[ARC] Converts part of ios/web/ui to ARC.

ios/web/webui/crw_web_ui_manager.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.
 
 #import "ios/web/webui/crw_web_ui_manager.h"
 
 #include "base/json/string_escape.h"
 #include "base/mac/bind_objc_block.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/memory/scoped_vector.h"
 #include "base/strings/stringprintf.h"
 #import "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "ios/web/grit/ios_web_resources.h"
 #import "ios/web/net/request_group_util.h"
 #include "ios/web/public/browser_state.h"
 #include "ios/web/public/web_client.h"
 #import "ios/web/public/web_state/web_state_observer_bridge.h"
 #include "ios/web/web_state/web_state_impl.h"
 #import "ios/web/webui/crw_web_ui_page_builder.h"
 #include "ios/web/webui/mojo_js_constants.h"
 #include "ios/web/webui/url_fetcher_block_adapter.h"
 #include "mojo/public/js/constants.h"
 #import "net/base/mac/url_conversions.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // Prefix for history.requestFavicon JavaScript message.
 const char kScriptCommandPrefix[] = "webui";
 }
 
 @interface CRWWebUIManager () <CRWWebUIPageBuilderDelegate>
 
 // Current web state.
 @property(nonatomic, readonly) web::WebStateImpl* webState;
 
@@ skipping 53 matching lines @@
             ^bool(const base::DictionaryValue& message, const GURL&, bool) {
               return [weakSelf handleWebUIJSMessage:message];
             }),
         kScriptCommandPrefix);
   }
   return self;
 }
 
 - (void)dealloc {
   [self resetWebState];
-  [super dealloc];
 }
 
 #pragma mark - CRWWebStateObserver Methods
 
 - (void)webState:(web::WebState*)webState
     didStartProvisionalNavigationForURL:(const GURL&)URL {
   DCHECK(webState == _webState);
   // If URL is not an application specific URL, ignore the navigation.
   if (!web::GetWebClient()->IsAppSpecificURL(URL))
     return;
@@ skipping 95 matching lines @@
   std::string favicon;
   if (!arguments->GetString(0, &favicon)) {
     DLOG(WARNING) << "JS message parameter not found: Favicon URL";
     return NO;
   }
   GURL faviconURL(favicon);
   DCHECK(faviconURL.is_valid());
   // Retrieve favicon resource and set favicon background image via JavaScript.
   base::WeakNSObject<CRWWebUIManager> weakSelf(self);
   void (^faviconHandler)(NSData*) = ^void(NSData* data) {
-    base::scoped_nsobject<CRWWebUIManager> strongSelf([weakSelf retain]);
+    base::scoped_nsobject<CRWWebUIManager> strongSelf(weakSelf);
     if (!strongSelf)
       return;
     NSString* base64EncodedResource = [data base64EncodedStringWithOptions:0];
     NSString* dataURLString = [NSString
         stringWithFormat:@"data:image/png;base64,%@", base64EncodedResource];
     NSString* faviconURLString = base::SysUTF8ToNSString(faviconURL.spec());
     NSString* script =
         [NSString stringWithFormat:@"chrome.setFaviconBackground('%@', '%@');",
                                    faviconURLString, dataURLString];
     [strongSelf webState]->ExecuteJavaScript(base::SysNSStringToUTF16(script));
@@ skipping 101 matching lines @@
 
 - (std::unique_ptr<web::URLFetcherBlockAdapter>)
     fetcherForURL:(const GURL&)URL
 completionHandler:(web::URLFetcherBlockAdapterCompletion)handler {
   return std::unique_ptr<web::URLFetcherBlockAdapter>(
       new web::URLFetcherBlockAdapter(
           URL, _webState->GetBrowserState()->GetRequestContext(), handler));
 }
 
 @end