in pure HTML into the extension-based web apps used internally
by Chrome.

BUG=49233
TEST=unit_tests --gtest_filter=ExtensionFromWebApp.*

Review URL: http://codereview.chromium.org/4139008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@64845 0039d316-1c4b-4281-b951-d872f2087c98