Revert of Re-land: 178586 Avoid fragmenting address space on small windows systems. (patchset #3 id:40001 of https://codereview.chromium.org/717263005/)
Revert of Re-land: 178586 Avoid fragmenting address space on small windows systems. (patchset #3 id:40001 of https://codereview.chromium.org/717263005/)

Reason for revert:
This CL crashed all layout tests on XP bot.

Original issue's description:
> Re-land: 178586 Avoid fragmenting address space on small windows systems.
> 
> The concern about IsWow64Process() is not founded per jschuh@ (but the effect of
> changing the allocator behaviour may be). We now have a clean baseline to test
> against.
> 
> R=cevans@chromium.org
> BUG=394591
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=185559

TBR=cevans@chromium.org,tsepez@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=394591

Review URL: https://codereview.chromium.org/806683003

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@187141 bbb929c8-8fbe-4397-9dbb-9b2b20218538

jtg-gg/blink,Bysmyyr/blink-crosswalk,kurli/blink-crosswalk,Pluto-tv/blink-crosswalk,Bysmyyr/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,smishenk/blink-crosswalk,smishenk/blink-crosswalk,PeterWangIntel/blink-crosswalk,PeterWangIntel/blink-crosswalk,kurli/blink-crosswalk,Bysmyyr/blink-crosswalk,jtg-gg/blink,modulexcite/blink,Pluto-tv/blink-crosswalk,kurli/blink-crosswalk,PeterWangIntel/blink-crosswalk,Pluto-tv/blink-crosswalk,PeterWangIntel/blink-crosswalk,smishenk/blink-crosswalk,XiaosongWei/blink-crosswalk,nwjs/blink,Bysmyyr/blink-crosswalk,PeterWangIntel/blink-crosswalk,smishenk/blink-crosswalk,smishenk/blink-crosswalk,XiaosongWei/blink-crosswalk,Bysmyyr/blink-crosswalk,modulexcite/blink,kurli/blink-crosswalk,kurli/blink-crosswalk,Bysmyyr/blink-crosswalk,XiaosongWei/blink-crosswalk,XiaosongWei/blink-crosswalk,modulexcite/blink,jtg-gg/blink,nwjs/blink,XiaosongWei/blink-crosswalk,kurli/blink-crosswalk,smishenk/blink-crosswalk,nwjs/blink,kurli/blink-crosswalk,XiaosongWei/blink-crosswalk,XiaosongWei/blink-crosswalk,smishenk/blink-crosswalk,kurli/blink-crosswalk,Pluto-tv/blink-crosswalk,nwjs/blink,smishenk/blink-crosswalk,modulexcite/blink,nwjs/blink,nwjs/blink,Pluto-tv/blink-crosswalk,modulexcite/blink,kurli/blink-crosswalk,PeterWangIntel/blink-crosswalk,jtg-gg/blink,PeterWangIntel/blink-crosswalk,modulexcite/blink,nwjs/blink,jtg-gg/blink,jtg-gg/blink,modulexcite/blink,PeterWangIntel/blink-crosswalk,jtg-gg/blink,XiaosongWei/blink-crosswalk,Bysmyyr/blink-crosswalk,modulexcite/blink,smishenk/blink-crosswalk,XiaosongWei/blink-crosswalk,nwjs/blink,modulexcite/blink,jtg-gg/blink,Bysmyyr/blink-crosswalk,Bysmyyr/blink-crosswalk,smishenk/blink-crosswalk,Bysmyyr/blink-crosswalk,kurli/blink-crosswalk,jtg-gg/blink,Pluto-tv/blink-crosswalk,PeterWangIntel/blink-crosswalk,nwjs/blink,Pluto-tv/blink-crosswalk,PeterWangIntel/blink-crosswalk,jtg-gg/blink,nwjs/blink,modulexcite/blink,XiaosongWei/blink-crosswalk