Memory leak: a lot of private strings (New Identity doesn't help)
Add-on eats memory (measured after New Identity):
396.83 MB (100.0%) -- explicit
├──338.72 MB (85.36%) -- js-non-window
│ ├──213.99 MB (53.92%) -- zones
│ │ ├──201.19 MB (50.70%) -- zone(0x5644a80)
│ │ │ ├───44.10 MB (11.11%) -- strings
│ │ │ │ ├──25.50 MB (06.43%) -- (276 tiny)
│ │ │ │ │ ├───1.32 MB (00.33%) ++ string(length=65, copies=16827, "Mozilla/5.0 (Windows NT 6.1; rv:45.0) Gecko/20100101 Firefox/45.0")
│ │ │ │ │ ├───1.01 MB (00.25%) ── string(length=8, copies=33147, "HTTP/1.1")/gc-heap/latin1
│ │ │ │ │ ├───0.82 MB (00.21%) ++ string(length=4112, copies=207, "Bugzilla_login_request_cookie=BFcSJVoFrY; github_secret=BfpXCUcCE5t1S3Z9; LASTORDER=bug_status%2Cpriority%2Cassigned_to%2Cbug_id;" (truncated))
│ │ │ │ │ ├───0.75 MB (00.19%) ── string(length=15, copies=24533, "Accept-Encoding")/gc-heap/latin1
│ │ │ │ │ ├───0.72 MB (00.18%) ++ string(length=37, copies=14052, "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256")
│ │ │ │ │ ├───0.71 MB (00.18%) ── string(length=10, copies=23350, "Connection")/gc-heap/latin1
│ │ │ │ │ ├───0.67 MB (00.17%) ++ string(length=84, copies=6938, "trac_form_token=fd9d72f5b4cd93e1480c148c; trac_auth=5600191927c0d02b1262131d6ee91acd")
│ │ │ │ │ ├───0.41 MB (00.10%) ++ string(length=25, copies=10285, "Strict-Transport-Security")
│ │ │ │ │ ├───0.37 MB (00.09%) ++ string(length=19, copies=16351, "trac.torproject.org")/gc-heap
│ │ │ │ │ ├───0.28 MB (00.07%) ++ string(length=595, copies=486, "yandex_login=bugzilla; stngs=colorful::on:")
And many many others...