[webkit-changes] [WebKit/WebKit] 39ec74: [Books] Returning from Lock Screen shows a flash o...

[mattwoodrow]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 39ec746c46ceb11d77d4f0f65be943905484289c
      https://github.com/WebKit/WebKit/commit/39ec746c46ceb11d77d4f0f65be943905484289c
  Author: Matt Woodrow <mattwoodrow at apple.com>
  Date:   2024-01-11 (Thu, 11 Jan 2024)

  Changed paths:
    M Source/WebKit/GPUProcess/graphics/RemoteImageBufferSet.cpp
    M Source/WebKit/Shared/RemoteLayerTree/RemoteLayerBackingStore.h
    M Source/WebKit/Shared/RemoteLayerTree/RemoteLayerBackingStoreCollection.mm
    M Source/WebKit/Shared/RemoteLayerTree/RemoteLayerWithInProcessRenderingBackingStore.h
    M Source/WebKit/Shared/RemoteLayerTree/RemoteLayerWithRemoteRenderingBackingStore.h
    M Source/WebKit/Shared/RemoteLayerTree/RemoteLayerWithRemoteRenderingBackingStore.mm

  Log Message:
  -----------
  [Books] Returning from Lock Screen shows a flash of missing content
https://bugs.webkit.org/show_bug.cgi?id=267300
<rdar://119957147>

Reviewed by Simon Fraser.

If we've included an ImageBufferSet with an empty dirty region in the prepare for display
set, then we always need to return a valid buffer handle.

This happens when we think the front buffer is volatile (as happens when the screen is locked),
and we want to confirm that the contents are still there. If they are, no drawing is needed,
but we still need to update the buffer handle.

* Source/WebKit/GPUProcess/graphics/RemoteImageBufferSet.cpp:
(WebKit::RemoteImageBufferSet::ensureBufferForDisplay):
* Source/WebKit/Shared/RemoteLayerTree/RemoteLayerBackingStore.h:
* Source/WebKit/Shared/RemoteLayerTree/RemoteLayerBackingStoreCollection.mm:
(WebKit::RemoteLayerBackingStoreCollection::prepareBackingStoresForDisplay):
* Source/WebKit/Shared/RemoteLayerTree/RemoteLayerWithInProcessRenderingBackingStore.h:
* Source/WebKit/Shared/RemoteLayerTree/RemoteLayerWithRemoteRenderingBackingStore.h:
* Source/WebKit/Shared/RemoteLayerTree/RemoteLayerWithRemoteRenderingBackingStore.mm:
(WebKit::RemoteLayerWithRemoteRenderingBackingStore::prepareToDisplay):

Canonical link: https://commits.webkit.org/272932@main