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

ios/chrome/browser/memory/memory_debugger.mm

 // Copyright 2014 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/memory/memory_debugger.h"
 
 #include <stdint.h>
 
 #include <memory>
 
-#import "base/mac/scoped_nsobject.h"
 #import "ios/chrome/browser/memory/memory_metrics.h"
 #include "ios/chrome/browser/ui/ui_util.h"
 #import "ios/chrome/browser/ui/uikit_ui_util.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // The number of bytes in a megabyte.
 const CGFloat kNumBytesInMB = 1024 * 1024;
 // The horizontal and vertical padding between subviews.
 const CGFloat kPadding = 10;
 }  // namespace
 
 @implementation MemoryDebugger {
   // A timer to trigger refreshes.
-  base::scoped_nsobject<NSTimer> _refreshTimer;
+  NSTimer* _refreshTimer;
 
   // A timer to trigger continuous memory warnings.
-  base::scoped_nsobject<NSTimer> _memoryWarningTimer;
+  NSTimer* _memoryWarningTimer;
 
   // The font to use.
-  base::scoped_nsobject<UIFont> _font;
+  UIFont* _font;
 
   // Labels for memory metrics.
-  base::scoped_nsobject<UILabel> _physicalFreeMemoryLabel;
-  base::scoped_nsobject<UILabel> _realMemoryUsedLabel;
-  base::scoped_nsobject<UILabel> _xcodeGaugeLabel;
-  base::scoped_nsobject<UILabel> _dirtyVirtualMemoryLabel;
+  UILabel* _physicalFreeMemoryLabel;
+  UILabel* _realMemoryUsedLabel;
+  UILabel* _xcodeGaugeLabel;
+  UILabel* _dirtyVirtualMemoryLabel;
 
   // Inputs for memory commands.
-  base::scoped_nsobject<UITextField> _bloatField;
-  base::scoped_nsobject<UITextField> _refreshField;
-  base::scoped_nsobject<UITextField> _continuousMemoryWarningField;
+  UITextField* _bloatField;
+  UITextField* _refreshField;
+  UITextField* _continuousMemoryWarningField;
 
   // A place to store the artifical memory bloat.
   std::unique_ptr<uint8_t> _bloat;
 
   // Distance the view was pushed up to accomodate the keyboard.
   CGFloat _keyboardOffset;
 
   // The current orientation of the device.
   BOOL _currentOrientation;
 }
 
 - (instancetype)init {
   self = [super initWithFrame:CGRectZero];
   if (self) {
-    _font.reset([[UIFont systemFontOfSize:14] retain]);
+    _font = [UIFont systemFontOfSize:14];
     self.backgroundColor = [UIColor colorWithWhite:0.8f alpha:0.9f];
     self.opaque = NO;
 
     [self addSubviews];
     [self sizeToFit];
     [self registerForNotifications];
   }
   return self;
 }
 
 // NSTimers create a retain cycle so they must be invalidated before this
 // instance can be deallocated.
 - (void)invalidateTimers {
   [_refreshTimer invalidate];
   [_memoryWarningTimer invalidate];
 }
 
 - (void)dealloc {
   [[NSNotificationCenter defaultCenter] removeObserver:self];
-  [super dealloc];
 }
 
 #pragma mark UIView methods
 
 - (CGSize)sizeThatFits:(CGSize)size {
   CGFloat width = 0;
   CGFloat height = 0;
   for (UIView* subview in self.subviews) {
     width = MAX(width, CGRectGetMaxX(subview.frame));
     height = MAX(height, CGRectGetMaxY(subview.frame));
   }
   return CGSizeMake(width + kPadding, height + kPadding);
 }
 
 #pragma mark initialization helpers
 
 - (void)addSubviews {
   // |index| is used to calculate the vertical position of each element in
   // the debugger view.
   NSUInteger index = 0;
 
   // Display some metrics.
-  _physicalFreeMemoryLabel.reset([[UILabel alloc] initWithFrame:CGRectZero]);
+  _physicalFreeMemoryLabel = [[UILabel alloc] initWithFrame:CGRectZero];
   [self addMetricWithName:@"Physical Free"
                   atIndex:index++
                usingLabel:_physicalFreeMemoryLabel];
-  _realMemoryUsedLabel.reset([[UILabel alloc] initWithFrame:CGRectZero]);
+  _realMemoryUsedLabel = [[UILabel alloc] initWithFrame:CGRectZero];
   [self addMetricWithName:@"Real Memory Used"
                   atIndex:index++
                usingLabel:_realMemoryUsedLabel];
-  _xcodeGaugeLabel.reset([[UILabel alloc] initWithFrame:CGRectZero]);
+  _xcodeGaugeLabel = [[UILabel alloc] initWithFrame:CGRectZero];
   [self addMetricWithName:@"Xcode Gauge"
                   atIndex:index++
                usingLabel:_xcodeGaugeLabel];
-  _dirtyVirtualMemoryLabel.reset([[UILabel alloc] initWithFrame:CGRectZero]);
+  _dirtyVirtualMemoryLabel = [[UILabel alloc] initWithFrame:CGRectZero];
   [self addMetricWithName:@"Dirty VM"
                   atIndex:index++
                usingLabel:_dirtyVirtualMemoryLabel];
 
 // Since _performMemoryWarning is a private API it can't be compiled into
 // official builds.
 // TODO(lliabraa): Figure out how to support memory warnings (or something
 // like them) in official builds.
 #if CHROMIUM_BUILD
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wundeclared-selector"
   [self addButtonWithTitle:@"Trigger Memory Warning"
                     target:[UIApplication sharedApplication]
                     action:@selector(_performMemoryWarning)
                 withOrigin:[self originForSubviewAtIndex:index++]];
 #pragma clang diagnostic pop
 #endif  // CHROMIUM_BUILD
 
   // Display a text input to set the amount of artificial memory bloat and a
   // button to reset the bloat to zero.
-  _bloatField.reset([[UITextField alloc] initWithFrame:CGRectZero]);
+  _bloatField = [[UITextField alloc] initWithFrame:CGRectZero];
   [self addLabelWithText:@"Set bloat (MB)"
                    input:_bloatField
              inputTarget:self
              inputAction:@selector(updateBloat)
          buttonWithTitle:@"Clear"
             buttonTarget:self
             buttonAction:@selector(clearBloat)
                  atIndex:index++];
   [_bloatField setText:@"0"];
   [self updateBloat];
 
 // Since _performMemoryWarning is a private API it can't be compiled into
 // official builds.
 // TODO(lliabraa): Figure out how to support memory warnings (or something
 // like them) in official builds.
 #if CHROMIUM_BUILD
   // Display a text input to control the rate of continuous memory warnings.
-  _continuousMemoryWarningField.reset(
-      [[UITextField alloc] initWithFrame:CGRectZero]);
+  _continuousMemoryWarningField =
+      [[UITextField alloc] initWithFrame:CGRectZero];
   [self addLabelWithText:@"Set memory warning interval (secs)"
                    input:_continuousMemoryWarningField
              inputTarget:self
              inputAction:@selector(updateMemoryWarningInterval)
                  atIndex:index++];
   [_continuousMemoryWarningField setText:@"0.0"];
 #endif  // CHROMIUM_BUILD
 
   // Display a text input to control the refresh rate of the memory debugger.
-  _refreshField.reset([[UITextField alloc] initWithFrame:CGRectZero]);
+  _refreshField = [[UITextField alloc] initWithFrame:CGRectZero];
   [self addLabelWithText:@"Set refresh interval (secs)"
                    input:_refreshField
              inputTarget:self
              inputAction:@selector(updateRefreshInterval)
                  atIndex:index++];
   [_refreshField setText:@"0.5"];
   [self updateRefreshInterval];
 }
 
 - (void)registerForNotifications {
@@ skipping 24 matching lines @@
 - (void)addMetricWithName:(NSString*)name
                   atIndex:(NSUInteger)index
                usingLabel:(UILabel*)label {
   // The width of the view for the metric's name.
   const CGFloat kNameWidth = 150;
   // The width of the view for each metric.
   const CGFloat kMetricWidth = 100;
   CGPoint nameOrigin = [self originForSubviewAtIndex:index];
   CGRect nameFrame =
       CGRectMake(nameOrigin.x, nameOrigin.y, kNameWidth, [_font lineHeight]);
-  base::scoped_nsobject<UILabel> nameLabel(
-      [[UILabel alloc] initWithFrame:nameFrame]);
+  UILabel* nameLabel = [[UILabel alloc] initWithFrame:nameFrame];
   [nameLabel setText:[NSString stringWithFormat:@"%@: ", name]];
   [nameLabel setFont:_font];
   [self addSubview:nameLabel];
   label.frame = CGRectMake(CGRectGetMaxX(nameFrame), nameFrame.origin.y,
                            kMetricWidth, [_font lineHeight]);
   [label setFont:_font];
   [label setTextAlignment:NSTextAlignmentRight];
   [self addSubview:label];
 }
 
 // Adds a subview for a button with the given title and target/action.
 - (void)addButtonWithTitle:(NSString*)title
                     target:(id)target
                     action:(SEL)action
                 withOrigin:(CGPoint)origin {
-  base::scoped_nsobject<UIButton> button(
-      [[UIButton buttonWithType:UIButtonTypeSystem] retain]);
+  UIButton* button = [UIButton buttonWithType:UIButtonTypeSystem];
   [button setTitle:title forState:UIControlStateNormal];
   [button titleLabel].font = _font;
   [[button titleLabel] setTextAlignment:NSTextAlignmentCenter];
   [button sizeToFit];
   [button setFrame:CGRectMake(origin.x, origin.y, [button frame].size.width,
                               [_font lineHeight])];
   [button addTarget:target
                 action:action
       forControlEvents:UIControlEventTouchUpInside];
   [self addSubview:button];
@@ skipping 31 matching lines @@
 // The inputTarget/inputAction will be invoked when the user finishes editing
 // in |input|.
 - (void)addLabelWithText:(NSString*)labelText
                    input:(UITextField*)input
              inputTarget:(id)inputTarget
              inputAction:(SEL)inputAction
          buttonWithTitle:(NSString*)buttonTitle
             buttonTarget:(id)buttonTarget
             buttonAction:(SEL)buttonAction
                  atIndex:(NSUInteger)index {
-  base::scoped_nsobject<UILabel> label(
-      [[UILabel alloc] initWithFrame:CGRectZero]);
+  UILabel* label = [[UILabel alloc] initWithFrame:CGRectZero];
   if (labelText) {
     [label setText:[NSString stringWithFormat:@"%@: ", labelText]];
   }
   [label setFont:_font];
   [label sizeToFit];
   CGPoint labelOrigin = [self originForSubviewAtIndex:index];
   [label setFrame:CGRectOffset([label frame], labelOrigin.x, labelOrigin.y)];
   [self addSubview:label];
   if (input) {
     // The width of the views for each input text field.
@@ skipping 171 matching lines @@
     NSString* errorMessage = [NSString
         stringWithFormat:@"Invalid value \"%@\" for refresh interval.\n"
                          @"Must be a positive number.\n" @"Resetting to %.1f",
                          [_refreshField text], refreshTimerValue];
     [self alert:errorMessage];
     [_refreshField
         setText:[NSString stringWithFormat:@"%.1f", refreshTimerValue]];
     return;
   }
   [_refreshTimer invalidate];
-  _refreshTimer.reset(
-      [[NSTimer scheduledTimerWithTimeInterval:refreshTimerValue
-                                        target:self
-                                      selector:@selector(refresh:)
-                                      userInfo:nil
-                                       repeats:YES] retain]);
+  _refreshTimer = [NSTimer scheduledTimerWithTimeInterval:refreshTimerValue
+                                                   target:self
+                                                 selector:@selector(refresh:)
+                                                 userInfo:nil
+                                                  repeats:YES];
 }
 
 #pragma mark Memory warning interval methods
 
 // Since _performMemoryWarning is a private API it can't be compiled into
 // official builds.
 // TODO(lliabraa): Figure out how to support memory warnings (or something
 // like them) in official builds.
 #if CHROMIUM_BUILD
 - (void)updateMemoryWarningInterval {
@@ skipping 16 matching lines @@
                          @"Turning off continuous memory warnings",
                          text];
     [self alert:errorMessage];
     [_continuousMemoryWarningField setText:@""];
     return;
   }
   // If a valid value was found have the timer start triggering continuous
   // memory warnings.
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wundeclared-selector"
-  _memoryWarningTimer.reset(
-      [[NSTimer scheduledTimerWithTimeInterval:timerValue
-                                        target:[UIApplication sharedApplication]
-                                      selector:@selector(_performMemoryWarning)
-                                      userInfo:nil
-                                       repeats:YES] retain]);
+  _memoryWarningTimer =
+      [NSTimer scheduledTimerWithTimeInterval:timerValue
+                                       target:[UIApplication sharedApplication]
+                                     selector:@selector(_performMemoryWarning)
+                                     userInfo:nil
+                                      repeats:YES];
 #pragma clang diagnostic push
 }
 #endif  // CHROMIUM_BUILD
 
 #pragma mark UITextViewDelegate methods
 
 // Dismisses the keyboard if the user hits return.
 - (BOOL)textFieldShouldReturn:(UITextField*)textField {
   [textField resignFirstResponder];
   return YES;
@@ skipping 22 matching lines @@
   [alert addAction:[UIAlertAction actionWithTitle:@"OK"
                                             style:UIAlertActionStyleDefault
                                           handler:nil]];
   [[[[UIApplication sharedApplication] keyWindow] rootViewController]
       presentViewController:alert
                    animated:YES
                  completion:nil];
 }
 
 @end