[ObjC ARC] Converts ios/chrome/browser/metrics:unit_tests_internal to ARC.

ios/chrome/browser/metrics/size_class_recorder_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/chrome/browser/metrics/size_class_recorder.h"
 #import "ios/chrome/browser/metrics/size_class_recorder_private.h"
 
 #include <memory>
 
-#import "base/mac/scoped_nsobject.h"
 #include "base/test/histogram_tester.h"
 #import "ios/chrome/browser/ui/ui_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/platform_test.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 using ios_internal::SizeClassForReporting;
 using ios_internal::SizeClassForReportingForUIUserInterfaceSizeClass;
 
 namespace {
 
 const char kSizeClassUsedHistogramName[] = "Tab.HorizontalSizeClassUsed";
 
 const char kPageLoadSizeClassHistogramName[] =
     "Tab.PageLoadInHorizontalSizeClass";
 
 class SizeClassRecorderTest : public PlatformTest {
  protected:
   void SetUp() override {
     PlatformTest::SetUp();
     histogram_tester_.reset(new base::HistogramTester());
   }
 
-  base::scoped_nsobject<SizeClassRecorder> recorder_;
+  SizeClassRecorder* recorder_;
   std::unique_ptr<base::HistogramTester> histogram_tester_;
 };
 
 TEST_F(SizeClassRecorderTest, Initialization_SizeClassUnspecified) {
   // SizeClassRecoder is only available on iPad devices.
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified]);
-  recorder_.reset();
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
+  recorder_ = nil;
 
   histogram_tester_->ExpectTotalCount(kSizeClassUsedHistogramName, 0);
   histogram_tester_->ExpectTotalCount(kPageLoadSizeClassHistogramName, 0);
 }
 
 TEST_F(SizeClassRecorderTest, Initialization_SizeClassCompact) {
   // SizeClassRecoder is only available on iPad devices.
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassCompact]);
-  recorder_.reset();
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassCompact];
+  recorder_ = nil;
 
   histogram_tester_->ExpectTotalCount(kSizeClassUsedHistogramName, 0);
   histogram_tester_->ExpectTotalCount(kPageLoadSizeClassHistogramName, 0);
 }
 
 TEST_F(SizeClassRecorderTest, Initialization_SizeClassRegular) {
   // SizeClassRecoder is only available on iPad devices.
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassRegular]);
-  recorder_.reset();
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassRegular];
+  recorder_ = nil;
 
   histogram_tester_->ExpectTotalCount(kSizeClassUsedHistogramName, 0);
   histogram_tester_->ExpectTotalCount(kPageLoadSizeClassHistogramName, 0);
 }
 
 TEST_F(SizeClassRecorderTest, RecordInitialSizeClassOnAppBecomeActive) {
   // SizeClassRecoder is only available on iPad devices.
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassCompact]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassCompact];
   [[NSNotificationCenter defaultCenter]
       postNotificationName:UIApplicationDidBecomeActiveNotification
                     object:nil];
 
   histogram_tester_->ExpectUniqueSample(kSizeClassUsedHistogramName,
                                         SizeClassForReporting::COMPACT, 1);
   histogram_tester_->ExpectTotalCount(kPageLoadSizeClassHistogramName, 0);
 }
 
 TEST_F(SizeClassRecorderTest,
        DontRecordInitialSizeClassSubsequentAppBecomeActive) {
   // SizeClassRecoder is only available on iPad devices.
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassCompact]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassCompact];
   [[NSNotificationCenter defaultCenter]
       postNotificationName:UIApplicationDidBecomeActiveNotification
                     object:nil];
   [[NSNotificationCenter defaultCenter]
       postNotificationName:UIApplicationDidBecomeActiveNotification
                     object:nil];
 
   histogram_tester_->ExpectUniqueSample(kSizeClassUsedHistogramName,
                                         SizeClassForReporting::COMPACT, 1);
   histogram_tester_->ExpectTotalCount(kPageLoadSizeClassHistogramName, 0);
 }
 
 TEST_F(SizeClassRecorderTest, RecordSizeClassChangeInForeground) {
   // SizeClassRecoder is only available on iPad devices.
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
   [recorder_ horizontalSizeClassDidChange:UIUserInterfaceSizeClassRegular];
 
   histogram_tester_->ExpectUniqueSample(kSizeClassUsedHistogramName,
                                         SizeClassForReporting::REGULAR, 1);
   histogram_tester_->ExpectTotalCount(kPageLoadSizeClassHistogramName, 0);
 }
 
 TEST_F(SizeClassRecorderTest, DontRecordSizeClassChangeInBackground) {
   // SizeClassRecoder is only available on iPad devices.
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
   [[NSNotificationCenter defaultCenter]
       postNotificationName:UIApplicationDidEnterBackgroundNotification
                     object:nil];
   [recorder_ horizontalSizeClassDidChange:UIUserInterfaceSizeClassRegular];
 
   histogram_tester_->ExpectTotalCount(kSizeClassUsedHistogramName, 0);
   histogram_tester_->ExpectTotalCount(kPageLoadSizeClassHistogramName, 0);
 }
 
 TEST_F(SizeClassRecorderTest,
        RecordSizeClassChangeInForegroundAfterBackground) {
   // SizeClassRecoder is only available on iPad devices.
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
   [[NSNotificationCenter defaultCenter]
       postNotificationName:UIApplicationDidEnterBackgroundNotification
                     object:nil];
   [[NSNotificationCenter defaultCenter]
       postNotificationName:UIApplicationWillEnterForegroundNotification
                     object:nil];
   [recorder_ horizontalSizeClassDidChange:UIUserInterfaceSizeClassCompact];
 
   histogram_tester_->ExpectUniqueSample(kSizeClassUsedHistogramName,
                                         SizeClassForReporting::COMPACT, 1);
   histogram_tester_->ExpectTotalCount(kPageLoadSizeClassHistogramName, 0);
 }
 
 TEST_F(SizeClassRecorderTest, RecordSizeClassOnPageLoaded_Unspecified) {
   // SizeClassRecoder is only available on iPad devices.
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
   [recorder_
       pageLoadedWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
 
   histogram_tester_->ExpectTotalCount(kSizeClassUsedHistogramName, 0);
   histogram_tester_->ExpectUniqueSample(kPageLoadSizeClassHistogramName,
                                         SizeClassForReporting::UNSPECIFIED, 1);
 }
 
 TEST_F(SizeClassRecorderTest, RecordSizeClassOnPageLoaded_Compact) {
   // SizeClassRecoder is only available on iPad devices.
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
   [recorder_ pageLoadedWithHorizontalSizeClass:UIUserInterfaceSizeClassCompact];
 
   histogram_tester_->ExpectTotalCount(kSizeClassUsedHistogramName, 0);
   histogram_tester_->ExpectUniqueSample(kPageLoadSizeClassHistogramName,
                                         SizeClassForReporting::COMPACT, 1);
 }
 
 TEST_F(SizeClassRecorderTest, RecordSizeClassOnPageLoaded_Regular) {
   // SizeClassRecoder is only available on iPad devices.
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
   [recorder_ pageLoadedWithHorizontalSizeClass:UIUserInterfaceSizeClassRegular];
 
   histogram_tester_->ExpectTotalCount(kSizeClassUsedHistogramName, 0);
   histogram_tester_->ExpectUniqueSample(kPageLoadSizeClassHistogramName,
                                         SizeClassForReporting::REGULAR, 1);
 }
 
 }  // namespace