Tweak the threshold for conic path quads computation.

We still want it to be related to the threshold for bezier generation.

b/19903239

Change-Id: Ifdce32f1c28ecea9eac98d02c73afa948341fc7d
diff --git a/libs/hwui/TessellationCache.cpp b/libs/hwui/TessellationCache.cpp
index 704a691..9df1f0d 100644
--- a/libs/hwui/TessellationCache.cpp
+++ b/libs/hwui/TessellationCache.cpp
@@ -226,9 +226,9 @@
 
     // tessellate caster outline into a 2d polygon
     Vector<Vertex> casterVertices2d;
-    const float casterRefinementThresholdSquared = 4.0f;
+    const float casterRefinementThreshold = 2.0f;
     PathTessellator::approximatePathOutlineVertices(*casterPerimeter,
-            casterRefinementThresholdSquared, casterVertices2d);
+            casterRefinementThreshold, casterVertices2d);
 
     // Shadow requires CCW for now. TODO: remove potential double-reverse
     reverseVertexArray(casterVertices2d.editArray(), casterVertices2d.size());