PDF: Canon now owns a reference to all interned objects

src/pdf/SkPDFFont.h

Index: src/pdf/SkPDFFont.h
diff --git a/src/pdf/SkPDFFont.h b/src/pdf/SkPDFFont.h
index 6ff4c7b15ea7de77f5e80cb042f1e5a8573d217e..c286fa481a50e70e5d54ec062e40f6f253694714 100644
--- a/src/pdf/SkPDFFont.h
+++ b/src/pdf/SkPDFFont.h
@@ -150,11 +150,8 @@ public:
                          uint16_t searchGlyphID);
 
 protected:
-    SkPDFCanon* const fCanon;
-
     // Common constructor to handle common members.
-    SkPDFFont(SkPDFCanon* canon,
-              const SkAdvancedTypefaceMetrics* fontInfo,
+    SkPDFFont(const SkAdvancedTypefaceMetrics* fontInfo,
               SkTypeface* typeface,
               SkPDFDict* relatedFontDescriptor);