Invalidate first line display item clients when first line style changes

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

Index: third_party/WebKit/Source/core/layout/LayoutBlockFlowLine.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlockFlowLine.cpp b/third_party/WebKit/Source/core/layout/LayoutBlockFlowLine.cpp
index 3d7b00a155cc56f05ddcf3cbe3f00a7405d4368f..546aec893b42a9d468c1a97e546b8350a89d1075 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlockFlowLine.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlockFlowLine.cpp
@@ -2065,4 +2065,12 @@ LayoutUnit LayoutBlockFlow::startAlignedOffsetForLine(LayoutUnit position, bool
     return logicalLeft;
 }
 
+void LayoutBlockFlow::invalidateDisplayItemClientsOfFirstLine()
+{
+    if (RootInlineBox* firstRootBox = this->firstRootBox())
+        firstRootBox->invalidateDisplayItemClientsOfFirstLine();
+    else if (firstChild()->isLayoutBlockFlow())

[chrishtr, 2015/12/01 01:43:11]

Add a comment explaining each side of the if ... else branch.

[mstensho (USE GERRIT), 2015/12/01 12:29:49]

How do we know that we have children at all? Also, this will enter any first
block flow child, including floats and out-of-flow positioned objects. That's
unnecessary, since they never apply ::fist-line rules from ancestors.

[Xianzhu, 2015/12/01 20:06:25]

Done.

[Xianzhu, 2015/12/01 20:06:25]

It seems that if the block has at least one non-inline child, it will be
!childrenInline(), otherwise it always has a root line box, so
   ASSERT(!firstRootBox() || firstChild())
However the above rule looks not explicit and I changed code to make it clearer.
Fixed.

+        toLayoutBlockFlow(firstChild())->invalidateDisplayItemClientsOfFirstLine();
+}
+
 }