Add git rolling instructions directly to depot_tools.

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 55 matching lines @@
 :: (parens) are necessary, otherwise batch puts an extra space after 32.
 reg Query "HKLM\Hardware\Description\System\CentralProcessor\0" | %FIND_EXE% /i "x86" > NUL && (set OS_BITS=32) || (set OS_BITS=64)
 
 if not exist "%WIN_TOOLS_ROOT_DIR%\.git_bleeding_edge" (
   set GIT_VERSION=2.7.4
 ) else (
   set GIT_VERSION=2.7.4
 )
 set GIT_VERSION=%GIT_VERSION%-%OS_BITS%
 
-set GIT_FETCH_URL=https://commondatastorage.googleapis.com/chrome-infra/PortableGit-%GIT_VERSION%-bit.7z.exe
+set GIT_FETCH_URL=https://storage.googleapis.com/chrome-infra/PortableGit-%GIT_VERSION%-bit.7z.exe
 set GIT_DOWNLOAD_PATH=%ZIP_DIR%\git.7z.exe
 set GIT_BIN_DIR=git-%GIT_VERSION%_bin
 set GIT_INST_DIR=%WIN_TOOLS_ROOT_DIR%\%GIT_BIN_DIR%
 set GIT_EXE_PATH=%GIT_INST_DIR%\bin\git.exe
 
 :: Clean up any release which doesn't match the one we want.
 for /d %%i in ("%WIN_TOOLS_ROOT_DIR%\git-*_bin") do (
   if not "%%i" == "%WIN_TOOLS_ROOT_DIR%\git-%GIT_VERSION%_bin" (
     echo Cleaning old git installation %%i
     rmdir /s /q "%%i"
@@ skipping 113 matching lines @@
 goto :END
 
 
 :returncode
 set WIN_TOOLS_ROOT_URL=
 set WIN_TOOLS_ROOT_DIR=
 exit /b %ERRORLEVEL%
 
 :END
 call :returncode %ERRORLEVEL%