Adding AIX

Change-Id: Ibf023a1f6b635872c849bda885b47ea1dbf7dda3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2410733
Reviewed-by: Dirk Pranke <dpranke@google.com>
Commit-Queue: Dirk Pranke <dpranke@google.com>
diff --git a/gclient_utils.py b/gclient_utils.py
index 6820a19..21401de 100644
--- a/gclient_utils.py
+++ b/gclient_utils.py
@@ -589,7 +589,7 @@
     # If our stdout is a terminal, then pass in a psuedo-tty pipe to our
     # subprocess when filtering its output. This makes the subproc believe
     # it was launched from a terminal, which will preserve ANSI color codes.
-    if sys.stdout.isatty() and GetMacWinOrLinux() != 'win':
+    if sys.stdout.isatty() and GetMacWinAixOrLinux() != 'win':
       pipe_reader, pipe_writer = os.openpty()
     else:
       pipe_reader, pipe_writer = os.pipe()
@@ -737,7 +737,7 @@
     path = new_path
 
 
-def GetMacWinOrLinux():
+def GetMacWinAixOrLinux():
   """Returns 'mac', 'win', or 'linux', matching the current platform."""
   if sys.platform.startswith(('cygwin', 'win')):
     return 'win'
@@ -745,6 +745,8 @@
     return 'linux'
   elif sys.platform == 'darwin':
     return 'mac'
+  elif sys.platform.startswith('aix'):
+    return 'aix'
   raise Error('Unknown platform: ' + sys.platform)