This change renames TabContext::IsBrowserElement to IsIsolatedMozBrowserElement.
Other methods that pass these values around also have name changes.
Adds TabContext::IsMozBrowserElement which is set by the frame loader for all
browser frames. This is in contrast to its previous implementation, which has
since been renamed IsIsolatedMozBrowserElement, since it checks isolated state
in OriginAttributes.
TabContext methods related to browser elements (and their callers) are updated
to use IsIsolatedMozBrowserElement when check isolation / origins and
IsMozBrowserElement when checking frame types.
MozReview-Commit-ID: DDMZTkSn5yd
The ScrollingBehavior passed around extensively in TabParent/TabChild is
entirely redundant now that the layers.async-pan-zoom.enabled pref definitively
controls whether or not APZ is enabled. All the code related to ScrollingBehavior
can be removed.
