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

ios/chrome/browser/ui/contextual_search/touch_to_search_permissions_mediator_unittest.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/browser/ui/contextual_search/touch_to_search_permissions_mediator.h"
 
 #import <UIKit/UIKit.h>
 #include <memory>
 
 #include "base/command_line.h"
@@ skipping 486 matching lines @@
   EXPECT_FALSE([permissions canEnable]);
 
   EXPECT_EQ(nil, [permissions audience]);
   id audience = [OCMockObject
       niceMockForProtocol:@protocol(TouchToSearchPermissionsChangeAudience)];
   [permissions setAudience:audience];
   EXPECT_EQ(nil, [permissions audience]);
 }
 
 TEST_F(TouchToSearchPermissionsMediatorTest, AudienceRemovedNotifications) {
-  base::scoped_nsobject<id> audience(
-      [[TestTouchToSearchPermissionsAudience alloc] init]);
-  [tts_permissions_ setAudience:audience];
-  EXPECT_TRUE([tts_permissions_ observing]);
-  audience.reset();
+  @autoreleasepool {
+    base::scoped_nsobject<id> audience(
+        [[TestTouchToSearchPermissionsAudience alloc] init]);
+    [tts_permissions_ setAudience:audience];
+    EXPECT_TRUE([tts_permissions_ observing]);
+    audience.reset();
+  }
   // Permissions shouldn't be observing after notifying a nil audience.
   [[NSNotificationCenter defaultCenter]
       postNotificationName:UIAccessibilityVoiceOverStatusChanged
                     object:nil];
   EXPECT_FALSE([tts_permissions_ observing]);
 
   // Permissions shouldn't observe while still observing.
-  audience.reset([[TestTouchToSearchPermissionsAudience alloc] init]);
+  base::scoped_nsobject<id> audience(
+      [[TestTouchToSearchPermissionsAudience alloc] init]);
   [tts_permissions_ setAudience:audience];
   audience.reset();
   audience.reset([[TestTouchToSearchPermissionsAudience alloc] init]);
   [tts_permissions_ setAudience:audience];
 }
 
 #pragma mark - Unit tests for availability class method.
 
 TEST(TouchToSearchPermissionsAvailabilityTest, CommandLinePermissions) {
   const struct {
@@ skipping 97 matching lines @@
       TouchToSearch::DISABLED, TouchToSearch::UNDECIDED, TouchToSearch::ENABLED,
   };
 
   for (const auto& state : states) {
     permissions.preferenceState = state;
     EXPECT_EQ(state, permissions.preferenceState);
   }
 }
 
 }  // namespace