Remove option "-r ." from msvc target for Ninja. The latest Ninja/msvc tool does not recognize this option.
Remove option "-r ." from msvc target for Ninja.
The latest Ninja/msvc tool does not recognize this option.

I found that the latest Ninja fails to build a project generated by gyp on Window because of an unrecognized option "-r ." in *.ninja.
Ninja seems to expect only -e/-o/-h as follows.
https://github.com/martine/ninja/blob/e2709bd70462c25f0578408fdeda0d33ac42806e/src/msvc_helper_main-win32.cc#L58

Can I remove this option?
Even with this patch for gyp, I confirmed that we can build Chromium as usual, although the Ninja binary in depot_tools somehow ignores this option.

TEST=Trybots. Chromium build.
Review URL: https://codereview.chromium.org/11280207
old8xp/gyp_from_google,old8xp/gyp_from_google,old8xp/gyp_from_google,old8xp/gyp_from_google,old8xp/gyp_from_google