Correct box shadow overflow computation for InlineFlowBox

Source/core/layout/line/InlineFlowBox.cpp

Index: Source/core/layout/line/InlineFlowBox.cpp
diff --git a/Source/core/layout/line/InlineFlowBox.cpp b/Source/core/layout/line/InlineFlowBox.cpp
index 22885f2f095fe728d8b028bf7dc92e35bf8ca815..fd2ffe489607195849016283b8ec0f64993ea6b9 100644
--- a/Source/core/layout/line/InlineFlowBox.cpp
+++ b/Source/core/layout/line/InlineFlowBox.cpp
@@ -744,11 +744,13 @@ void InlineFlowBox::flipLinesInBlockDirection(LayoutUnit lineTop, LayoutUnit lin
 
 inline void InlineFlowBox::addBoxShadowVisualOverflow(LayoutRect& logicalVisualOverflow)
 {
-    // box-shadow on root line boxes is applying to the block and not to the lines.
-    if (!parent())
+    const ComputedStyle& style = layoutObject().styleRef(isFirstLineStyle());
+
+    // box-shadow on the block element applies to the block and not to the lines,
+    // unless it is modified by :first-line pseudo element.
+    if (!parent() && (!isFirstLineStyle() || &style == layoutObject().style()))

[fs, 2015/06/18 08:47:33]

This is also true for border-image outsets and outline (below), so seems
reasonable to extend those predicates in the same way.

         return;
 
-    const ComputedStyle& style = layoutObject().styleRef(isFirstLineStyle());
     WritingMode writingMode = style.writingMode();
     ShadowList* boxShadow = style.boxShadow();
     if (!boxShadow)