Bug: Mobile web agent interface doesn't handle swipe left to close sidebar

Hi folks, low-priority UI bug.

Environment: Chrome 52.0.2743.98 on Android 5.1.

Steps:

1. Open agent interface
2. Press <hamburger button> in upper left to reveal sidebar
3. Swipe main pane to the left

Result is an overlaid sidebar with main pane. Screenshot:

Recovery: Pressing the <hamburger button> again correctly closes sidebar.

Workaround: Always use <hamburger button> to close the sidebar. Never attempt to swipe the main pane back to the left.

Reproducibility: 100%. Many attempts.

Thanks!