It looks like TabChild::RenderLayers already does the work of suppressing the displayport,
so all of the suppression and bookkeeping that AsyncTabSwitcher is doing is superfluous
and probably opening us up to weird graphical glitches (like the one associated with this
bug).
MozReview-Commit-ID: 5qIVguSMsnr
It looks like TabChild::RenderLayers already does the work of suppressing the displayport,
so all of the suppression and bookkeeping that AsyncTabSwitcher is doing is superfluous
and probably opening us up to weird graphical glitches (like the one associated with this
bug).
MozReview-Commit-ID: 5qIVguSMsnr
We suppress the displayport when requesting a tab or warming it, in order to reduce
the amount of work that the content process needs to do to paint it (we paint just
the displayport area and nothing around it). Afterwards, we unsuppress the displayport
so that we can paint the surrounding areas when scrolling. We normally do this
unsuppression in destroy(), but with tab warming, that unsuppression can happen
after a few seconds (after the tab warming eviction timeout).
This results in users seeing checkerboarding sometimes, where the tab they're looking
at is still suppressing its displayport and waiting for the timeout to complete.
This patch updates the AsyncTabSwitcher to unsuppress the displayport for a tab as
soon as the tab has been switched to, instead of waiting for the timeout.
Out of an abundance of caution, we still unsuppress displayports for tabs that
never get to enter the STATE_LOADED state, although that really should never
happen.
MozReview-Commit-ID: 5qIVguSMsnr
Since bug 1432509, the warmingTabs WeakSet has had warmed tabs
cleared from it once they have entered STATE_LOADED. This allowed
us to make decisions on tab switch operations based on whether or
not a tab was still being warmed.
This broke our Telemetry, which assumed that warming tabs would
still be in the warmingTabs WeakSet until either requested or
evicted. Now, instead, we look to see whether or not tab warming
is enabled, and whether tabs _could_ have been warmed in order to
add entries to the right buckets.
MozReview-Commit-ID: 94oiKYzf4au
