Optimize outline paint invalidation

third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.cpp

Index: third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.cpp
diff --git a/third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.cpp b/third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.cpp
index b566d57efae8cf1c6442700c188c39af9662c424..e41d807fd6544a6a94e17a77747946445fe5ea3e 100644
--- a/third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.cpp
+++ b/third_party/WebKit/Source/core/paint/ObjectPaintInvalidator.cpp
@@ -488,14 +488,15 @@ ObjectPaintInvalidatorWithContext::computePaintInvalidationReason() {
   if (m_object.paintedOutputOfObjectHasNoEffectRegardlessOfSize())
     return PaintInvalidationNone;
 
-  const ComputedStyle& style = m_object.styleRef();
-
   // The outline may change shape because of position change of descendants. For
   // simplicity, just force full paint invalidation if this object is marked for

[chrishtr, 2017/02/03 02:00:11]

Comment needs updating.

[Xianzhu, 2017/02/03 04:38:35]

Done.

   // checking paint invalidation for any reason.
-  // TODO(wangxianzhu): Optimize this.
-  if (style.hasOutline())
+  if (m_object.outlineMayBeAffectedByDescendants() ||
+      m_object.previousOutlineMayBeAffectedByDescendants()) {
+    m_object.getMutableForPainting()
+        .updatePreviousOutlineMayBeAffectedByDescendants();
     return PaintInvalidationOutline;
+  }
 
   // If the size is zero on one of our bounds then we know we're going to have
   // to do a full invalidation of either old bounds or new bounds.