Capabilities are currently sent to the content frame script when its IPC message listeners attach (on Marionette:ListenersAttached). If for whatever reason a capability's value changes since the script was registered, for example by a user calling the WebDriver:SetTimeouts command, a race condition is introduced where the capabilities in chrome will differ from those cached in the frame script. To remove any chance of race conditions, this patch changes the content frame script to query the capabilities from chrome every time it needs them. This is slightly less efficient, but should be neglible. The patch also clears up some unused state, such as the curBrowser.newSessionCommandId property, which did not appear to be used for anything interesting. Review commit: https://reviewboard.mozilla.org/r/209738/diff/#index_header See other reviews: https://reviewboard.mozilla.org/r/209738/

Comment on attachment 8939367 [details] Bug 1379490 - Query capabilities configuration from chrome. Review request updated; see interdiff: https://reviewboard.mozilla.org/r/209738/diff/1-2/