Assign color=0 in GrDrawState.cpp to stop tools from raising false alarms about uninit reads.

We were assigning color to oldColor but it in turn would never be read because the valid flags
would be cleared.

R=jvanverth@google.com
Review URL: https://codereview.chromium.org/12313150

git-svn-id: http://skia.googlecode.com/svn/trunk@7886 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed