-e: see title

-repro:
--Create New Unity 5.1.0f2 project & empty scene
--Build and run as WebGL
--Copy t <http://localhost:50380/>he local host address E.g. --http://localhost:50380/ <http://localhost:50380/> from the browser address bar
--navigate somewhere else to create a navigation history and enable the back button (E.g. google.com)
--paste back in your localhost address
--Press backspace when you see the blue skybox
--App/Browser attempts to navigate backwards (this never used to happen in previous builds and makes text entry/editing impossible)
--NOTICE App crashes in the middle of handling the keyboard event