wstring: convert all SetPageTitle APIs to use string16

chrome/browser/tab_contents/tab_contents_view_mac.mm

 // Copyright (c) 2011 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.
 
 #import <Carbon/Carbon.h>
 
 #include "chrome/browser/tab_contents/tab_contents_view_mac.h"
 
 #include <string>
 
@@ skipping 156 matching lines @@
 }
 
 void TabContentsViewMac::RenderViewCreated(RenderViewHost* host) {
   // We want updates whenever the intrinsic width of the webpage changes.
   // Put the RenderView into that mode. The preferred width is used for example
   // when the "zoom" button in the browser window is clicked.
   host->Send(new ViewMsg_EnablePreferredSizeChangedMode(
       host->routing_id(), kPreferredSizeWidth));
 }
 
-void TabContentsViewMac::SetPageTitle(const std::wstring& title) {
+void TabContentsViewMac::SetPageTitle(const string16& title) {
   // Meaningless on the Mac; widgets don't have a "title" attribute
 }
 
 void TabContentsViewMac::OnTabCrashed(base::TerminationStatus /* status */,
                                       int /* error_code */) {
   if (!sad_tab_.get()) {
     DCHECK(tab_contents_);
     if (tab_contents_) {
       SadTabController* sad_tab =
           [[SadTabController alloc] initWithTabContents:tab_contents_
@@ skipping 385 matching lines @@
       [[[notification userInfo] objectForKey:kSelectionDirection]
         unsignedIntegerValue];
   if (direction == NSDirectSelection)
     return;
 
   [self tabContents]->
       FocusThroughTabTraversal(direction == NSSelectingPrevious);
 }
 
 @end