Merged revision(s) 1532627 from tomcat/trunk:
Prevent default mouse event on Canvas element to prevent browsers from marking text (and Chrome from displaying the "text" cursor).

git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc7.0.x/trunk@1532628 13f79535-47bb-0310-9956-ffa450edef68