Fix == operator in GrTextureDomain so we don't compair uninitilized values

We were getting random behavior when comparing two GrTexureDomains since
fDomain was not initialized when the mode was set to ignore.

BUG=skia:
R=bsalomon@google.com

Author: egdaniel@google.com

Review URL: https://codereview.chromium.org/469393007
1 file changed