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 a1c548265367cd0b0eac1d963070799ac6652b5d..01c7dc4c6856f9278fc2398e7ef702de6c87d070 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&);
@@ -64,8 +66,11 @@ public:
                      bool scaleToFit = false);
 
 private:
+    void setInternalMembers(SkScalar phase);
+
     SkScalar*   fIntervals;
     int32_t     fCount;
+    SkScalar    fPhase;
     // computed from phase
     SkScalar    fInitialDashLength;
     int32_t     fInitialDashIndex;