Bug 1373984 - Turn nsIDocument::mCharacterSet into mozilla::NotNull<const mozilla::Encoding*>. r=hsivonen

MozReview-Commit-ID: GF0YXDwfA14

parser/htmlparser/nsScanner.h

@@ -36,7 +36,9 @@ private:
   void operator=(const nsReadEndCondition& aOther); // No assigning
 };
 
-class nsScanner {
+class nsScanner final {
+      using Encoding = mozilla::Encoding;
+      template <typename T> using NotNull = mozilla::NotNull<T>;
   public:
 
       /**
@@ -142,7 +144,8 @@ class nsScanner {
        *  @param   aCharsetSource- where the charset info came from
        *  @return  
        */
-      nsresult SetDocumentCharset(const nsACString& aCharset, int32_t aSource);
+      nsresult SetDocumentCharset(NotNull<const Encoding*> aEncoding,
+                                  int32_t aSource);
 
       void BindSubstring(nsScannerSubstring& aSubstring, const nsScannerIterator& aStart, const nsScannerIterator& aEnd);
       void CurrentPosition(nsScannerIterator& aPosition);