Use path intersection instead of saveLayer+mesh to mask projected ripples

bug:14297149

SaveLayer's performance cost is high, and proportional to the surface
being projected onto. Since ripples (even unbounded ones) are now
always projected to the arbitrary background content behind them, this
cost is especially important to avoid.

This removes the last semi-secret, saveLayer from the projected
ripple implementation.

Also fixes the HW test app to correctly demonstrate this projection
masking behavior.

Additionaly, alters PathTessellator to gracefully handle
counter-clockwise paths, and simplifies the work done by
ShadowTessellator to ensure all of its paths are counterclockwise.

Change-Id: Ibe9e12812bd10a774e20b1d444a140c368cbba8c
diff --git a/libs/hwui/PathTessellator.h b/libs/hwui/PathTessellator.h
index 8ac9a3b..ccae65b 100644
--- a/libs/hwui/PathTessellator.h
+++ b/libs/hwui/PathTessellator.h
@@ -82,7 +82,7 @@
             const mat4& transform, VertexBuffer& vertexBuffer);
 
     /**
-     * Approximates a convex, CW outline into a Vector of 2d vertices.
+     * Approximates a convex outline into a clockwise Vector of 2d vertices.
      *
      * @param path The outline to be approximated
      * @param thresholdSquared The threshold of acceptable error (in pixels) when approximating