Avoids releasing capture prematurily when dragging tabs from one to another browser window

BUG=338297

Review URL: https://codereview.chromium.org/180983002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255826 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 255826
UMA Histograms for Register Promos

Add UMA histograms for register promos.

BUG=350228

Review URL: https://codereview.chromium.org/189623004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255827 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 255827