Make the Pepper proxy support in-process font rendering.

This implements a WebKit thread in the PPAPI plugin process so we can do the
font calls without IPC. The existing font support was refactored into
a virtual class (to prevent PPAPI from depending on WebKit and creating a
circular GYP dependency).

This moves the renderer sandbox support into content/common so that it can
be used by the PPAPI process.
Review URL: http://codereview.chromium.org/6981001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@84856 0039d316-1c4b-4281-b951-d872f2087c98
68 files changed