UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36

Steps to reproduce the problem:
1. Create a popup for a chrome extension which includes a css file which defines a custom keyframes value:

@keyframes spinner {
    to {
        transform: rotate(1turn);
    }
}

2. use this keyframes animation on one of your nodes:

animation: spinner 700ms infinite linear;

3. try opening the popup afterwards, sometimes it FAILS to render to a correct size and is forced to a minimum (like 20x30 pixels)

What is the expected behavior?
The popup should always open with the correct size... the complete content of the popup html file.

What went wrong?
The resizing seems to be broken when keyframes are used.

Did this work before? N/A 

Does this work in other browsers? Yes

Chrome version: 56.0.2924.87  Channel: stable
OS Version: OS X 10.12.2
Flash Version: Shockwave Flash 24.0 r0