WebUI: prevent WebContent to hold an invalid pointer.

chrome/browser/ui/views/constrained_web_dialog_delegate_views.cc

Index: chrome/browser/ui/views/constrained_web_dialog_delegate_views.cc
diff --git a/chrome/browser/ui/views/constrained_web_dialog_delegate_views.cc b/chrome/browser/ui/views/constrained_web_dialog_delegate_views.cc
index 57fefa85d47a93229320c9ecb890f33807bad225..2a81de25a633df5a03ca22084d3a9e3da603d6ef 100644
--- a/chrome/browser/ui/views/constrained_web_dialog_delegate_views.cc
+++ b/chrome/browser/ui/views/constrained_web_dialog_delegate_views.cc
@@ -175,8 +175,8 @@ class ConstrainedWebDialogDelegateViewViews
   void OnDialogCloseFromWebUI() override {
     return impl_->OnDialogCloseFromWebUI();
   }
-  void ReleaseWebContentsOnDialogClose() override {
-    return impl_->ReleaseWebContentsOnDialogClose();
+  std::unique_ptr<content::WebContents> ReleaseWebContents() override {
+    return impl_->ReleaseWebContents();
   }
   gfx::NativeWindow GetNativeDialog() override {
     return impl_->GetNativeDialog();