Disabling failing unit test on linux

TBR=reed
TEST=unit test CanvasTest
BUG=http://code.google.com/p/skia/issues/detail?id=507



git-svn-id: http://skia.googlecode.com/svn/trunk@3229 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed