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

ios/chrome/browser/physical_web/physical_web_initial_state_recorder.mm

Index: ios/chrome/browser/physical_web/physical_web_initial_state_recorder.mm
diff --git a/ios/chrome/browser/physical_web/physical_web_initial_state_recorder.mm b/ios/chrome/browser/physical_web/physical_web_initial_state_recorder.mm
index a05bbb414f8993d00dd73ac647b03853294b54f3..56528cada54e2c24d39f6fbc482aae2b5d2b4953 100644
--- a/ios/chrome/browser/physical_web/physical_web_initial_state_recorder.mm
+++ b/ios/chrome/browser/physical_web/physical_web_initial_state_recorder.mm
@@ -7,12 +7,15 @@
 #import <CoreBluetooth/CoreBluetooth.h>
 #import <CoreLocation/CoreLocation.h>
 
-#include "base/mac/scoped_nsobject.h"
 #include "base/metrics/histogram_macros.h"
 #include "components/prefs/pref_service.h"
 #include "ios/chrome/browser/physical_web/physical_web_constants.h"
 #include "ios/chrome/browser/pref_names.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 const double kStartupDelaySeconds = 10.0;
@@ -62,8 +65,8 @@ enum PhysicalWebInitialStateIosChrome {
 @implementation PhysicalWebInitialStateRecorder {
   int preferenceState_;
   BOOL recordedState_;
-  base::scoped_nsobject<NSTimer> startupDelayTimer_;
-  base::scoped_nsobject<CBCentralManager> centralManager_;
+  NSTimer* startupDelayTimer_;
+  CBCentralManager* centralManager_;
 }
 
 - (instancetype)initWithPrefService:(PrefService*)prefService {
@@ -81,21 +84,20 @@ enum PhysicalWebInitialStateIosChrome {
 
 - (void)dealloc {
   [self invalidate];
-  [super dealloc];
 }
 
 - (void)invalidate {
-  if (startupDelayTimer_.get()) {
+  if (startupDelayTimer_) {
     [startupDelayTimer_ invalidate];
-    startupDelayTimer_.reset();
+    startupDelayTimer_ = nil;
   }
   [centralManager_ setDelegate:nil];
-  centralManager_.reset();
+  centralManager_ = nil;
 }
 
 - (void)centralManagerDidUpdateState:(CBCentralManager*)central {
   [centralManager_ setDelegate:nil];
-  centralManager_.reset();
+  centralManager_ = nil;
 
   BOOL bluetoothEnabled = [centralManager_ state] == CBManagerStatePoweredOn;
 
@@ -117,20 +119,20 @@ enum PhysicalWebInitialStateIosChrome {
     return;
   }
   recordedState_ = YES;
-  startupDelayTimer_.reset(
-      [[NSTimer scheduledTimerWithTimeInterval:kStartupDelaySeconds
-                                        target:self
-                                      selector:@selector(startupDelayElapsed:)
-                                      userInfo:nil
-                                       repeats:NO] retain]);
+  startupDelayTimer_ =
+      [NSTimer scheduledTimerWithTimeInterval:kStartupDelaySeconds
+                                       target:self
+                                     selector:@selector(startupDelayElapsed:)
+                                     userInfo:nil
+                                      repeats:NO];
 }
 
 - (void)startupDelayElapsed:(NSTimer*)timer {
-  startupDelayTimer_.reset();
+  startupDelayTimer_ = nil;
 
   // The Bluetooth enabled state must be checked asynchronously. When the state
   // is ready, it will call our centralManagerDidUpdateState method.
-  centralManager_.reset([[CBCentralManager alloc]
+  centralManager_ = [[CBCentralManager alloc]
       initWithDelegate:self
                  queue:dispatch_get_main_queue()
                options:@{
@@ -139,7 +141,7 @@ enum PhysicalWebInitialStateIosChrome {
                  // Passing ShowPowerAlert=NO disables the prompt so we can
                  // check the Bluetooth enabled state silently.
                  CBCentralManagerOptionShowPowerAlertKey : @NO
-               }]);
+               }];
 }
 
 - (void)recordStateWithPreferenceState:(int)preferenceState