[ObjC ARC] Converts ios/chrome/browser/ui/history:history to ARC.

ios/chrome/browser/ui/history/tab_history_view_controller.mm

Index: ios/chrome/browser/ui/history/tab_history_view_controller.mm
diff --git a/ios/chrome/browser/ui/history/tab_history_view_controller.mm b/ios/chrome/browser/ui/history/tab_history_view_controller.mm
index fcd1f851ac8422802ef7391d424df8895552f743..915e95ebb19035c3f0c5b82c334285ebc4112e33 100644
--- a/ios/chrome/browser/ui/history/tab_history_view_controller.mm
+++ b/ios/chrome/browser/ui/history/tab_history_view_controller.mm
@@ -7,7 +7,6 @@
 #import "base/ios/weak_nsobject.h"
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
-#include "base/mac/objc_property_releaser.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 #import "ios/chrome/browser/ui/commands/UIKit+ChromeExecuteCommand.h"
@@ -20,6 +19,10 @@
 #include "ios/web/public/navigation_item.h"
 #include "ui/gfx/image/image.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 // Visible percentage of the last visible row on the Tools menu if the
@@ -226,7 +229,7 @@ layoutAttributesForSupplementaryViewOfKind:(NSString*)kind
 @implementation TabHistoryViewController
 
 - (NSArray*)sessionEntries {
-  return [[_sessionEntries retain] autorelease];
+  return _sessionEntries;
 }
 
 #pragma mark Public Methods
@@ -370,7 +373,7 @@ layoutAttributesForSupplementaryViewOfKind:(NSString*)kind
 }
 
 - (void)setSessionEntries:(NSArray*)sessionEntries {
-  _sessionEntries.reset([sessionEntries retain]);
+  _sessionEntries.reset(sessionEntries);
 
   std::string previousHost;
 
@@ -406,7 +409,7 @@ layoutAttributesForSupplementaryViewOfKind:(NSString*)kind
   if (![partitionedEntries count])
     partitionedEntries = nil;
 
-  _partitionedEntries.reset([partitionedEntries retain]);
+  _partitionedEntries.reset(partitionedEntries);
 }
 
 #pragma mark MDCInkTouchControllerDelegate