Reset shader in ovals GM 

Not resetting the shader for the paints produces interesting 
results on the following configs...

Review URL: https://codereview.chromium.org/13947042/


git-svn-id: http://skia.googlecode.com/svn/trunk@8740 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/ovals.cpp b/gm/ovals.cpp
index d0c2165..b5a12e7 100755
--- a/gm/ovals.cpp
+++ b/gm/ovals.cpp
@@ -265,6 +265,9 @@
 
             canvas->drawRect(oval, rectPaint);
             canvas->drawOval(oval, fPaints[i]);
+
+            fPaints[i].setShader(NULL);
+
             canvas->restore();
         }
     }