[iOS/ARC] Fix a violation of ODR in base::BindBlock under ARC.

ios/web/webui/crw_web_ui_manager.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.
 
 #import "ios/web/webui/crw_web_ui_manager.h"
 
 #include "base/json/string_escape.h"
 #include "base/mac/bind_objc_block.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/memory/ref_counted_memory.h"
@@ skipping 73 matching lines @@
   return self;
 }
 
 - (instancetype)initWithWebState:(web::WebStateImpl*)webState {
   if (self = [super init]) {
     _webState = webState;
     _webStateObserverBridge.reset(
         new web::WebStateObserverBridge(webState, self));
     base::WeakNSObject<CRWWebUIManager> weakSelf(self);
     _webState->AddScriptCommandCallback(
-        base::BindBlock(
+        base::BindBlockArc(
             ^bool(const base::DictionaryValue& message, const GURL&, bool) {
               return [weakSelf handleWebUIJSMessage:message];
             }),
         kScriptCommandPrefix);
   }
   return self;
 }
 
 - (void)dealloc {
   [self resetWebState];
@@ skipping 227 matching lines @@
 
 - (std::unique_ptr<web::URLFetcherBlockAdapter>)
     fetcherForURL:(const GURL&)URL
 completionHandler:(web::URLFetcherBlockAdapterCompletion)handler {
   return std::unique_ptr<web::URLFetcherBlockAdapter>(
       new web::URLFetcherBlockAdapter(
           URL, _webState->GetBrowserState()->GetRequestContext(), handler));
 }
 
 @end