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

Automatically generated ARCMigrate commit
Notable issues:None
BUG=624363
TEST=None

Review-Url: https://codereview.chromium.org/2894653002
Cr-Commit-Position: refs/heads/master@{#475331}
diff --git a/ios/chrome/browser/metrics/BUILD.gn b/ios/chrome/browser/metrics/BUILD.gn
index 91c6ea4..f9703b0 100644
--- a/ios/chrome/browser/metrics/BUILD.gn
+++ b/ios/chrome/browser/metrics/BUILD.gn
@@ -129,6 +129,7 @@
 }
 
 source_set("unit_tests_internal") {
+  configs += [ "//build/config/compiler:enable_arc" ]
   testonly = true
   sources = [
     "first_user_action_recorder_unittest.cc",
diff --git a/ios/chrome/browser/metrics/size_class_recorder_unittest.mm b/ios/chrome/browser/metrics/size_class_recorder_unittest.mm
index 238e13a6..2709ad2f 100644
--- a/ios/chrome/browser/metrics/size_class_recorder_unittest.mm
+++ b/ios/chrome/browser/metrics/size_class_recorder_unittest.mm
@@ -7,12 +7,15 @@
 
 #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;
 
@@ -30,7 +33,7 @@
     histogram_tester_.reset(new base::HistogramTester());
   }
 
-  base::scoped_nsobject<SizeClassRecorder> recorder_;
+  SizeClassRecorder* recorder_;
   std::unique_ptr<base::HistogramTester> histogram_tester_;
 };
 
@@ -39,9 +42,9 @@
   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);
@@ -52,9 +55,9 @@
   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);
@@ -65,9 +68,9 @@
   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);
@@ -78,8 +81,8 @@
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassCompact]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassCompact];
   [[NSNotificationCenter defaultCenter]
       postNotificationName:UIApplicationDidBecomeActiveNotification
                     object:nil];
@@ -95,8 +98,8 @@
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassCompact]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassCompact];
   [[NSNotificationCenter defaultCenter]
       postNotificationName:UIApplicationDidBecomeActiveNotification
                     object:nil];
@@ -114,8 +117,8 @@
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
   [recorder_ horizontalSizeClassDidChange:UIUserInterfaceSizeClassRegular];
 
   histogram_tester_->ExpectUniqueSample(kSizeClassUsedHistogramName,
@@ -128,8 +131,8 @@
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
   [[NSNotificationCenter defaultCenter]
       postNotificationName:UIApplicationDidEnterBackgroundNotification
                     object:nil];
@@ -145,8 +148,8 @@
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
   [[NSNotificationCenter defaultCenter]
       postNotificationName:UIApplicationDidEnterBackgroundNotification
                     object:nil];
@@ -165,8 +168,8 @@
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
   [recorder_
       pageLoadedWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
 
@@ -180,8 +183,8 @@
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
   [recorder_ pageLoadedWithHorizontalSizeClass:UIUserInterfaceSizeClassCompact];
 
   histogram_tester_->ExpectTotalCount(kSizeClassUsedHistogramName, 0);
@@ -194,8 +197,8 @@
   if (!IsIPadIdiom())
     return;
 
-  recorder_.reset([[SizeClassRecorder alloc]
-      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified]);
+  recorder_ = [[SizeClassRecorder alloc]
+      initWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
   [recorder_ pageLoadedWithHorizontalSizeClass:UIUserInterfaceSizeClassRegular];
 
   histogram_tester_->ExpectTotalCount(kSizeClassUsedHistogramName, 0);
diff --git a/ios/chrome/browser/metrics/tab_usage_recorder_unittest.mm b/ios/chrome/browser/metrics/tab_usage_recorder_unittest.mm
index ccd9cd2..ca0817b 100644
--- a/ios/chrome/browser/metrics/tab_usage_recorder_unittest.mm
+++ b/ios/chrome/browser/metrics/tab_usage_recorder_unittest.mm
@@ -4,7 +4,6 @@
 
 #include <memory>
 
-#include "base/mac/scoped_nsobject.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram_samples.h"
 #include "base/stl_util.h"
@@ -20,6 +19,10 @@
 #include "testing/platform_test.h"
 #include "third_party/ocmock/ocmock_extensions.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 @interface TURTestTabMock : OCMockComplexTypeHelper {
   GURL _url;
 }
@@ -105,7 +108,7 @@
     [tab_mock setUrl:webUrl_];
     [[[web_controller_mock stub] andReturnBool:inMemory] isViewAlive];
     [[web_controller_mock stub] removeObserver:OCMOCK_ANY];
-    return [tab_mock autorelease];
+    return tab_mock;
   }
 
   GURL webUrl_;
@@ -312,8 +315,8 @@
   Tab* terminated_tab = MockTab(false);
 
   // Set up the delegate to return |kAliveTabsCountAtRenderTermination|.
-  base::scoped_nsobject<MockTabUsageRecorderDelegate> delegate(
-      [[MockTabUsageRecorderDelegate alloc] init]);
+  MockTabUsageRecorderDelegate* delegate =
+      [[MockTabUsageRecorderDelegate alloc] init];
   [delegate setLiveTabsCount:kAliveTabsCountAtRendererTermination];
   tab_usage_recorder_->SetDelegate(delegate);