Add getClipStack method to lua SkCanvas

R=reed@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/177933003

git-svn-id: http://skia.googlecode.com/svn/trunk@13567 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/utils/SkLua.h b/include/utils/SkLua.h
index c609746..f67502a 100644
--- a/include/utils/SkLua.h
+++ b/include/utils/SkLua.h
@@ -15,6 +15,7 @@
 struct lua_State;
 
 class SkCanvas;
+class SkClipStack;
 class SkMatrix;
 class SkPaint;
 class SkPath;
@@ -53,6 +54,7 @@
     void pushPaint(const SkPaint&, const char tableKey[] = NULL);
     void pushPath(const SkPath&, const char tableKey[] = NULL);
     void pushCanvas(SkCanvas*, const char tableKey[] = NULL);
+    void pushClipStack(const SkClipStack&, const char tableKey[] = NULL);
 
 private:
     lua_State*  fL;