First pass at automated vs2013 toolchain script

d:\src>python cr\src\tools\win\toolchain\toolchain2013.py
...
d:\src>d:\src\win_toolchain_2013\env
...
d:\src>cd cr\src
d:\src\cr\src>gclient runhooks
...
d:\src\cr\src>ninja -C out\Debug chrome

Can also pass --express to toolchain2013.py for Express toolchain.

BUG=309197
R=zturner@chromium.org

Review URL: https://codereview.chromium.org/66263002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@234244 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 234244