SkPDF: add canon assert before adding code that might break it

src/pdf/SkPDFDevice.h

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkPDFDevice_DEFINED
@@ skipping 162 matching lines @@
         return fInitialTransform;
     }
 
     /** Returns a SkPDFGlyphSetMap which represents glyph usage of every font
      *  that shows on this device.
      */
     const SkPDFGlyphSetMap& getFontGlyphUsage() const {
         return *(fFontGlyphUsage.get());
     }
 
+#ifdef SK_DEBUG
+    SkPDFCanon* getCanon() const { return fCanon; }
+#endif  // SK_DEBUG
+
 protected:
     const SkBitmap& onAccessBitmap() SK_OVERRIDE {
         return fLegacyBitmap;
     }
 
     SkSurface* newSurface(const SkImageInfo&, const SkSurfaceProps&) SK_OVERRIDE;
 
 private:
     // TODO(vandebo): push most of SkPDFDevice's state into a core object in
     // order to get the right access levels without using friend.
@@ skipping 115 matching lines @@
 
     typedef SkBaseDevice INHERITED;
 
     // TODO(edisonn): Only SkDocument_PDF and SkPDFImageShader should be able to create
     // an SkPDFDevice
     //friend class SkDocument_PDF;
     //friend class SkPDFImageShader;
 };
 
 #endif