Expose browser login through a private ext

prototype only

BUG=293733
R=courage@chromium.org, kalman@chromium.org

Review URL: https://codereview.chromium.org/24156004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225197 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225197
Disable BrowserPluginHostTest.AcceptDragEvents under ASan on Mac

BUG=297576
TBR=sadrul@chromium.org

Review URL: https://codereview.chromium.org/23534072

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225198 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225198