The common file prevents duplication of the same @font-face definitions,
and allows additional font weights and character sets added by one
project to be automatically available for all other Roboto users.

This CL also updates the Roboto font files from Google Fonts and removes
the .woff file, since Chrome has complete support for woff2.

BUG=439114
TEST=Locally tested chrome://md-settings, chrome://proximity-auth and a
  PDF file on desktop, and chrome://contextual-search-promo/promo.html
  on Android.

Review URL: https://codereview.chromium.org/1142893002

Cr-Commit-Position: refs/heads/master@{#330689}