Minor cleanup in ios/web utils

ios/web/crw_network_activity_indicator_manager.mm

 // Copyright 2014 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/crw_network_activity_indicator_manager.h"
 
 #import <UIKit/UIKit.h>
 
 #include "base/logging.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/threading/thread_checker.h"
 
 @interface CRWNetworkActivityIndicatorManager () {
   base::scoped_nsobject<NSMutableDictionary> _groupCounts;
   NSUInteger _totalCount;
   base::ThreadChecker _threadChecker;
 }
 
 @end
 
 @implementation CRWNetworkActivityIndicatorManager
 
 + (CRWNetworkActivityIndicatorManager*)sharedInstance {
   static CRWNetworkActivityIndicatorManager* instance =
       [[CRWNetworkActivityIndicatorManager alloc] init];
   return instance;
 }
 
-- (id)init {
+- (instancetype)init {
   self = [super init];
   if (self) {
     _groupCounts.reset([[NSMutableDictionary alloc] init]);
     _totalCount = 0;
   }
   return self;
 }
 
 - (void)startNetworkTaskForGroup:(NSString*)group {
   [self startNetworkTasks:1 forGroup:group];
 }
 
 - (void)stopNetworkTaskForGroup:(NSString*)group {
   [self stopNetworkTasks:1 forGroup:group];
 }
 
 - (void)startNetworkTasks:(NSUInteger)numTasks forGroup:(NSString*)group {
   DCHECK(_threadChecker.CalledOnValidThread());
   DCHECK(group);
   DCHECK_GT(numTasks, 0U);
   NSUInteger count = 0;
   NSNumber* number = [_groupCounts objectForKey:group];
   if (number) {
     count = [number unsignedIntegerValue];
     DCHECK_GT(count, 0U);
   }
   count += numTasks;
-  [_groupCounts setObject:[NSNumber numberWithUnsignedInteger:count]
-                   forKey:group];
+  [_groupCounts setObject:@(count) forKey:group];
   _totalCount += numTasks;
   if (_totalCount == numTasks) {
     [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
   }
 }
 
 - (void)stopNetworkTasks:(NSUInteger)numTasks forGroup:(NSString*)group {
   DCHECK(_threadChecker.CalledOnValidThread());
   DCHECK(group);
   DCHECK_GT(numTasks, 0U);
   NSNumber* number = [_groupCounts objectForKey:group];
   DCHECK(number);
   NSUInteger count = [number unsignedIntegerValue];
   DCHECK(count >= numTasks);
   count -= numTasks;
   if (count == 0) {
     [_groupCounts removeObjectForKey:group];
   } else {
-    [_groupCounts setObject:[NSNumber numberWithUnsignedInteger:count]
-                     forKey:group];
+    [_groupCounts setObject:@(count) forKey:group];
   }
   _totalCount -= numTasks;
   if (_totalCount == 0) {
     [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
   }
 }
 
 - (NSUInteger)clearNetworkTasksForGroup:(NSString*)group {
   DCHECK(_threadChecker.CalledOnValidThread());
   DCHECK(group);
@@ skipping 15 matching lines @@
     return 0;
   }
   return [number unsignedIntegerValue];
 }
 
 - (NSUInteger)numTotalNetworkTasks {
   DCHECK(_threadChecker.CalledOnValidThread());
   return _totalCount;
 }
 
-
 @end