More v8-API-related cleanup.

R=jochen@chromium.org
BUG=324225

Review URL: https://codereview.chromium.org/107083006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242073 0039d316-1c4b-4281-b951-d872f2087c98
DevTools: Show Chrome app's background page in chrome://inspect#extension

BUG=329832

Review URL: https://codereview.chromium.org/113673003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242074 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242074