GitLab

Move D&D client stuff into client namespace.
Provide some convenient getters/setters.

BUG=none
TEST=existing automation
TBR=sky
Review URL: http://codereview.chromium.org/8949010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@114595 0039d316-1c4b-4281-b951-d872f2087c98