ninja: Implement -Guse_deps=1 for Windows.

Let it use deps=msvc, but still use -t msvc to set up the environment.

BUG=chromium:232421
TBR=scottmg (already reviewed at https://codereview.chromium.org/15337002/)

Review URL: https://codereview.chromium.org/15464015

git-svn-id: http://gyp.googlecode.com/svn/trunk@1633 78cadc50-ecff-11dd-a971-7dbc132099af