Don't import win32gui when it's not needed

chrome/test/data/native_messaging/native_hosts/echo.py

Index: chrome/test/data/native_messaging/native_hosts/echo.py
diff --git a/chrome/test/data/native_messaging/native_hosts/echo.py b/chrome/test/data/native_messaging/native_hosts/echo.py
index 0af7f73fd15cada85974685ef2950f25e082cbb5..33aa789f8253c72a06c59823fd9d40ccf2e3c1ae 100755
--- a/chrome/test/data/native_messaging/native_hosts/echo.py
+++ b/chrome/test/data/native_messaging/native_hosts/echo.py
@@ -38,9 +38,9 @@ def Main():
     elif caller_url == None:
       caller_url = arg
 
-  if platform.system() == 'Windows':
+  if platform.system() == 'Windows' and parent_window:
     import win32gui
-    if parent_window and not win32gui.IsWindow(parent_window):
+    if not win32gui.IsWindow(parent_window):
       sys.stderr.write('Invalid --parent-window.\n')
       return 1