Update uses of UTF conversions in content/ to use the base:: namespace.

content/browser/renderer_host/render_widget_host_view_mac.mm

 // 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 "content/browser/renderer_host/render_widget_host_view_mac.h"
 
 #import <objc/runtime.h>
 #include <QuartzCore/QuartzCore.h>
 
 #include "base/basictypes.h"
@@ skipping 1052 matching lines @@
     selected_text_.clear();
   } else {
     size_t pos = range.GetMin() - offset;
     size_t n = range.length();
 
     DCHECK(pos + n <= text.length()) << "The text can not fully cover range.";
     if (pos >= text.length()) {
       DCHECK(false) << "The text can not cover range.";
       return;
     }
-    selected_text_ = UTF16ToUTF8(text.substr(pos, n));
+    selected_text_ = base::UTF16ToUTF8(text.substr(pos, n));
   }
 
   [cocoa_view_ setSelectedRange:range.ToNSRange()];
   // Updates markedRange when there is no marked text so that retrieving
   // markedRange immediately after calling setMarkdText: returns the current
   // caret position.
   if (![cocoa_view_ hasMarkedText]) {
     [cocoa_view_ setMarkedRange:range.ToNSRange()];
   }
 
@@ skipping 2899 matching lines @@
   return YES;
 }
 
 - (BOOL)isOpaque {
   if (renderWidgetHostView_->use_core_animation_)
     return YES;
   return [super isOpaque];
 }
 
 @end