[ObjC ARC] Converts ios/chrome/test/earl_grey:test_support to ARC.

ios/chrome/test/earl_grey/chrome_matchers.mm

 // Copyright 2016 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/chrome/test/earl_grey/chrome_matchers.h"
 
 #import <OCHamcrest/OCHamcrest.h>
 
 #import <WebKit/WebKit.h>
 
 #include "base/mac/foundation_util.h"
 #include "base/strings/sys_string_conversions.h"
 #import "base/test/ios/wait_util.h"
 #include "components/strings/grit/components_strings.h"
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_switch_item.h"
 #import "ios/chrome/browser/ui/omnibox/omnibox_text_field_ios.h"
 #import "ios/chrome/browser/ui/static_content/static_html_view_controller.h"
 #import "ios/chrome/browser/ui/toolbar/toolbar_controller.h"
 #include "ios/chrome/grit/ios_strings.h"
 #import "ios/chrome/test/app/chrome_test_util.h"
 #import "ios/testing/wait_util.h"
 #import "ios/web/public/block_types.h"
 #import "ios/web/public/test/earl_grey/web_view_matchers.h"
 #include "ui/base/l10n/l10n_util.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 // Script that returns document.body as a string.
 NSString* const kGetDocumentBodyJavaScript =
     @"document.body ? document.body.textContent : null";
 
 // Synchronously returns the result of executed JavaScript.
 id ExecuteScriptInStaticController(
     StaticHtmlViewController* html_view_controller,
     NSString* script) {
   __block id result = nil;
   __block bool did_finish = false;
   web::JavaScriptResultBlock completion_handler =
       ^(id script_result, NSError* error) {
         result = [script_result copy];
         did_finish = true;
       };
   [html_view_controller executeJavaScript:script
                         completionHandler:completion_handler];
 
   GREYAssert(
       testing::WaitUntilConditionOrTimeout(testing::kWaitForJSCompletionTimeout,
                                            ^{
                                              return did_finish;
                                            }),
       @"JavaScript did not complete");
 
-  return [result autorelease];
+  return result;
 }
 
 // TODO(crbug.com/684142): This matcher uses too many implementation details,
 // it would be good to replace it.
 id<GREYMatcher> WebViewWithNavDelegateOfClass(Class cls) {
   MatchesBlock matches = ^BOOL(UIView* view) {
     return [view isKindOfClass:[WKWebView class]] &&
            [base::mac::ObjCCast<WKWebView>(view).navigationDelegate
                isKindOfClass:cls];
   };
 
   DescribeToBlock describe = ^(id<GREYDescription> description) {
     [description appendText:@"web view with "];
     [description appendText:NSStringFromClass(cls)];
     [description appendText:@"navigation delegate"];
   };
 
-  return [[[GREYElementMatcherBlock alloc] initWithMatchesBlock:matches
-                                               descriptionBlock:describe]
-      autorelease];
+  return [[GREYElementMatcherBlock alloc] initWithMatchesBlock:matches
+                                              descriptionBlock:describe];
 }
 
 id<GREYMatcher> CollectionViewSwitchIsOn(BOOL isOn) {
   MatchesBlock matches = ^BOOL(id element) {
     CollectionViewSwitchCell* switchCell =
         base::mac::ObjCCastStrict<CollectionViewSwitchCell>(element);
     UISwitch* switchView = switchCell.switchView;
     return (switchView.on && isOn) || (!switchView.on && !isOn);
   };
   DescribeToBlock describe = ^void(id<GREYDescription> description) {
     NSString* name =
         [NSString stringWithFormat:@"collectionViewSwitchInState(%@)",
                                    isOn ? @"ON" : @"OFF"];
     [description appendText:name];
   };
-  return [[[GREYElementMatcherBlock alloc] initWithMatchesBlock:matches
-                                               descriptionBlock:describe]
-      autorelease];
+  return [[GREYElementMatcherBlock alloc] initWithMatchesBlock:matches
+                                              descriptionBlock:describe];
 }
 
 }  // namespace
 
 namespace chrome_test_util {
 
 id<GREYMatcher> ButtonWithAccessibilityLabel(NSString* label) {
   return grey_allOf(grey_accessibilityLabel(label),
                     grey_accessibilityTrait(UIAccessibilityTraitButton), nil);
 }
@@ skipping 47 matching lines @@
     return did_succeed;
   };
 
   DescribeToBlock describe = ^(id<GREYDescription> description) {
     [description appendText:@"static HTML web view containing "];
     [description appendText:text];
   };
 
   return grey_allOf(
       WebViewWithNavDelegateOfClass([StaticHtmlViewController class]),
-      [[[GREYElementMatcherBlock alloc] initWithMatchesBlock:matches
-                                            descriptionBlock:describe]
-          autorelease],
+      [[GREYElementMatcherBlock alloc] initWithMatchesBlock:matches
+                                           descriptionBlock:describe],
       nil);
 }
 
 id<GREYMatcher> WebViewContainingBlockedImage(std::string image_id) {
   return web::WebViewContainingBlockedImage(
       std::move(image_id), chrome_test_util::GetCurrentWebState());
 }
 
 id<GREYMatcher> WebViewContainingLoadedImage(std::string image_id) {
   return web::WebViewContainingLoadedImage(
@@ skipping 48 matching lines @@
 }
 
 id<GREYMatcher> CollectionViewSwitchCell(NSString* accessibilityIdentifier,
                                          BOOL isOn) {
   return grey_allOf(grey_accessibilityID(accessibilityIdentifier),
                     CollectionViewSwitchIsOn(isOn), grey_sufficientlyVisible(),
                     nil);
 }
 
 }  // namespace chrome_test_util