Reland "Typecheck Object.js"

This reverts commit f996a1c537a0722a2601afe8cb5f81f913a02cb0.

Reason for revert: Fixed incorrect refactoring in this CL.

Original change's description:
> Revert "Typecheck Object.js"
>
> This reverts commit 258665aca53731a3d5c15ff624ca3fc743bd33cb.
>
> Reason for revert: Suspected of breaking the roll (https://crrev.com/c/2083712)
> Bot failure: https://ci.chromium.org/p/chromium/builders/try/linux-rel/322462?
>
> Original change's description:
> > Typecheck Object.js
> >
> > To typecheck the file Object.js with Typescript I had to fix the type errors from all other classes
> > that were using addEventListener or removeEventListener incinsistently.
> >
> >
> >
> > Bug: 1011811
> > Change-Id: I2fccbbd07ef3d9a581baa34233580bc6a9dbbfc3
> > Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2079794
> > Reviewed-by: Tim van der Lippe <[email protected]>
> > Reviewed-by: Jack Franklin <[email protected]>
> > Commit-Queue: Jose Leal <[email protected]>
>
> [email protected],[email protected],[email protected],[email protected]
>
> Change-Id: I30e3d75eee463362107d6e6ad25df2b7d50f9d54
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: 1011811
> Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2081824
> Reviewed-by: Simon Zünd <[email protected]>
> Commit-Queue: Simon Zünd <[email protected]>

Bug: 1011811
Change-Id: I19ebbe0345a5c7380ed69d1ba2921adf0385228e
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2084580
Reviewed-by: Simon Zünd <[email protected]>
Commit-Queue: Tim van der Lippe <[email protected]>
diff --git a/front_end/resources/BackgroundServiceView.js b/front_end/resources/BackgroundServiceView.js
index 9401c40..d14821e 100644
--- a/front_end/resources/BackgroundServiceView.js
+++ b/front_end/resources/BackgroundServiceView.js
@@ -117,7 +117,9 @@
     this._toolbar.appendSeparator();
 
     this._saveButton = new UI.Toolbar.ToolbarButton(ls`Save events`, 'largeicon-download');
-    this._saveButton.addEventListener(UI.Toolbar.ToolbarButton.Events.Click, () => this._saveToFile());
+    this._saveButton.addEventListener(UI.Toolbar.ToolbarButton.Events.Click, event => {
+      this._saveToFile();
+    });
     this._saveButton.setEnabled(false);
     this._toolbar.appendToolbarItem(this._saveButton);