Net: Convert username and password to string16.

net/http/http_auth_handler_mock.h

Index: net/http/http_auth_handler_mock.h
===================================================================
--- net/http/http_auth_handler_mock.h	(revision 53997)
+++ net/http/http_auth_handler_mock.h	(working copy)
@@ -8,6 +8,7 @@
 
 #include <string>
 
+#include "base/string16.h"
 #include "base/task.h"
 #include "net/http/http_auth_handler.h"
 #include "net/http/http_auth_handler_factory.h"
@@ -69,8 +70,8 @@
  protected:
   virtual bool Init(HttpAuth::ChallengeTokenizer* challenge);
 
-  virtual int GenerateAuthTokenImpl(const std::wstring* username,
-                                    const std::wstring* password,
+  virtual int GenerateAuthTokenImpl(const string16* username,
+                                    const string16* password,
                                     const HttpRequestInfo* request,
                                     CompletionCallback* callback,
                                     std::string* auth_token);