Correct iOS build for latest Xcode beta.

ios/net/request_tracker.mm

 // 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 "ios/net/request_tracker.h"
 
 #include "base/logging.h"
 #import "ios/net/clients/crn_forwarding_network_client.h"
 #import "ios/net/clients/crn_forwarding_network_client_factory.h"
 
@@ skipping 16 matching lines @@
 
   // Gets the factories.
   NSArray* GetFactories() {
     DCHECK(thread_checker_.CalledOnValidThread());
     return factories_.get();
   }
 
   // Adds a factory.
   void AddFactory(CRNForwardingNetworkClientFactory* factory) {
     DCHECK(thread_checker_.CalledOnValidThread());
-    DCHECK_EQ(NSNotFound, [factories_ indexOfObject:factory]);
+    // TODO(justincohen): Cast indexOfObject to work around Xcode beta bugs.
+    // Revisit in future betas where hopefully these types match again.
+    // crbug.com/498825
+    DCHECK_EQ(NSNotFound,
+              static_cast<NSInteger>([factories_ indexOfObject:factory]));
     DCHECK(!IsSelectorOverriden(factory, @selector(clientHandlingRequest:)));
     DCHECK(!IsSelectorOverriden(factory,
                                 @selector(clientHandlingResponse:request:)));
     DCHECK(!IsSelectorOverriden(
                factory, @selector(clientHandlingRedirect:url:response:)));
     [factories_ addObject:factory];
   }
 
   // Returns true if |factory| re-implements |selector|.
   // Only used for debugging.
@@ skipping 166 matching lines @@
   DCHECK(thread_checker_.CalledOnValidThread());
   return cache_mode_;
 }
 
 void RequestTracker::SetCacheMode(RequestTracker::CacheMode mode) {
   DCHECK(thread_checker_.CalledOnValidThread());
   cache_mode_ = mode;
 }
 
 }  // namespace net