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

ios/chrome/browser/ui/reader_mode/reader_mode_view.h

 // 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.
 
 #ifndef IOS_CHROME_BROWSER_UI_READER_MODE_READER_MODE_VIEW_H_
 #define IOS_CHROME_BROWSER_UI_READER_MODE_READER_MODE_VIEW_H_
 
 #import <UIKit/UIKit.h>
 
 #include <memory>
@@ skipping 17 matching lines @@
 @interface ReaderModeView : UIView
 
 - (instancetype)initWithFrame:(CGRect)frame
                      delegate:(id<ReaderModeViewDelegate>)delegate
     NS_DESIGNATED_INITIALIZER;
 
 - (instancetype)initWithFrame:(CGRect)frame NS_UNAVAILABLE;
 - (instancetype)initWithCoder:(NSCoder*)aDecoder NS_UNAVAILABLE;
 
 // The view's delegate.
-@property(nonatomic, readonly) id<ReaderModeViewDelegate> delegate;
+@property(weak, nonatomic, readonly) id<ReaderModeViewDelegate> delegate;
 
 // Takes ownership of the viewer as it is the only handle to the distillation:
 // When freed it cancels the distillation, if it is not finished yet. The
 // ReaderModeView instance owns this object so that the distillation is
 // cancelled if the view is deallocated.
 - (void)assignDistillerViewer:
     (std::unique_ptr<dom_distiller::DistillerViewer>)viewer;
 
 // Starts the waiting animation.
 - (void)start;
 
 // Call this method when this view is removed from the visible view hierarchy.
 // |completion| will be called when this view is done animating out.
 - (void)stopWaitingWithCompletion:(ProceduralBlock)completion;
 
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_READER_MODE_READER_MODE_VIEW_H_