Switch rules to share a single .rules / .mk file for msvs because the limitations of configurations prevent the possibility of a rules being different between configurations.
Switch rules to share a single .rules / .mk file for msvs because the
limitations of configurations prevent the possibility of a rules being
different between configurations.

BUG=None
TEST=None
TBR=sgk

Review URL: http://codereview.chromium.org/341061
witwall/gyp,witwall/gyp,witwall/gyp,witwall/gyp,witwall/gyp