Reland of [ObjC ARC] Converts ios/chrome/browser/ui/contextual_search:contextual_search to ARC.

ios/chrome/browser/ui/contextual_search/contextual_search_results_view.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.
 
 #include "ios/chrome/browser/ui/contextual_search/contextual_search_results_view.h"
 
 #include <memory>
 
 #import "base/ios/weak_nsobject.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/memory/ptr_util.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #import "ios/chrome/browser/tabs/legacy_tab_helper.h"
 #import "ios/chrome/browser/tabs/tab.h"
 #import "ios/chrome/browser/tabs/tab_helper_util.h"
 #import "ios/chrome/browser/tabs/tab_private.h"
 #import "ios/chrome/browser/ui/contextual_search/contextual_search_metrics.h"
 #import "ios/chrome/browser/ui/contextual_search/contextual_search_panel_view.h"
 #import "ios/chrome/browser/ui/contextual_search/contextual_search_web_state_observer.h"
 #import "ios/chrome/browser/web_state_list/web_state_opener.h"
 #import "ios/chrome/common/material_timing.h"
 #include "ios/web/public/load_committed_details.h"
 #import "ios/web/public/serializable_user_data_manager.h"
 #import "ios/web/public/web_state/ui/crw_native_content_provider.h"
 #import "ios/web/public/web_state/ui/crw_web_view_proxy.h"
 #import "ios/web/public/web_state/ui/crw_web_view_scroll_view_proxy.h"
 #import "ios/web/public/web_state/web_state.h"
 #import "ios/web/web_state/ui/crw_web_controller.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 enum SearchResultsViewVisibility { OFFSCREEN, PRELOAD, VISIBLE };
 }
 
 @interface ContextualSearchResultsView ()<ContextualSearchWebStateDelegate,
                                           CRWNativeContentProvider>
 
 // Can the search results be scrolled currently?
 @property(nonatomic, assign, getter=isScrollEnabled) BOOL scrollEnabled;
 @end
 
 @implementation ContextualSearchResultsView {
-  base::WeakNSProtocol<id<ContextualSearchTabPromoter>> _promoter;
-  base::WeakNSProtocol<id<ContextualSearchPreloadChecker>> _preloadChecker;
   std::unique_ptr<ContextualSearchWebStateObserver> _webStateObserver;
 
   // WebState that loads the search results.
   std::unique_ptr<web::WebState> _webState;
   std::unique_ptr<WebStateOpener> _webStateOpener;
 
   // Access to the search tab's web view proxy.
-  base::scoped_nsprotocol<id<CRWWebViewProxy>> _webViewProxy;
+  id<CRWWebViewProxy> _webViewProxy;
 
   BOOL _loaded;
   BOOL _displayed;
   BOOL _loadingError;
   BOOL _waitingForInitialSearchTabLoad;
   BOOL _loadInProgress;
   BOOL _shouldScroll;
 
   BOOL _preloadEnabled;
 
   SearchResultsViewVisibility _visibility;
 
   // Time of starting a search results page load.
   base::Time _loadStartTime;
 }
 
 @synthesize active = _active;
 @synthesize opener = _opener;
+@synthesize promoter = _promoter;
+@synthesize preloadChecker = _preloadChecker;
 
 - (instancetype)initWithFrame:(CGRect)frame {
   if ((self = [super initWithFrame:frame])) {
     self.translatesAutoresizingMaskIntoConstraints = NO;
     self.backgroundColor = [UIColor whiteColor];
     self.accessibilityIdentifier = @"contextualSearchResultsView";
     self.clipsToBounds = YES;
     _webStateObserver.reset(new ContextualSearchWebStateObserver(self));
     _visibility = OFFSCREEN;
   }
@@ skipping 11 matching lines @@
   [[_webViewProxy scrollViewProxy] setBounces:NO];
 }
 
 #pragma mark - public properties
 
 - (id<ContextualSearchTabPromoter>)promoter {
   return _promoter;
 }
 
 - (void)setPromoter:(id<ContextualSearchTabPromoter>)promoter {
-  _promoter.reset(promoter);
+  _promoter = promoter;
 }
 
 - (id<ContextualSearchPreloadChecker>)preloadChecker {
   return _preloadChecker;
 }
 
 - (void)setPreloadChecker:(id<ContextualSearchPreloadChecker>)preloadChecker {
-  _preloadChecker.reset(preloadChecker);
+  _preloadChecker = preloadChecker;
 }
 
 - (BOOL)contentVisible {
   return _loaded && _visibility == VISIBLE;
 }
 
 - (void)setActive:(BOOL)active {
   if (active) {
     if (_webState) {
       Tab* tab = LegacyTabHelper::GetTabForWebState(_webState.get());
       // Start watching the embedded Tab's web activity.
       _webStateObserver->ObserveWebState(_webState.get());
       _webState->SetShouldSuppressDialogs(false);
 
-      _webViewProxy.reset([[[tab webController] webViewProxy] retain]);
+      _webViewProxy = [[tab webController] webViewProxy];
       [[_webViewProxy scrollViewProxy] setBounces:NO];
     }
   } else {
     // Stop watching the embedded Tab's web activity.
     _webStateObserver->ObserveWebState(nullptr);
-    _webViewProxy.reset(nil);
+    _webViewProxy = nil;
   }
 
   _active = active;
 }
 
 #pragma mark - public methods
 
 - (void)scrollToTopAnimated:(BOOL)animated {
   [[_webViewProxy scrollViewProxy] setBounces:YES];
   // Scroll the search tab's view to the top.
@@ skipping 50 matching lines @@
 
 #pragma mark - private methods
 
 - (void)disconnectTab {
   if (_webState) {
     Tab* tab = LegacyTabHelper::GetTabForWebState(_webState.get());
     [[tab view] removeFromSuperview];
     [[tab webController] setNativeProvider:nil];
   }
   self.active = NO;
-  _webViewProxy.reset();
+  _webViewProxy = nil;
 }
 
 - (void)cancelLoad {
   [self disconnectTab];
   _loadInProgress = NO;
   _loaded = NO;
   _webState.reset();
 }
 
 - (void)loadPendingSearchIfPossible {
@@ skipping 169 matching lines @@
                                                        withError:error
                                                           isPost:isPost];
 
   if ([errorController respondsToSelector:@selector(setScrollEnabled:)]) {
     [errorController setScrollEnabled:NO];
   }
   return errorController;
 }
 
 @end