Fixups for clipstack, convexity test for paths.

Review URL http://codereview.appspot.com/4250056/

git-svn-id: http://skia.googlecode.com/svn/trunk@891 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/include/GrDrawTarget.h b/gpu/include/GrDrawTarget.h
index 576bd7a..285665b 100644
--- a/gpu/include/GrDrawTarget.h
+++ b/gpu/include/GrDrawTarget.h
@@ -106,6 +106,9 @@
 
     /**
      * Sets the stencil settings to use for the next draw.
+     * Changing the clip has the side-effect of possibly zeroing
+     * out the client settable stencil bits. So multipass algorithms
+     * using stencil should not change the clip between passes.
      * @param settings  the stencil settings to use.
      */
     void setStencil(const GrStencilSettings& settings) {
@@ -156,6 +159,8 @@
      * Sets the current clip to the region specified by clip. All draws will be
      * clipped against this clip if kClip_StateBit is enabled.
      *
+     * Setting the clip may (or may not) zero out the client's stencil bits.
+     *
      * @param description of the clipping region
      */
     void setClip(const GrClip& clip);
@@ -965,6 +970,8 @@
                                        vertexIndex * vertexSize);
     }
 
+    static void VertexLayoutUnitTest();
+
 protected:
 
     // Helpers for GrDrawTarget subclasses that won't have private access to
@@ -1047,9 +1054,6 @@
         AutoGeometrySrcRestore(const AutoGeometrySrcRestore&);
         AutoGeometrySrcRestore& operator =(AutoGeometrySrcRestore&);
     };
-
-private:
-    void VertexLayoutUnitTest();
 };
 
 #endif