Steps to reproduce the problem:
Try to build any older version chrome (M45 - M48)
It fails with below error:
Error:
________ running '/usr/bin/python src/third_party/mojo/src/mojo/public/tools/download_shell_binary.py --tools-directory=../../../../../../tools' in '/root/ishant/chromium'
Traceback (most recent call last):
  File "src/third_party/mojo/src/mojo/public/tools/download_shell_binary.py", line 101, in <module>
    sys.exit(main())
  File "src/third_party/mojo/src/mojo/public/tools/download_shell_binary.py", line 98, in main
    return download(args.tools_directory, args.version_file)
  File "src/third_party/mojo/src/mojo/public/tools/download_shell_binary.py", line 49, in download
    download_version_for_platform(version, platform, tools_directory)
  File "src/third_party/mojo/src/mojo/public/tools/download_shell_binary.py", line 67, in download_version_for_platform
    depot_tools_path)
  File "/root/ishant/chromium/src/third_party/mojo/src/mojo/public/tools/pylib/gs.py", line 31, in download_from_public_bucket
    env=env)
  File "/usr/lib/python2.7/subprocess.py", line 566, in check_output
    process = Popen(stdout=PIPE, *popenargs, **kwargs)
  File "/usr/lib/python2.7/subprocess.py", line 710, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1335, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory
Error: Command '/usr/bin/python src/third_party/mojo/src/mojo/public/tools/download_shell_binary.py --tools-directory=../../../../../../tools' returned non-zero exit status 1 in /root/ishant/chromium

What is the expected behavior?
Build should pass

What went wrong?
Build Failed because third_party/gsutil removed in depot_tools w.r.t
https://chromium.googlesource.com/chromium/tools/depot_tools.git/+/8ea74908a6b6f9ec1ab1a8333d40b54cef0f6f19

it has hard coded path referring to third_part/gsutil @ https://chromium.googlesource.com/chromium/src/+/8c522ea0f84229c2dba86756bc7c9923610b439f/third_party/mojo/src/mojo/public/tools/pylib/gs.py

Did this work before? Yes Before https://codereview.chromium.org/2280023003

Chrome version: 45.0.2454.104  Channel: stable
OS Version: All
Flash Version: 

Build Failed because third_party/gsutil removed in depot_tools w.r.t
https://chromium.googlesource.com/chromium/tools/depot_tools.git/+/8ea74908a6b6f9ec1ab1a8333d40b54cef0f6f19

it has hard coded path referring to third_part/gsutil @ https://chromium.googlesource.com/chromium/src/+/8c522ea0f84229c2dba86756bc7c9923610b439f/third_party/mojo/src/mojo/public/tools/pylib/gs.py