Mojo: add generation of stubs and struct serialization

BUG=None
TEST=Will be added after all generated files are done
R=darin@chromium.org, darin

Review URL: https://codereview.chromium.org/54303006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232230 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 232230
Expose WebGL extension WEBGL_debug_renderer_info to Google domains
through a chromium finch experiment.

We would launch with 5% first for data collection purpose.

Blink side CL: https://codereview.chromium.org/51323003/

BUG=309831
TEST=
R=asvitkine@chromium.org, bajones@chromium.org, jln@chromium.org, kbr@chromium.org, thestig@chromium.org

Review URL: https://codereview.chromium.org/48113021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232231 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 232231