content-visibility: Resume graphics layer building if it was blocked.

This patch ensures that if we blocked a graphics layer rebuild because
of a display lock that we continue such a rebuild when the context
is unlocked (or rather we ensure that we rebuild the graphics layer
tree again).

R=wangxianzhu@chromium.org, chrishtr@chromium.org

Fixed: 1113838
Change-Id: I3b904f7c89c74c4d1a370b63382241c6729e1f3e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2342464
Commit-Queue: vmpstr <vmpstr@chromium.org>
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#795928}

third_party/blink/renderer/core/display_lock/display_lock_context.cc

@@ -737,6 +737,10 @@ bool DisplayLockContext::MarkForCompositingUpdatesIfNeeded() {
       layout_box->Layer()->SetNeedsCompositingInputsUpdate();
     needs_compositing_dependent_flag_update_ = false;
 
+    if (needs_graphics_layer_rebuild_)
+      layout_box->Layer()->SetNeedsGraphicsLayerRebuild();
+    needs_graphics_layer_rebuild_ = false;
+
     return true;
   }
   return false;

third_party/blink/renderer/core/display_lock/display_lock_context.h

@@ -162,6 +162,11 @@ class CORE_EXPORT DisplayLockContext final
     needs_compositing_dependent_flag_update_ = true;
   }
 
+  void NotifyGraphicsLayerRebuildBlocked() {
+    DCHECK(!RuntimeEnabledFeatures::CompositeAfterPaintEnabled());
+    needs_graphics_layer_rebuild_ = true;
+  }
+
   // Notify this element will be disconnected.
   void NotifyWillDisconnect();
 
@@ -363,6 +368,8 @@ class CORE_EXPORT DisplayLockContext final
   // again at the start of the lifecycle.
   bool keep_unlocked_until_lifecycle_ = false;
 
+  bool needs_graphics_layer_rebuild_ = false;
+
   enum class RenderAffectingState : int {
     kLockRequested,
     kIntersectsViewport,

third_party/blink/renderer/core/paint/compositing/graphics_layer_tree_builder.cc

@@ -88,6 +88,15 @@ void GraphicsLayerTreeBuilder::RebuildRecursive(
   bool recursion_blocked_by_display_lock =
       layer.GetLayoutObject().PrePaintBlockedByDisplayLock(
           DisplayLockLifecycleTarget::kChildren);
+  // If the recursion is blocked meaningfully (i.e. we would have recursed,
+  // since the layer has children), then we should inform the display-lock
+  // context that we blocked a graphics layer recursion, so that we can ensure
+  // to rebuild the tree once we're unlocked.
+  if (recursion_blocked_by_display_lock && layer.FirstChild()) {
+    auto* context = layer.GetLayoutObject().GetDisplayLockContext();
+    DCHECK(context);
+    context->NotifyGraphicsLayerRebuildBlocked();
+  }
 
   if (layer.IsStackingContextWithNegativeZOrderChildren()) {
     if (!recursion_blocked_by_display_lock) {

third_party/blink/renderer/core/paint/paint_layer.cc

@@ -1055,6 +1055,11 @@ void PaintLayer::SetNeedsCompositingInputsUpdate(bool mark_ancestor_flags) {
     MarkAncestorChainForFlagsUpdate(NeedsDescendantDependentUpdate);
 }
 
+void PaintLayer::SetNeedsGraphicsLayerRebuild() {
+  if (Compositor())
+    Compositor()->SetNeedsCompositingUpdate(kCompositingUpdateRebuildTree);
+}
+
 void PaintLayer::SetNeedsCheckRasterInvalidation() {
   DCHECK_EQ(GetLayoutObject().GetDocument().Lifecycle().GetState(),
             DocumentLifecycle::kInPrePaint);

third_party/blink/renderer/core/paint/paint_layer.h

@@ -821,6 +821,10 @@ class CORE_EXPORT PaintLayer : public DisplayItemClient {
   void SetNeedsVisualOverflowRecalc();
   void SetNeedsCompositingInputsUpdate(bool mark_ancestor_flags = true);
 
+  // Notifies the Compositor if one exists that it should rebuild the graphics
+  // layer tree.
+  void SetNeedsGraphicsLayerRebuild();
+
   // Mark this PaintLayer as needing raster invalidation checking after the
   // next compositing update step.
   void SetNeedsCheckRasterInvalidation();

third_party/blink/web_tests/FlagExpectations/composite-after-paint

@@ -41,7 +41,6 @@ crbug.com/802915 css3/blending/isolation-should-include-non-local-background.htm
 crbug.com/918155 virtual/prefer_compositing_to_lcd_text/scrollbars/overlay-scrollbar-over-child-layer-nested-2.html [ Pass ]
 crbug.com/918155 virtual/prefer_compositing_to_lcd_text/scrollbars/overlay-scrollbar-over-child-layer-nested.html [ Pass ]
 paint/invalidation/compositing/subpixel-offset-scaled-transform-composited.html [ Pass ]
-crbug.com/1113838 external/wpt/css/css-contain/content-visibility/content-visibility-074.html [ Pass ]
 
 # With CompositeAfterPaint and LayoutNGFragmentItem enabled
 crbug.com/1103138 paint/invalidation/compositing/float-under-composited-inline.html [ Pass Crash ]

third_party/blink/web_tests/TestExpectations

@@ -270,9 +270,6 @@ crbug.com/936084 external/wpt/css/css-sizing/max-content-input-001.html [ Failur
 # Incorrect blending with foreignObject and svg descendants.
 crbug.com/1102803 external/wpt/svg/extensibility/foreignObject/isolation-with-svg.html [ Failure ]
 
-# Display locking failures
-crbug.com/1113838 external/wpt/css/css-contain/content-visibility/content-visibility-074.html [ Failure ]
-
 crbug.com/849459 fragmentation/repeating-thead-under-repeating-thead.html [ Failure ]
 
 # These fail when device_scale_factor is changed, but only for anti-aliasing: