I’ve also encounter this issue when i start implementing custom master page.
Problem: Infinite Looping due to document.documentElement.scrollHeight keep increasing…
Steps to fix this:
1.  Open file core.js
2.  Find

“var lGCWindowHeight=document.documentElement.scrollHeight;”

3.  Replace it with:

“var lGCWindowHeight=(document.documentElement.scrollHeight>document.documentElement.clientHeight) ? document.documentElement.clientHeight : document.documentElement.scrollHeight;”

4. Bingo, problem solved!