Switch depot_tools python to 2.7.4.

bootstrap/win/win_tools.bat

 @echo off
 :: 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.
 
 :: This script will try to find if svn and python are accessible and it not,
 :: it will try to download it and 'install' it in depot_tools.
 
 :: Sadly, we can't use SETLOCAL here otherwise it ERRORLEVEL is not correctly
 :: returned.
@@ skipping 108 matching lines @@
 if errorlevel 1 goto :PYTHON_INSTALL
 
 :: We are done.
 set ERRORLEVEL=0
 goto :END
 
 
 :PYTHON_INSTALL
 echo Installing python ...
 :: Cleanup python directory if it was existing.
-if exist "%WIN_TOOLS_ROOT_DIR%\python_bin\." rd /q /s "%WIN_TOOLS_ROOT_DIR%\python_bin"
-call svn co -q %WIN_TOOLS_ROOT_URL%/third_party/python_26 "%WIN_TOOLS_ROOT_DIR%\python_bin"
+if exist "%WIN_TOOLS_ROOT_DIR%\python_274\." rd /q /s "%WIN_TOOLS_ROOT_DIR%\python_274"
+call svn co -q %WIN_TOOLS_ROOT_URL%/third_party/python_274 "%WIN_TOOLS_ROOT_DIR%\python_274"
 if errorlevel 1 goto :PYTHON_FAIL
 :: Create the batch files.
 call copy /y "%~dp0python.new.bat" "%WIN_TOOLS_ROOT_DIR%\python.bat" 1>nul
 call copy /y "%~dp0pylint.new.bat" "%WIN_TOOLS_ROOT_DIR%\pylint.bat" 1>nul
 set ERRORLEVEL=0
 goto :END
 
 
 :PYTHON_FAIL
 echo ... Failed to checkout python automatically.
-echo Please visit http://python.org to download the latest python 2.x client before
+echo Please visit http://python.org to download the latest python 2.7.x client before
 echo continuing.
 echo You can also get the "prebacked" version used at %WIN_TOOLS_ROOT_URL%/third_party/
 set ERRORLEVEL=1
 goto :END
 
 
 :returncode
 set WIN_TOOLS_ROOT_URL=
 set WIN_TOOLS_ROOT_DIR=
 exit /b %ERRORLEVEL%
 
 :END
 call :returncode %ERRORLEVEL%