Valgrind: Widen suppressions for P2PSocketHost.

BUG=308683
NOTRY=true
R=groby@chromium.org
TBR=groby

Review URL: https://codereview.chromium.org/29303003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229465 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229465