Chrome Extension: Unsafe JavaScript attempt to access frame with URL Domains, protocols and ports must match
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This answer specifies explains how to access the content of all iframes on gmail.com http://stackoverflow.com/a/9439525/222236

But on mail.google.com it throws this error:

Unsafe JavaScript attempt to access frame with URL https://plus.google.com/u/0/_/... from frame with URL https://mail.google.com/mail/u/0/#inbox. Domains, protocols and ports must match.

I tried adding "*://plus.google.com/*" to the matches of the manifest of the extension, but it didn't help.


