tree f68706ab1cbefd32ae1d0ecef0b2694dc521a6c0
parent e720e798e1db9fc9257fdd931b3a3902775c4fbe
author simon.fraser@apple.com <simon.fraser@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1557975075 +0000
committer simon.fraser@apple.com <simon.fraser@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1557975075 +0000

Clean up RenderLayerCompositor::computeCompositingRequirements() and traverseUnchangedSubtree()
https://bugs.webkit.org/show_bug.cgi?id=197931

Reviewed by Zalan Bujtas.

These functions have grown and become hard to maintain, so try to undo some technical debt.

Rename "childState" to "currentState" since it's the state we pass to children, but also
is state we change when the current layer becomes composited.

Separate the layerWillComposite() lambda from layerWillCompositePostDescendants().

Group the chunks of code at end of the functions into:
    - updating bits on RenderLayer
    - updating compositingState with changes from children and our state
    - doing post-traversal work on overlapMap and backingSharingState

Code shared between the two functions is pushed into CompositingState::updateWithDescendantStateAndLayer().

This moves code around but should not cause any behavior change.

* rendering/RenderLayerBacking.cpp:
(WebCore::RenderLayerBacking::updateConfiguration):
* rendering/RenderLayerCompositor.cpp:
(WebCore::RenderLayerCompositor::OverlapExtent::knownToBeHaveExtentUncertainty const):
(WebCore::RenderLayerCompositor::CompositingState::updateWithDescendantStateAndLayer):
(WebCore::RenderLayerCompositor::computeCompositingRequirements):
(WebCore::RenderLayerCompositor::traverseUnchangedSubtree):
(WebCore::RenderLayerCompositor::clipsCompositingDescendants):
(WebCore::RenderLayerCompositor::CompositingState::propagateStateFromChildren): Deleted.
(WebCore::RenderLayerCompositor::CompositingState::propagateStateFromChildrenForUnchangedSubtree): Deleted.
(WebCore::RenderLayerCompositor::clipsCompositingDescendants const): Deleted.
* rendering/RenderLayerCompositor.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@245371 268f45cc-cd09-0410-ab3c-d52691b4dbfc