Hey There,
I'd do the heavy lifting more directly with the shell or with AppleScript.
###AppleScript:
set gmailURL to "https://mail.google.com/mail/u/0/?ui=2&view=cm&fs=1&tf=1&shva=1"
tell application "Google Chrome"
activate
set newWin to make new window with properties {bounds:{0, 22, 1040, 1196}}
tell newWin
set URL of active tab to gmailURL
end tell
end tell
The shell script will be a little more bombproof; the AppleScript a little more versatile.
The AppleScript might time-out if Chrome took a long time to launch, but that can be worked around in the script of course.
-Chris