Minor cleanup in ios/web utils

Addresses minor comments from upstreaming ios/web utility code in
a previous CL (<https://codereview.chromium.org/988383002/>)

BUG=None

Review URL: https://codereview.chromium.org/1023013002

Cr-Commit-Position: refs/heads/master@{#321579}

ios/web/crw_network_activity_indicator_manager.mm

@@ -26,7 +26,7 @@
   return instance;
 }
 
-- (id)init {
+- (instancetype)init {
   self = [super init];
   if (self) {
     _groupCounts.reset([[NSMutableDictionary alloc] init]);
@@ -54,8 +54,7 @@
     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];
@@ -74,8 +73,7 @@
   if (count == 0) {
     [_groupCounts removeObjectForKey:group];
   } else {
-    [_groupCounts setObject:[NSNumber numberWithUnsignedInteger:count]
-                     forKey:group];
+    [_groupCounts setObject:@(count) forKey:group];
   }
   _totalCount -= numTasks;
   if (_totalCount == 0) {
@@ -111,5 +109,4 @@
   return _totalCount;
 }
 
-
 @end

ios/web/history_state_util.h

@@ -5,8 +5,6 @@
 #ifndef IOS_WEB_HISTORY_STATE_UTIL_H_
 #define IOS_WEB_HISTORY_STATE_UTIL_H_
 
-#import <Foundation/Foundation.h>
-
 #include <string>
 
 class GURL;

ios/web/history_state_util_unittest.mm

@@ -2,9 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#import <Foundation/Foundation.h>
-
 #import "ios/web/history_state_util.h"
+
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/gtest_mac.h"
 #include "url/gurl.h"

ios/web/navigation/nscoder_util.mm

@@ -16,7 +16,7 @@ void EncodeString(NSCoder* coder, NSString* key, const std::string& string) {
 }
 
 std::string DecodeString(NSCoder* decoder, NSString* key) {
-  NSUInteger length;
+  NSUInteger length = 0;
   const uint8_t* bytes = [decoder decodeBytesForKey:key returnedLength:&length];
   return std::string(reinterpret_cast<const char*>(bytes), length);
 }

ios/web/web_state/blocked_popup_info.mm

@@ -13,7 +13,7 @@ BlockedPopupInfo::BlockedPopupInfo(const GURL& url,
     : url_(url),
       referrer_(referrer),
       window_name_([window_name copy]),
-      show_popup_handler_([show_popup_handler copy]){
+      show_popup_handler_([show_popup_handler copy]) {
 }
 
 BlockedPopupInfo::BlockedPopupInfo(const BlockedPopupInfo& blocked_popup_info)