Clean up long-press affordance handler

Cleaned up long-press affordance handler to only work with gesture
events (rather than using both touch and gesture events). Now,
affordance is shown on tap-down and dismissed on tap or tap-cancel.

BUG=306201

Review URL: https://codereview.chromium.org/76683002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236439 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236439
Add wez@ to OWNERs of cast channel code.

Review URL: https://codereview.chromium.org/77733009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236441 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236441
Add jorgelo as a Linux sandbox OWNER

R=jln@chromium.org
TBR=jln@chromium.org

Review URL: https://codereview.chromium.org/77733010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236442 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236442