path ops -- fix skp bugs

This fixes a series of bugs discovered by running
the small set of Skia skp files through pathops
to flatten the clips.
Review URL: https://codereview.chromium.org/14798004

git-svn-id: http://skia.googlecode.com/svn/trunk@9042 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/pathops/SkPathWriter.h b/src/pathops/SkPathWriter.h
index f90a580..5747082 100644
--- a/src/pathops/SkPathWriter.h
+++ b/src/pathops/SkPathWriter.h
@@ -20,6 +20,7 @@
     bool hasMove() const;
     void init();
     bool isClosed() const;
+    bool isEmpty() const { return fEmpty; }
     void lineTo();
     const SkPath* nativePath() const;
     void nudge();