Fix for ovals failing on Xoom.

The fallback path for ellipses when we don't have GLSL derivative
instructions was only setting one attribute in the effect stage, but
we use two attributes.

R=robertphillips@google.com

Review URL: https://codereview.chromium.org/23514047

git-svn-id: http://skia.googlecode.com/svn/trunk/src@11184 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/GrOvalRenderer.cpp b/gpu/GrOvalRenderer.cpp
index 667efc4..946cdc0 100644
--- a/gpu/GrOvalRenderer.cpp
+++ b/gpu/GrOvalRenderer.cpp
@@ -691,7 +691,8 @@
                                                     innerXRadius > 0 && innerYRadius > 0);
 
     static const int kEllipseCenterAttrIndex = 1;
-    drawState->addCoverageEffect(effect, kEllipseCenterAttrIndex)->unref();
+    static const int kEllipseEdgeAttrIndex = 2;
+    drawState->addCoverageEffect(effect, kEllipseCenterAttrIndex, kEllipseEdgeAttrIndex)->unref();
 
     // Compute the reciprocals of the radii here to save time in the shader
     SkScalar xRadRecip = SkScalarInvert(xRadius);