PDF : New factory function for SkPDFDevice

src/pdf/SkPDFCanon.h

Index: src/pdf/SkPDFCanon.h
diff --git a/src/pdf/SkPDFCanon.h b/src/pdf/SkPDFCanon.h
index 6a677e9a68920d8038aef6eb9564fb3dc71955f3..7c5cdf70c1ece5ef39e3cabd71dd663b1368ea57 100644
--- a/src/pdf/SkPDFCanon.h
+++ b/src/pdf/SkPDFCanon.h
@@ -73,6 +73,15 @@ public:
     void addBitmap(SkPDFBitmap*);
     void removeBitmap(SkPDFBitmap*);
 
+    void assertEmpty() const {
+        SkASSERT(fFontRecords.isEmpty());
+        SkASSERT(fFunctionShaderRecords.isEmpty());
+        SkASSERT(fAlphaShaderRecords.isEmpty());
+        SkASSERT(fImageShaderRecords.isEmpty());
+        SkASSERT(fGraphicStateRecords.isEmpty());
+        SkASSERT(fBitmapRecords.isEmpty());
+    }
+
 private:
     struct FontRec {
         SkPDFFont* fFont;