Update some uses of UTF conversions in chrome/browser to use the base:: namespace.

chrome/browser/ui/cocoa/omnibox/omnibox_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 "chrome/browser/ui/cocoa/omnibox/omnibox_view_mac.h"
 
 #include <Carbon/Carbon.h>  // kVK_Return
 
 #include "base/mac/foundation_util.h"
 #include "base/metrics/histogram.h"
@@ skipping 258 matching lines @@
     TextChanged();
 }
 
 void OmniboxViewMac::SetForcedQuery() {
   // We need to do this first, else |SetSelectedRange()| won't work.
   FocusLocation(true);
 
   const base::string16 current_text(GetText());
   const size_t start = current_text.find_first_not_of(base::kWhitespaceUTF16);
   if (start == base::string16::npos || (current_text[start] != '?')) {
-    SetUserText(ASCIIToUTF16("?"));
+    SetUserText(base::ASCIIToUTF16("?"));
   } else {
     NSRange range = NSMakeRange(start + 1, current_text.size() - start - 1);
     [[field_ currentEditor] setSelectedRange:range];
   }
 }
 
 bool OmniboxViewMac::IsSelectAll() const {
   if (![field_ currentEditor])
     return true;
   const NSRange all_range = NSMakeRange(0, GetTextLength());
@@ skipping 145 matching lines @@
   [paragraph_style setMaximumLineHeight:line_height];
   [paragraph_style setMinimumLineHeight:line_height];
   [paragraph_style setLineBreakMode:NSLineBreakByTruncatingTail];
   [as addAttribute:NSParagraphStyleAttributeName value:paragraph_style
              range:as_entire_string];
 
   url_parse::Component scheme, host;
   AutocompleteInput::ParseForEmphasizeComponents(
       display_text, &scheme, &host);
   bool grey_out_url = display_text.substr(scheme.begin, scheme.len) ==
-      UTF8ToUTF16(extensions::kExtensionScheme);
+      base::UTF8ToUTF16(extensions::kExtensionScheme);
   if (model()->CurrentTextIsURL() &&
       (host.is_nonempty() || grey_out_url)) {
     [as addAttribute:NSForegroundColorAttributeName value:BaseTextColor()
                range:as_entire_string];
 
     if (!grey_out_url) {
       [as addAttribute:NSForegroundColorAttributeName value:HostTextColor()
                range:ComponentToNSRange(host)];
     }
   }
@@ skipping 496 matching lines @@
 
 NSUInteger OmniboxViewMac::GetTextLength() const {
   return [field_ currentEditor] ?  [[[field_ currentEditor] string] length] :
                                    [[field_ stringValue] length];
 }
 
 bool OmniboxViewMac::IsCaretAtEnd() const {
   const NSRange selection = GetSelectedRange();
   return NSMaxRange(selection) == GetTextLength();
 }