Converts parts of ios/web to ARC

ios/web/browser_url_rewriter_impl.mm

 // Copyright 2015 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 "ios/web/browser_url_rewriter_impl.h"
 
 #include "base/logging.h"
 #include "base/strings/string_util.h"
 #include "ios/web/public/browser_state.h"
 #include "ios/web/public/web_client.h"
 #include "url/gurl.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace web {
 
 namespace {
 
 // The scheme used to view the source of a page using WebUI in content/.
 const char kViewSourceScheme[] = "view-source";
 
 // Handles rewriting view-source URLs for what we'll actually load.  Since
 // WebUI-based view-source isn't supported on iOS, simply strip out the scheme
 // and load the URL.  This is to gracefully handle tabs synced from other
@@ skipping 49 matching lines @@
 }
 
 bool BrowserURLRewriterImpl::RewriteURLIfNecessary(
     GURL* url,
     BrowserState* browser_state) {
   return BrowserURLRewriter::RewriteURLWithWriters(url, browser_state,
                                                    url_rewriters_);
 }
 
 }  // namespace web