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

ios/chrome/browser/ui/toolbar/web_toolbar_controller.h

Index: ios/chrome/browser/ui/toolbar/web_toolbar_controller.h
diff --git a/ios/chrome/browser/ui/toolbar/web_toolbar_controller.h b/ios/chrome/browser/ui/toolbar/web_toolbar_controller.h
index 62d66196b9c10841f474a07eda6834c35ff92596..060a54e12640bead7ca5a3b4131a9d36d816be5e 100644
--- a/ios/chrome/browser/ui/toolbar/web_toolbar_controller.h
+++ b/ios/chrome/browser/ui/toolbar/web_toolbar_controller.h
@@ -87,8 +87,8 @@ extern const CGFloat kiPhoneOmniboxPlaceholderColorBrightness;
                         QRScannerViewControllerDelegate,
                         VoiceSearchControllerDelegate>
 
-@property(nonatomic, assign) id<WebToolbarDelegate> delegate;
-@property(nonatomic, assign, readonly) id<UrlLoader> urlLoader;
+@property(nonatomic, weak) id<WebToolbarDelegate> delegate;
+@property(nonatomic, weak, readonly) id<UrlLoader> urlLoader;
 
 // Mark inherited initializer as unavailable.
 - (instancetype)initWithStyle:(ToolbarControllerStyle)style NS_UNAVAILABLE;