Invalidate first line display item clients when first line style changes

third_party/WebKit/Source/core/layout/LayoutObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1827 matching lines @@
         setStyle(style.release());
         return;
     }
 
     setStyle(pseudoStyle);
 }
 
 void LayoutObject::firstLineStyleDidChange(const ComputedStyle& oldStyle, const ComputedStyle& newStyle)
 {
     StyleDifference diff = oldStyle.visualInvalidationDiff(newStyle);
-    if (diff.hasDifference()) {
-        // TODO(rune@opera.com): We should use the diff to determine whether a repaint vs. layout
-        // is needed, but for now just assume a layout will be required. The diff code
-        // in LayoutObject::setStyle would need to be factored out so that it could be reused.
-        setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation(LayoutInvalidationReason::StyleChange);
+
+    if (diff.needsPaintInvalidation() || diff.textDecorationOrColorChanged()) {
+        LayoutBlock* block = nullptr;
+        if (isLayoutBlockFlow() || isLayoutButton()) {
+            block = toLayoutBlock(this);
+        } else if (isLayoutInline()) {
+            if (toLayoutInline(this)->firstLineBoxIncludingCulling()->isFirstLineStyle())

[mstensho (USE GERRIT), 2015/12/02 10:09:31]

Can't firstLineBoxIncludingCulling() return nullptr?

[Xianzhu, 2015/12/02 17:41:57]

Not sure though didn't encounter. Added nullptr checking.

+                block = containingBlock();
+        }
+        if (block) {
+            block->invalidateDisplayItemClientsOfFirstLine();
+            if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled())
+                block->setShouldDoFullPaintInvalidation();
+        }
     }
+    if (diff.needsLayout())
+        setNeedsLayoutAndPrefWidthsRecalc(LayoutInvalidationReason::StyleChange);
 }
 
 void LayoutObject::markContainingBlocksForOverflowRecalc()
 {
     for (LayoutBlock* container = containingBlock(); container && !container->childNeedsOverflowRecalcAfterStyleChange(); container = container->containingBlock())
         container->setChildNeedsOverflowRecalcAfterStyleChange();
 }
 
 void LayoutObject::setNeedsOverflowRecalcAfterStyleChange()
 {
@@ skipping 1643 matching lines @@
         const blink::LayoutObject* root = object1;
         while (root->parent())
             root = root->parent();
         root->showLayoutTreeAndMark(object1, "*", object2, "-", 0);
     } else {
         fprintf(stderr, "Cannot showLayoutTree. Root is (nil)\n");
     }
 }
 
 #endif