Makes core mojo binding js files explicitly define their name

It's rather tricky to infer the name when executing via WebFrame. So,
rather than attempting that I'm explicitly defining the module
name.

This also changes the binding generator to include the path too.

BUG=none
TEST=none
R=abarth@chromium.org

Review URL: https://codereview.chromium.org/183893015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@254765 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 254765