Add asADash entry point into SkPathEffect to allow extracting Dash info from PathEffects

include/effects/SkDashPathEffect.h

Index: include/effects/SkDashPathEffect.h
diff --git a/include/effects/SkDashPathEffect.h b/include/effects/SkDashPathEffect.h
index 41f8f5a43e4bf703f242cc62118251f4a25a03ef..f69e90586a378b3c004e1565323970eb0f78d94b 100644
--- a/include/effects/SkDashPathEffect.h
+++ b/include/effects/SkDashPathEffect.h
@@ -49,6 +49,8 @@ public:
                           const SkStrokeRec&, const SkMatrix&,
                           const SkRect*) const SK_OVERRIDE;
 
+    virtual DashType asADash(DashInfo* info) const SK_OVERRIDE;
+
     virtual Factory getFactory() const SK_OVERRIDE;
 
     static SkFlattenable* CreateProc(SkReadBuffer&);
@@ -63,8 +65,11 @@ public:
     SkDashPathEffect(const SkScalar intervals[], int count, SkScalar phase);
 
 private:
+    void setInternalMembers(SkScalar phase);
+
     SkScalar*   fIntervals;
     int32_t     fCount;
+    SkScalar    fPhase;
     // computed from phase
     SkScalar    fInitialDashLength;
     int32_t     fInitialDashIndex;