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

ios/web/webui/crw_web_ui_manager_unittest.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 <memory>
 
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
@@ skipping 51 matching lines @@
 
 // Mock of URLFetcherBlockAdapter to provide mock resources.
 class MockURLFetcherBlockAdapter : public URLFetcherBlockAdapter {
  public:
   MockURLFetcherBlockAdapter(
       const GURL& url,
       net::URLRequestContextGetter* request_context,
       URLFetcherBlockAdapterCompletion completion_handler)
       : URLFetcherBlockAdapter(url, request_context, completion_handler),
         url_(url),
-        completion_handler_(completion_handler) {}
+        completion_handler_([completion_handler copy]) {}
 
   void Start() override {
     if (url_.spec() == kFaviconUrl) {
       base::FilePath favicon_path;
       ASSERT_TRUE(PathService::Get(base::DIR_SOURCE_ROOT, &favicon_path));
       favicon_path = favicon_path.AppendASCII(kFaviconPath);
       NSData* favicon = [NSData
           dataWithContentsOfFile:base::SysUTF8ToNSString(favicon_path.value())];
       completion_handler_.get()(favicon, this);
     } else if (url_.path().find(kMojoModuleName) != std::string::npos) {
@@ skipping 112 matching lines @@
       "%s__crWeb.webUIModuleLoadNotifier.moduleLoadCompleted(\"%s\", \"%s\");",
       base::SysNSStringToUTF8(kMojoModule).c_str(), kMojoModuleName,
       kTestLoadId);
 
   EXPECT_CALL(*web_state_impl_,
               ExecuteJavaScript(base::UTF8ToUTF16(expected_javascript)));
   web_state_impl_->OnScriptCommandReceived("webui.loadMojo", message,
                                            GURL(kTestWebUIUrl), false);
 }
 }  // namespace web