Reapply and refactor of: "Media Galleries API Metadata: Image metadata"
Original patch:
https://codereview.chromium.org/
191583002
This takes the original patch and changes libexif from a load-time 'shared_library' to a runtime-loaded 'loadable_module'. This is based on rsesek's reasoning that it would reduce overall performance impact as well as not require a sandbox hole for Mac 10.6.
TBR=
BUG=318450
Review URL: https://codereview.chromium.org/
226643007
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@263427 0039d316-1c4b-4281-b951-d872f2087c98