[ARC] [Split this CL] Convert ios/web/webui to ARC.

ios/web/webui/crw_web_ui_page_builder.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.
 
 #include "ios/web/webui/crw_web_ui_page_builder.h"
 
 #include <map>
 #include <string>
 #include <vector>
 
-#include "base/ios/weak_nsobject.h"
 #include "base/logging.h"
 #include "base/mac/bundle_locations.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // Prefix for script tags. Used to locate JavaScript subresources.
 NSString* const kJSTagPrefix = @"<script src=\"";
 // Suffix for script tags. Used to locate JavaScript subresources.
 NSString* const kJSTagSuffix = @"\"></script>";
 // Prefix for stylesheet tags. Used to locate CSS subresources.
 NSString* const kCSSTagPrefix = @"<link rel=\"stylesheet\" href=\"";
 // Suffix for stylesheet tags. Used to locate CSS subresources.
 NSString* const kCSSTagSuffix = @"\">";
 // Template for creating inlined JavaScript tags.
@@ skipping 58 matching lines @@
     withSubresources:(const std::map<GURL, std::string>&)subresources;
 
 // Returns JavaScript needed for bridging WebUI chrome.send() messages to
 // the core.js defined message delivery system.
 - (NSString*)webUIJavaScript;
 
 @end
 
 @implementation CRWWebUIPageBuilder {
   // Delegate for requesting resources.
-  base::WeakNSProtocol<id<CRWWebUIPageBuilderDelegate>> _delegate;
+  __weak id<CRWWebUIPageBuilderDelegate> _delegate;
 }
 
 #pragma mark - Public Methods
 
 - (instancetype)init {
   NOTREACHED();
   return self;
 }
 
 - (instancetype)initWithDelegate:(id<CRWWebUIPageBuilderDelegate>)delegate {
   if (self = [super init]) {
-    _delegate.reset(delegate);
+    _delegate = delegate;
   }
   return self;
 }
 
 - (void)buildWebUIPageForURL:(const GURL&)webUIURL
            completionHandler:(web::WebUIPageCompletion)completionHandler {
   [self fetchResourceWithURL:webUIURL
            completionHandler:^(NSString* webUIHTML, const GURL& URL) {
              [self buildWebUIPageForHTML:webUIHTML
                                 webUIURL:URL
                        completionHandler:completionHandler];
            }];
 }
 
 #pragma mark - Private Methods
 
 - (void)buildWebUIPageForHTML:(NSString*)HTML
                      webUIURL:(const GURL&)pageURL
             completionHandler:(web::WebUIPageCompletion)completionHandler {
   __block base::scoped_nsobject<NSMutableString> webUIHTML([HTML mutableCopy]);
   NSSet* subresourceURLStrings = [self URLStringsFromHTML:webUIHTML];
   __block NSUInteger pendingSubresourceCount = [subresourceURLStrings count];
   if (!pendingSubresourceCount) {
     completionHandler(webUIHTML);
     return;
   }
   __block std::map<GURL, std::string> subresources;
-  base::WeakNSObject<CRWWebUIPageBuilder> weakSelf(self);
+  __weak CRWWebUIPageBuilder* weakSelf = self;
   // Completion handler for subresource loads.
-  __block web::WebUIDelegateCompletion subresourceHandler = nil;
-  subresourceHandler = [[^(NSString* subresource, const GURL& subresourceURL) {
+  web::WebUIDelegateCompletion subresourceHandler = nil;
+  __block __weak web::WebUIDelegateCompletion weakSubresourceHandler = nil;
+  subresourceHandler = [^(NSString* subresource, const GURL& subresourceURL) {
     // Import statements in CSS resources are also loaded.
     if ([self isCSSSubresourceURL:subresourceURL]) {
       NSSet* URLStrings = [weakSelf URLStringsFromCSS:subresource];
       for (NSString* URLString in URLStrings) {
         GURL URL(subresourceURL.Resolve(base::SysNSStringToUTF8(URLString)));
         [weakSelf addCSSTagToHTML:webUIHTML
                            forURL:URL
                         sourceURL:subresourceURL];
         ++pendingSubresourceCount;
         [weakSelf fetchResourceWithURL:URL
-                     completionHandler:subresourceHandler];
+                     completionHandler:weakSubresourceHandler];
       }
     }
     subresources[subresourceURL] = base::SysNSStringToUTF8(subresource);
     --pendingSubresourceCount;
     // When subresource loading is complete, flatten the default resource
     // and invoke the completion handler.
     if (!pendingSubresourceCount) {
       [weakSelf flattenHTML:webUIHTML withSubresources:subresources];
       completionHandler(webUIHTML);
     }
-  } copy] autorelease];
+  } copy];
+
+  weakSubresourceHandler = subresourceHandler;
 
   for (NSString* URLString in subresourceURLStrings) {
     // chrome://resources/js/ios/web_ui.js is skipped because it is
     // retrieved via webUIJavaScript rather than the net stack.
     if ([URLString isEqualToString:kWebUIJSURL]) {
       --pendingSubresourceCount;
       if (!pendingSubresourceCount) {
         [weakSelf flattenHTML:webUIHTML withSubresources:subresources];
         completionHandler(webUIHTML);
       }
@@ skipping 143 matching lines @@
 - (NSString*)webUIJavaScript {
   NSBundle* bundle = base::mac::FrameworkBundle();
   NSString* path = [bundle pathForResource:@"web_ui_bundle" ofType:@"js"];
   DCHECK(path) << "web_ui_bundle.js file not found";
   return [NSString stringWithContentsOfFile:path
                                    encoding:NSUTF8StringEncoding
                                       error:nil];
 }
 
 @end