UserAgent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:62.0) Gecko/20100101 Firefox/62.0

Steps to reproduce the problem:
Product affected:
OS              Linux
Chromium	68.0.3440.106 (Official Build) (64-bit)
Revision	1c32c539ce0065a41cb79da7bfcd2c71af1afe62-refs/branch-heads/3440@{#794}
JavaScript	V8 6.8.275.26

Steps to reproduce:
1. Open poc.html
2. Wait for a while
3. You see snap page!

In debug mode the below JS stack was generated.

<--- JS stacktrace --->

==== JS stack trace =========================================

    0: ExitFrame [pc: 0x3560c1f5c33d]
    1: StubFrame [pc: 0x3560c1f5d6ff]
Security context: 0x09f3d4907499 <Window map = 0xff155b02259>
    2: /* anonymous */ [0x9f3d497ebe1] [file:///home/input0/Desktop/1.html:~3] [pc=0x3560c1fc96b4](this=0x1cb6add07f51 <JSGlobal Object>)
    3: InternalFrame [pc: 0x3560c1f0eed5]
    4: EntryFrame [pc: 0x3560c1f059a1]

==== Details ================================================

[0]: ExitFrame [pc: 0...

What is the expected behavior?

What went wrong?
poc.html

<script>
var a = '';
for (var i = 1; i <= 500000000000; i++)
{
  a += '\n';
}
alert(a);
</script>

Did this work before? No 

Chrome version: 68.0.3440.106 (Official Build) (64-bit)  Channel: n/a
OS Version: 
Flash Version: Shockwave Flash 30.0 r0