remove fClipStack and attach/deattach-from-canvas

src/pdf/SkPDFDevice.h

Index: src/pdf/SkPDFDevice.h
diff --git a/src/pdf/SkPDFDevice.h b/src/pdf/SkPDFDevice.h
index f8497c63ff8a0ff4db3c861ae033ffac0770ebdc..6a167d979ac9e2869cfcf09d58d87192a04ba042 100644
--- a/src/pdf/SkPDFDevice.h
+++ b/src/pdf/SkPDFDevice.h
@@ -119,8 +119,6 @@ public:
     void drawDevice(const SkDraw&, SkBaseDevice*, int x, int y,
                     const SkPaint&) override;
 
-    void onAttachToCanvas(SkCanvas* canvas) override;
-    void onDetachFromCanvas() override;
     SkImageInfo imageInfo() const override;
 
     // PDF specific methods.
@@ -256,8 +254,6 @@ private:
     };
     SkSinglyLinkedList<ContentEntry> fContentEntries;
 
-    const SkClipStack* fClipStack;
-
     SkScalar fRasterDpi;
 
     SkPDFDocument* fDocument;