Gmail talkgadget/hangouts/chat infinite loop

Version: Tor Browser Bundle 3.5.2.1 please relocate to appropriate thread if incorrect

Gmail allows for two types of chat: by default, hangouts, and by choice, legacy chat. These operate in a frame on the lower left of Gmail. Legacy chat works, but reverting to legacy chat from hangouts is impossible from Tor Browser Bundle 3.5.2.1, where an infinite loop interferes.

1. Gmail load attempted with restrictive NoScript settings. Options appear: loosen restrictions, or use HTML only.
2. mail.google.com is whitelisted in NoScript, as well as (optionally) some of the following domains: a. clients6.google.com b. plus.google.com c. talkgadget.google.com d. www.google.com
3. Page is reloaded. The following error message appears in the lower left chat frame: "Something's not right. We're having trouble connecting to Google. We'll keep trying...\n This may be caused by network or proxy issues. Learn more.
4. apis.google.com is whitelisted in NoScript, as recommended on the linked support page. Gmail is refreshed.

Infinite loop:

5. Hangouts loads, with contact list visible. Within seconds, it disappears and is replaced with a Sign In button.
6. The Sign In button is clicked. A pop-up appears with a log-in page from domain accounts.google.com. Password is entered; user signs in. Page declares success, instructs user to close pop-up and refresh Gmail.
7. Go to step 5.

This bug prevents users from being able to use Google chat at all, since reverting to legacy chat requires accessing the main menu in talkgadget/hangouts.

Tried many combinations of NoScript whitelists. None works.