Normalize the way we include grit/ generated files

Both Chromium and Crosswalk code mostly include directly "grit/" without
the module prefix, so normalize on that practice. This matters so that
the grit rules in the DEPS file will consistently be verified.
Add module specific grit/ rules to DEPS files

The DEPS' include_rules section is used by tools/check-xwalk-deps to
ensure that we are not including files from unexpected parts of the
code.

Adding the dependency to the resource ensure in the tests ensure that
the right path will be added to the include_dir.
Merge pull request #1440 from cmarcelo/normalize-grit-includes

Normalize the way we include generated files inside "grit/"