Always add braces to single-line if-statements

The Chromium/Google style guides does not enforce curly braces for
single-line if-statements, but does strongly recommend doing so. Adding
braces will improve code readability, by visually separating code
blocks. This will also prevent issues where accidental additions are
pushed to the "else"-clause instead of in the if-block.

This CL also updates the presubmit `eslint` to run the fix with the
correct configuration. It will now fix all issues it can fix.

Change-Id: I4b616f21a99393f168dec743c0bcbdc7f5db04a9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1821526
Commit-Queue: Tim Van der Lippe <[email protected]>
Reviewed-by: Yang Guo <[email protected]>
Reviewed-by: Jeff Fisher <[email protected]>
Cr-Original-Commit-Position: refs/heads/master@{#701070}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 7e0bdbe2d7f9fc2386bfaefda3cc29c66ccc18f9
diff --git a/front_end/ui/Panel.js b/front_end/ui/Panel.js
index 30f0ad3..5bcacc0 100644
--- a/front_end/ui/Panel.js
+++ b/front_end/ui/Panel.js
@@ -71,10 +71,11 @@
    */
   showInfobar(infobar) {
     infobar.setCloseCallback(this._onInfobarClosed.bind(this, infobar));
-    if (this.element.firstChild)
+    if (this.element.firstChild) {
       this.element.insertBefore(infobar.element, this.element.firstChild);
-    else
+    } else {
       this.element.appendChild(infobar.element);
+    }
     infobar.setParentView(this);
     this.doResize();
   }