Cleaned up duplication in browser tests.

Also changed the peerconnection server port from 8888 to 7778 
in these tests: 8888 tends to collide with for instance locally run hexa servers, which is really annoying.

R=tommi@chromium.org
BUG=

Review URL: https://codereview.chromium.org/24578002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226711 0039d316-1c4b-4281-b951-d872f2087c98
Only throttle TouchMove events in the renderer

Currently, the renderer throttles any TouchEvent type if there is a pending
commit.  However, this throttling should really be limited to streamed event
types.  Restrict the throttled TouchEvent type to TouchMove, eliminating
unnecessary latency between a touch stream and the potential followup gesture
stream.

BUG=303165

Review URL: https://codereview.chromium.org/25745002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226712 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226711
SVN changes up to revision 226712