Dependancy check for .proto files is added.

proto_checker is added and checkdeps is modified so that import lines in proto files are checked for matching with rules stated in DEPS file.

BUG=684383
R=brettw@chromium.org

Patch from Ramin Halavati <rhalavati@chromium.org>.

Review-Url: https://codereview.chromium.org/2653023004 .
3 files changed