Offline Pages: Use 'binary encoding' to create MHTML, instead of base64.

content/public/browser/web_contents.h

Index: content/public/browser/web_contents.h
diff --git a/content/public/browser/web_contents.h b/content/public/browser/web_contents.h
index eb0da0053015e6628ce668f844482e4f5700d8b4..86bac275b1702d683cd292ed3cb434be350f00c3 100644
--- a/content/public/browser/web_contents.h
+++ b/content/public/browser/web_contents.h
@@ -540,8 +540,13 @@ class WebContents : public PageNavigator,
                                     const std::string& headers) = 0;
 
   // Generate an MHTML representation of the current page in the given file.
+  // If |use_binary_encoding| is specified, a Content-Transfer-Encoding value of
+  // 'binary' will be used, instead of a combination of 'quoted-printable' and
+  // 'base64'.  Binary encoding is known to have interoperability issues and is
+  // not the recommended encoding for shareable content.
   virtual void GenerateMHTML(
       const base::FilePath& file,
+      bool use_binary_encoding,
       const base::Callback<void(int64_t /* size of the file */)>& callback) = 0;
 
   // Returns the contents MIME type after a navigation.