Reland of Fix typo in install-sysroot.py (patchset #1 id:1 of https://codereview.chromium.org/1315773003/ )

Reason for revert:
The check_licenses script has been fixed, and it cycled green:
https://build.chromium.org/p/chromium/builders/Linux/builds/66708

Original issue's description:
> Revert of Fix typo in install-sysroot.py (patchset #2 id:20001 of https://codereview.chromium.org/1317973005/ )
>
> Reason for revert:
> Caused check_licenses to fail:
>
> https://build.chromium.org/p/chromium/builders/Linux/builds/66701
>
> Original issue's description:
> > Fix typo in install-sysroot.py
> >
> > install-sysroot.py was intended to default to installing
> > the sysroot ia32, but within this script 'i386' is used to
> > refer to this architecture.
> >
> > This most likely went unnoticed since the ia32 builder
> > either use branding=Official, or explicitly set
> > use_sysroot=1, or have a complete set of packages for
> > cross building on the host system.
> >
> > BUG=504446
> >
> > Committed: https://crrev.com/1d62049b4c176fbd43bed90fc9a76273b11ad406
> > Cr-Commit-Position: refs/heads/master@{#347821}
>
> TBR=dpranke@chromium.org,sbc@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=504446
>
> Committed: https://crrev.com/3b27a2de111759359162bcad49753e17ee1cf002
> Cr-Commit-Position: refs/heads/master@{#347839}

TBR=dpranke@chromium.org,sbc@chromium.org,chrishtr@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=504446

Review URL: https://codereview.chromium.org/1324853005

Cr-Original-Commit-Position: refs/heads/master@{#347901}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 064aca24669857d48458749952a3bc7c9c516e63

linux/sysroot_scripts/install-sysroot.py

@@ -100,7 +100,7 @@ def UsingSysroot(target_arch, gyp_defines):
     return False
 
   # When cross-compiling we always use a sysroot
-  if target_arch in ('arm', 'mips', 'ia32'):
+  if target_arch in ('arm', 'mips', 'i386'):
     return True
 
   # Setting use_sysroot=1 GYP_DEFINES forces the use of the sysroot even