Correct iOS build for latest Xcode beta.

ios/chrome/browser/updatable_config/updatable_config_base.mm

 // Copyright 2013 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/chrome/browser/updatable_config/updatable_config_base.h"
 
 #include "base/logging.h"
 #import "base/mac/bind_objc_block.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/memory/ref_counted.h"
@@ skipping 95 matching lines @@
   scoped_refptr<net::URLRequestContextGetter> _requestContextGetter;
 }
 
 + (void)enableConsistencyCheck {
 #if !defined(NDEBUG)
   g_consistency_check_enabled = YES;
 #endif
 }
 
 // Overrides default designated initializer.
-- (instancetype)init {
-  NOTREACHED();
-  return nil;
-}
-
 - (instancetype)initWithAppId:(NSString*)appId
                       version:(NSString*)appVersion
                         plist:(NSString*)plistName {
   self = [super init];
   if (self) {
     _updatableResource.reset([self newResource:plistName]);
     // UpdatableResourceBridge initializes the appId to what is in the
     // application bundle. The following overrides that with either the |appId|
     // passed in or a default based on experimental settings if |appId| is nil.
     if (!appId)
@@ skipping 19 matching lines @@
                name:notificationName
              object:[_updatableResource descriptor]];
 
 #if !defined(NDEBUG)
     [self scheduleConsistencyCheck];
 #endif
   }
   return self;
 }
 
+- (instancetype)init {
+  NOTREACHED();
+  return nil;
+}
+
 - (void)dealloc {
   [[NSNotificationCenter defaultCenter] removeObserver:self];
 #if !defined(NDEBUG)
   [self cancelConsistencyCheck];
 #endif
   [super dealloc];
 }
 
 - (void)startUpdate:(net::URLRequestContextGetter*)requestContextGetter {
 #if !defined(NDEBUG)
@@ skipping 87 matching lines @@
     return;
   if (!_configFetcher) {
     _configFetcher.reset(
         new ConfigFetcher(self, [_updatableResource descriptor]));
   }
   GURL url = net::GURLWithNSURL([[_updatableResource descriptor] updateURL]);
   _configFetcher->Fetch(url, _requestContextGetter.get());
 }
 
 @end