Chrome Version: 59.0.3071.115
OS: Linux

What steps will reproduce the problem?
(1) Find a page with an embedded plugin (e.g. PDF: https://msu.edu/~urban/sme865/resources/embedded_pdf.html) 
(2) Using console add a dragleave event handler to the body inside the guest process:
document.body.addEventListener('dragleave', () => { console.log("BODY leave");})
(3) Drag the URL from the omnibox into the plugin

What is the expected result?
The body should receive a `dragleave` event and so "BODY leave" should be printed to the console.

What happens instead?
Nothing

Note that dropping text or other types of objects does fire the dragleave event.