Add lock to SkPDFDict

src/pdf/SkPDFStream.h

Index: src/pdf/SkPDFStream.h
diff --git a/src/pdf/SkPDFStream.h b/src/pdf/SkPDFStream.h
index 6371bc187d14d9c90ed463d7734cfa67776f4d2e..636ea984e39efd04b8132922d02e7238fa14be6d 100644
--- a/src/pdf/SkPDFStream.h
+++ b/src/pdf/SkPDFStream.h
@@ -35,10 +35,7 @@ public:
     explicit SkPDFStream(SkData* data);
     /** Deprecated constructor. */
     explicit SkPDFStream(SkStream* stream);
-    /** Create a PDF stream with the same content and dictionary entries
-     *  as the passed one.
-     */
-    explicit SkPDFStream(const SkPDFStream& pdfStream);
+
     virtual ~SkPDFStream();
 
     // The SkPDFObject interface.
@@ -54,6 +51,11 @@ protected:
         kCompressed_State,     //!< The stream's already been compressed.
     };
 
+    /** Create a PDF stream with the same content and dictionary entries
+     *  as the passed one.
+     */
+    explicit SkPDFStream(const SkPDFStream& pdfStream);
+
     /* Create a PDF stream with no data.  The setData method must be called to
      * set the data.
      */