Store more info about shortcuts, part 1.

This splits the pieces of Shortcut that tracked info about an AutocompleteMatch
into a separate MatchCore struct, which makes it easier to construct Shortcuts
in the various different ways we need, as well as making it simpler to
add/remove future data.

This doesn't actually store any relevant info in the shortcuts database yet, so
there is very little user effect (just during a single run of Chrome).

BUG=304441
TEST=none
R=bartn@chromium.org, brettw@chromium.org

Review URL: https://codereview.chromium.org/26099002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227576 0039d316-1c4b-4281-b951-d872f2087c98
Add a content switch to turn off unprefixed MediaSource API

this is for ICS devices

blink CL: https://codereview.chromium.org/26028003/

BUG=304112

Review URL: https://codereview.chromium.org/26015004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227577 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 227577