[iOS] Break retain cycle in InfoBars.

ios/chrome/browser/passwords/update_password_infobar_controller.mm

Index: ios/chrome/browser/passwords/update_password_infobar_controller.mm
diff --git a/ios/chrome/browser/passwords/update_password_infobar_controller.mm b/ios/chrome/browser/passwords/update_password_infobar_controller.mm
index 656b3bb2f88bf4630890b2e793e8359657edceeb..102624fb6c70d87ae2db4d3ae05b50c502970413 100644
--- a/ios/chrome/browser/passwords/update_password_infobar_controller.mm
+++ b/ios/chrome/browser/passwords/update_password_infobar_controller.mm
@@ -4,6 +4,7 @@
 
 #import "ios/chrome/browser/passwords/update_password_infobar_controller.h"
 
+#include "base/ios/weak_nsobject.h"
 #import "base/mac/objc_property_releaser.h"
 #include "base/strings/string_util.h"
 #include "base/strings/sys_string_conversions.h"
@@ -61,9 +62,12 @@ - (void)updateInfobarLabel:(InfoBarView*)view {
         &messageText, 0, _delegate->selected_account(), usernameLink);
   }
 
+  base::WeakNSObject<UpdatePasswordInfoBarController> weakSelf(self);
   [view addLabel:base::SysUTF16ToNSString(messageText)
           action:^(NSUInteger tag) {
-            [self infobarLinkDidPress:tag];
+            base::scoped_nsobject<BeforeTranslateInfoBarController> strongSelf(

[sdefresne, 2017/06/12 14:14:24]

nit: I think it is okay to do the following

  [weakSelf infoBarLinkDidPress:tag];

+                [weakSelf retain]);
+            [strongSelf infobarLinkDidPress:tag];
           }];
 }