1765966 - don't call CalculateScrollableRectForFrame in UpdateCompositionBoundsForRCDRSF if we don't need to

Status: RESOLVED FIXED

(Core :: Layout: Scrolling and Overflow, task)

Description

[Timothy Nikkel (:tnikkel)]

https://phabricator.services.mozilla.com/D144415#4719328

Comment 1

[Timothy Nikkel (:tnikkel)]

Attachment: Bug 1765966. Don't call CalculateScrollableRectForFrame in UpdateCompositionBoundsForRCDRSF if we don't need to. r?emilio,hiro

We only use the value to modify shouldSubtractDynamicToolbar and we only use that with a dynamic toolbar.

This saves us some time and also prevents a circular dependency when reflowing a scroll frame. nsHTMLScrollFrame::TryLayout calls nsLayoutUtils::CalculateCompositionSizeForFrame

https://searchfox.org/mozilla-central/rev/6da1ebe13b260efabd88eb98dec5fa8ee65987b2/layout/generic/nsGfxScrollFrame.cpp#616

and then nsLayoutUtils::UpdateCompositionBoundsForRCDRSF calls GetScrolledRect, but reflow can determine the scrolled rect (presence/absence of scrollbars affect it for example).

But this also prevents us from hitting the warning of bug 1695139 in the case of a google search results page as one example, because we are getting the scrolled rect while we might be in an inconsistent state during reflow.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/4dfec522e1eb
Don't call CalculateScrollableRectForFrame in UpdateCompositionBoundsForRCDRSF if we don't need to. r=emilio

Comment 3

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/4dfec522e1eb