commit fe02d573f7e3b309f7da45fc84a9f2e232740b26
author Manuel Rego Casasnovas <rego@igalia.com> Thu Feb 06 07:58:13 2020
committer Commit Bot <commit-bot@chromium.org> Thu Feb 06 07:58:13 2020
tree ff2fed08469636dd6ecbf964a669df240c30d26c
parent 8f2f42431b0846bf434c9f2aba193a8269452ad8

Stop marking containers if overflow recalc flag is present

Basically we can avoid marking all the ancestors
in LayoutObject::MarkContainerChainForOverflowRecalcIfNeeded()
if the overflow recalc flags are already set.

BUG=941180

Change-Id: Ic8480a8d7a9fd7a2b7f35ff9ffb4ae10742098e6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2028228
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Commit-Queue: Manuel Rego <rego@igalia.com>
Cr-Commit-Position: refs/heads/master@{#738875}

third_party/blink/renderer/core/layout/layout_object.cc

diff --git a/third_party/blink/renderer/core/layout/layout_object.cc b/third_party/blink/renderer/core/layout/layout_object.cc
index 0b2658e..a04b22cd 100644
--- a/third_party/blink/renderer/core/layout/layout_object.cc
+++ b/third_party/blink/renderer/core/layout/layout_object.cc
@@ -2011,9 +2011,18 @@
                  ? object->Parent()
                  : object->Container();
     if (object) {
-      if (mark_container_chain_layout_overflow_recalc)
+      bool no_changes = true;
+      if (mark_container_chain_layout_overflow_recalc &&
+          !object->SelfNeedsLayoutOverflowRecalc()) {
         object->SetChildNeedsLayoutOverflowRecalc();
-      object->MarkSelfPaintingLayerForVisualOverflowRecalc();
+        no_changes = false;
+      }
+      if (!object->SelfPaintingLayerNeedsVisualOverflowRecalc()) {
+        object->MarkSelfPaintingLayerForVisualOverflowRecalc();
+        no_changes = false;
+      }
+      if (no_changes)
+        return;
     }
 
   } while (object);