Add explicit base namespace to string16 users.

chrome/common/print_messages.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/common/print_messages.h"
 
 #include "base/basictypes.h"
 #include "base/strings/string16.h"
 #include "ui/gfx/size.h"
 
@@ skipping 35 matching lines @@
   desired_dpi = 0;
   document_cookie = 0;
   selection_only = false;
   supports_alpha_blend = false;
   preview_ui_id = -1;
   preview_request_id = 0;
   is_first_request = false;
   print_scaling_option = blink::WebPrintScalingOptionSourceSize;
   print_to_pdf = false;
   display_header_footer = false;
-  title = string16();
-  url = string16();
+  title = base::string16();
+  url = base::string16();
   should_print_backgrounds = false;
 }
 
 PrintMsg_PrintPages_Params::PrintMsg_PrintPages_Params()
   : pages() {
 }
 
 PrintMsg_PrintPages_Params::~PrintMsg_PrintPages_Params() {}
 
 void PrintMsg_PrintPages_Params::Reset() {
   params.Reset();
   pages = std::vector<int>();
 }
 
 PrintHostMsg_RequestPrintPreview_Params::
     PrintHostMsg_RequestPrintPreview_Params()
     : is_modifiable(false),
       webnode_only(false),
       has_selection(false),
       selection_only(false) {
 }
 
 PrintHostMsg_RequestPrintPreview_Params::
     ~PrintHostMsg_RequestPrintPreview_Params() {}