717688 - ShadowLayersParent::RecvUpdate should update shadow properties for changed layers

Status: RESOLVED WONTFIX

(Core :: Graphics, defect)

Description

[Ali Juma [:ajuma]]

Currently, ShadowLayersParent::RecvUpdate does not update shadow properties (ShadowTransform, ShadowVisibleRegion, ShadowClipRect) for changed layers. Instead, these properties are updated by code that traverses the entire layer tree (TransformShadowTree in RenderFrameParent for e10s, and SetShadowProperties in CompositorParent for OMTC).

ShadowLayersParent::RecvUpdate should handle updating shadow properties, since it can update just the changed layers instead of the entire tree. Then, RenderFrameParent should recompute transforms only when needed.

Comment 1

[Joe Drew (not getting mail)]

Should this block bug 725095?

Comment 2

[Ali Juma [:ajuma]]

This is "nice to have", but not a blocker for landing or for beta IMHO.

Comment 3

[Chris Peterson [:cpeterson]]

Mass tracking-e10s flag change. Filter bugmail on "2be0fcce-e36a-4e2c-aa80-0e3d33eb5406".

Comment 4

[Brad Lassey [:blassey] (use needinfo?)]

Milan, do we care about this for e10s?

Comment 5

[Milan Sreckovic [:milan] (needinfo for best results)]

My understanding is that this is a potential performance optimization, though we don't know necessarily how much improvement we'd see.  The correctness should not depend on it getting fixed.  I would say that e10s should care about this only if we see a performance issue this would fix.