Hide MHTMLGenerationManager from chrome.

BUG=98716
Review URL: https://chromiumcodereview.appspot.com/9566001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@124430 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/content/public/browser/web_contents.h b/content/public/browser/web_contents.h
index 46e139e..655ec2e 100644
--- a/content/public/browser/web_contents.h
+++ b/content/public/browser/web_contents.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include "base/basictypes.h"
+#include "base/callback_forward.h"
 #include "base/process_util.h"
 #include "base/string16.h"
 #include "content/common/content_export.h"
@@ -269,6 +270,12 @@
                         const FilePath& dir_path,
                         SavePageType save_type) = 0;
 
+  // Generate an MHTML representation of the current page in the given file.
+  virtual void GenerateMHTML(
+      const FilePath& file,
+      const base::Callback<void(const FilePath& /* path to the MHTML file */,
+                                int64 /* size of the file */)>& callback) = 0;
+
   // Returns true if the active NavigationEntry's page_id equals page_id.
   virtual bool IsActiveEntry(int32 page_id) = 0;