Remove ThumbnailDatabase::history_publisher_.

Partial landing of https://chromiumcodereview.appspot.com/23512002/ .
Turns out that one does not simply remove IChromeHistoryIndexer, but
this ThumbnailDatabase code really is dead.

BUG=161116,294306

Review URL: https://codereview.chromium.org/23609065

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225397 0039d316-1c4b-4281-b951-d872f2087c98
Fix a threading bug in the brlapi basec braille controller

This CL enables brlapi support by default in builds for chromeos (it's already enabled by default in chromeos itself, so that part is a noop). This revealed a threading bug in the implementation which is also fixed my moving a file_path_watcher from the IO thread to the FILE threadd.

BUG=178559

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=225008

Review URL: https://codereview.chromium.org/24325002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225398 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225398