Mojo: Convert HandleWatcher to use the C++ mojo::Handle.

R=darin@chromium.org, sky@chromium.org

Review URL: https://codereview.chromium.org/85453006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237152 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 237152
Remove cc_unittest lsan suppression

This patch removes suppression from cc_unittest for a leak that was fixed.

NOTRY=True
BUG=317966

Review URL: https://codereview.chromium.org/86243002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237153 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 237153