Update some uses of char16 to use the base:: namespace.

chrome/browser/autocomplete/search_provider.cc

 // Copyright 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/autocomplete/search_provider.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/callback.h"
@@ skipping 411 matching lines @@
     match.description = annotation;
 
   match.allowed_to_be_default_match = (input_text == match_contents);
 
   // When the user forced a query, we need to make sure all the fill_into_edit
   // values preserve that property.  Otherwise, if the user starts editing a
   // suggestion, non-Search results will suddenly appear.
   if (input.type() == AutocompleteInput::FORCED_QUERY)
     match.fill_into_edit.assign(base::ASCIIToUTF16("?"));
   if (is_keyword)
-    match.fill_into_edit.append(match.keyword + char16(' '));
+    match.fill_into_edit.append(match.keyword + base::char16(' '));
   if (!input.prevent_inline_autocomplete() &&
       StartsWith(query_string, input_text, false)) {
     match.inline_autocompletion = query_string.substr(input_text.length());
     match.allowed_to_be_default_match = true;
   }
   match.fill_into_edit.append(query_string);
 
   const TemplateURLRef& search_url = template_url->url_ref();
   DCHECK(search_url.SupportsReplacement());
   match.search_terms_args.reset(
@@ skipping 1595 matching lines @@
   if (!OmniboxFieldTrial::InZeroSuggestFieldTrial() ||
       service == NULL ||
       !service->IsSyncEnabledAndLoggedIn() ||
       !sync_prefs.GetPreferredDataTypes(syncer::UserTypes()).Has(
           syncer::PROXY_TABS) ||
       service->GetEncryptedDataTypes().Has(syncer::SESSIONS))
     return false;
 
   return true;
 }