[Reland] Enable AutoResize for Constrained Web Dialogs for Mac.

chrome/browser/ui/cocoa/autofill/autofill_dialog_cocoa.mm

Index: chrome/browser/ui/cocoa/autofill/autofill_dialog_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/autofill/autofill_dialog_cocoa.mm b/chrome/browser/ui/cocoa/autofill/autofill_dialog_cocoa.mm
index 4a80bbde542f95c97c96a67acf5fe63f554e3ff2..99a645fe6bda7e000f020e229febb8dc069af4d5 100644
--- a/chrome/browser/ui/cocoa/autofill/autofill_dialog_cocoa.mm
+++ b/chrome/browser/ui/cocoa/autofill/autofill_dialog_cocoa.mm
@@ -39,7 +39,7 @@ void AutofillDialogCocoa::Show() {
       [[CustomConstrainedWindowSheet alloc]
           initWithCustomWindow:[sheet_delegate_ window]]);
   constrained_window_.reset(
-      new ConstrainedWindowMac(this, delegate_->GetWebContents(), sheet));
+      CreateAndShowWebModalDialogMac(this, delegate_->GetWebContents(), sheet));
   [sheet_delegate_ show];
 }