Change LevelDBWriteOnlyTransaction to be writeable, and change its name to LevelDBDirectTransaction.

BUG=108012
R=cmumford,jsbell

Review URL: https://codereview.chromium.org/198243002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@257045 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 257045
Consolidates the two mocks for PermissionBubbleRequest.

BUG=None

Review URL: https://codereview.chromium.org/185263013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@257046 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 257046