1 files changed, 60 insertions, 11 deletions

diff --git a/chromium/third_party/blink/renderer/core/paint/compositing/compositing_inputs_updater.cc b/chromium/third_party/blink/renderer/core/paint/compositing/compositing_inputs_updater.cc
index d393de8bede..f7e9bdc5724 100644
--- a/chromium/third_party/blink/renderer/core/paint/compositing/compositing_inputs_updater.cc
+++ b/chromium/third_party/blink/renderer/core/paint/compositing/compositing_inputs_updater.cc
@@ -12,6 +12,7 @@
 #include "third_party/blink/renderer/core/paint/compositing/composited_layer_mapping.h"
 #include "third_party/blink/renderer/core/paint/compositing/paint_layer_compositor.h"
 #include "third_party/blink/renderer/core/paint/paint_layer.h"
+#include "third_party/blink/renderer/core/paint/paint_layer_scrollable_area.h"
 #include "third_party/blink/renderer/platform/instrumentation/tracing/trace_event.h"
 
 namespace blink {
@@ -23,8 +24,12 @@ static const LayoutBoxModelObject* ClippingContainerFromClipChainParent(
              : clip_chain_parent->ClippingContainer();
 }
 
-CompositingInputsUpdater::CompositingInputsUpdater(PaintLayer* root_layer)
-    : geometry_map_(kUseTransforms), root_layer_(root_layer) {}
+CompositingInputsUpdater::CompositingInputsUpdater(
+    PaintLayer* root_layer,
+    CompositingReasonFinder& compositing_reason_finder)
+    : geometry_map_(kUseTransforms),
+      root_layer_(root_layer),
+      compositing_reason_finder_(compositing_reason_finder) {}
 
 CompositingInputsUpdater::~CompositingInputsUpdater() = default;
 
@@ -36,10 +41,6 @@ void CompositingInputsUpdater::Update() {
 void CompositingInputsUpdater::UpdateRecursive(PaintLayer* layer,
                                                UpdateType update_type,
                                                AncestorInfo info) {
-  if (!layer->ChildNeedsCompositingInputsUpdate() &&
-      update_type != kForceUpdate)
-    return;
-
   LayoutBoxModelObject& layout_object = layer->GetLayoutObject();
   const ComputedStyle& style = layout_object.StyleRef();
 
@@ -165,7 +166,7 @@ void CompositingInputsUpdater::UpdateRecursive(PaintLayer* layer,
             ? info.clip_chain_parent_for_fixed
             : nullptr;
     // Workaround crbug.com/817175
-    // We can't escape clip to a layer that paints after us, because in SPv1*
+    // We can't escape clip to a layer that paints after us, because in SPv1
     // cc needs to reverse engineer clip tree from the layer tree, and we
     // can't refer to a clip node that hasn't been built yet.
     // This will result in wrong clip in some rare cases, for example:
@@ -189,11 +190,59 @@ void CompositingInputsUpdater::UpdateRecursive(PaintLayer* layer,
         info.needs_reparent_scroll_for_fixed = false;
   }
 
+  PaintLayerCompositor* compositor =
+      layer->GetLayoutObject().View()->Compositor();
+
+  // The sequence of updates to compositing triggers goes like this:
+  // 1. Apply all triggers from kComboAllDirectNonStyleDeterminedReasons for
+  //    |layer|. This may depend on ancestor composited scrolling (i.e. step
+  //    2 for an ancestor PaintLayer).
+  // 2. Put |layer| in composited scrolling mode if needed.
+  // 3. Reset DescendantHasDirectCompositingReason to false for |layer|.
+  // 4. Recurse into child PaintLayers.
+  // 5. Set DescendantHasDirectCompositingReason to true if it was for any
+  //    child.
+  // 6. If |layer| is the root, composite if
+  //    DescendantHasDirectCompositingReason is true for |layer|.
+  bool ignore_lcd_text =
+      (layer->AncestorScrollingLayer() &&
+       !layer->AncestorScrollingLayer()->IsRootLayer() &&
+       layer->AncestorScrollingLayer()->NeedsCompositedScrolling());
+
+  layer->SetPotentialCompositingReasonsFromNonStyle(
+      compositing_reason_finder_.NonStyleDeterminedDirectReasons(
+          layer, ignore_lcd_text));
+
+  if (layer->GetScrollableArea()) {
+    layer->GetScrollableArea()->UpdateNeedsCompositedScrolling(
+        compositor->CanBeComposited(layer) &&
+        layer->DirectCompositingReasons());
+  }
+
+  bool should_recurse =
+      layer->ChildNeedsCompositingInputsUpdate() || update_type == kForceUpdate;
+
+  layer->SetDescendantHasDirectOrScrollingCompositingReason(false);
+  bool descendant_has_direct_compositing_reason = false;
   for (PaintLayer* child = layer->FirstChild(); child;
-       child = child->NextSibling())
-    UpdateRecursive(child, update_type, info);
+       child = child->NextSibling()) {
+    if (should_recurse)
+      UpdateRecursive(child, update_type, info);
+    descendant_has_direct_compositing_reason |=
+        child->DescendantHasDirectOrScrollingCompositingReason() ||
+        child->NeedsCompositedScrolling() ||
+        (compositor->CanBeComposited(child) &&
+         child->DirectCompositingReasons());
+  }
+  layer->SetDescendantHasDirectOrScrollingCompositingReason(
+      descendant_has_direct_compositing_reason);
+
+  if (layer->IsRootLayer() && layer->ScrollsOverflow() &&
+      layer->DescendantHasDirectOrScrollingCompositingReason() &&
+      !layer->NeedsCompositedScrolling())
+    layer->GetScrollableArea()->UpdateNeedsCompositedScrolling(true);
 
-  layer->DidUpdateCompositingInputs();
+  layer->ClearChildNeedsCompositingInputsUpdate();
 
   geometry_map_.PopMappingsToAncestor(layer->Parent());
 
@@ -288,7 +337,7 @@ void CompositingInputsUpdater::UpdateAncestorDependentCompositingInputs(
   properties.clip_parent = info.escape_clip_to;
 
   properties.ancestor_scrolling_layer = info.scrolling_ancestor;
-  if (info.needs_reparent_scroll && layer->StackingNode()->IsStacked())
+  if (info.needs_reparent_scroll && layout_object.StyleRef().IsStacked())
     properties.scroll_parent = info.scrolling_ancestor;
 
   layer->UpdateAncestorDependentCompositingInputs(properties);