Ensure that inactive tab images line up correctly with frame image when themed.  Also fix HasCustomImage so that it only returns true when the image is in the extension's original set, not just a generated theme for the cache.
Ensure that inactive tab images line up correctly with frame image when themed.  Also fix HasCustomImage so that it only returns true when the image is in the extension's original set, not just a generated theme for the cache.

BUG= http://crbug.com/21134
TEST= install a theme with a detailed frame background.  Open many tabs.  Make sure the inactive tab image lines up with the frame image.

Review URL: http://codereview.chromium.org/193030

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@25829 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser