Pass handle of the native view window to the native messaging host.

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 a4471c7cbb4d4fe96037b3ebb7887215850dd5b7..e9550f6cf678f7831b2617c03b3e39f23a6f7dfe 100755
--- a/chrome/test/data/native_messaging/native_hosts/echo.py
+++ b/chrome/test/data/native_messaging/native_hosts/echo.py
@@ -25,7 +25,10 @@ def Main():
   if len(sys.argv) < 2:
     sys.stderr.write("URL of the calling application is not specified.\n")
     return;
-  caller_url = sys.argv[1]
+  for arg in sys.argv[1:]:
+    if not arg.startswith('--'):
+      caller_url = arg
+      break
 
   while 1:
     # Read the message type (first 4 bytes).