME_FORMAT_H__
 #define CHROME_COMMON_TIME_FORMAT_H__
 #pragma once
 
 // This file defines methods to format time values as strings.
 
-#include <string>
+#include "base/string16.h"
 
 #include "unicode/smpdtfmt.h"
 
 namespace base {
 class Time;
 class TimeDelta;
 }
 
 class TimeFormat {
  public:
   // TimeElapsed, TimeRemaining and TimeRemainingShort functions:
   // These functions return a localized string of approximate time duration. The
   // conditions are simpler than PastTime since these functions are used for
   // in-progress operations and users have different expectations of units.
 
   // Returns times in elapsed-format: "3 mins ago", "2 days ago".
-  static std::wstring TimeElapsed(const base::TimeDelta& delta);
+  static string16 TimeElapsed(const base::TimeDelta& delta);
 
   // Returns times in remaining-format: "3 mins left", "2 days left".
-  static std::wstring TimeRemaining(const base::TimeDelta& delta);
+  static string16 TimeRemaining(const base::TimeDelta& delta);
 
   // Returns times in short-format: "3 mins", "2 days".
-  static std::wstring TimeRemainingShort(const base::TimeDelta& delta);
+  static string16 TimeRemainingShort(const base::TimeDelta& delta);
 
   // For displaying a relative time in the past.  This method returns either
   // "Today", "Yesterday", or an empty string if it's older than that.
   //
   // TODO(brettw): This should be able to handle days in the future like
   //    "Tomorrow".
   // TODO(tc): This should be able to do things like "Last week".  This
   //    requires handling singluar/plural for all languages.
   //
   // The second parameter is optional, it is midnight of "Now" for relative day
   // computations: Time::Now().LocalMidnight()
   // If NULL, the current day's midnight will be retrieved, which can be
   // slow. If many items are being processed, it is best to get the current
   // time once at the beginning and pass it for each computation.
-  static std::wstring RelativeDate(const base::Time& time,
-                                   const base::Time* optional_midnight_today);
+  static string16 RelativeDate(const base::Time& time,
+                               const base::Time* optional_midnight_today);
 };
 
 #endif  // CHROME_COMMON_TIME_FORMAT_H__