Establish a list marker's offset before floats have been added to its line

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

Index: third_party/WebKit/Source/core/layout/LayoutListMarker.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutListMarker.cpp b/third_party/WebKit/Source/core/layout/LayoutListMarker.cpp
index 806cda731dc5b44a357ac400ce827d63b1162abc..5b56ad214f204ff6a8e212eb6cde084e31f8d3ae 100644
--- a/third_party/WebKit/Source/core/layout/LayoutListMarker.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutListMarker.cpp
@@ -43,7 +43,7 @@ const int cMarkerPaddingPx = 7;
 const int cUAMarkerMarginEm = 1;
 
 LayoutListMarker::LayoutListMarker(LayoutListItem* item)
-    : LayoutBox(nullptr), m_listItem(item) {
+    : LayoutBox(nullptr), m_listItem(item), m_lineOffset() {
   setInline(true);
   setIsAtomicInlineLevel(true);
 }
@@ -139,6 +139,17 @@ void LayoutListMarker::layout() {
   ASSERT(needsLayout());
   LayoutAnalyzer::Scope analyzer(*this);
 
+  LayoutUnit blockOffset;
+  for (LayoutBox* o = parentBox(); o != listItem(); o = o->parentBox()) {

[eae, 2016/12/07 21:30:45]

Is parentBox guaranteed to be non-null? If not we might want to change the
condition to:

o && o != listItem()

+    blockOffset += o->logicalTop();
+  }
+  if (listItem()->style()->isLeftToRightDirection()) {
+    m_lineOffset = listItem()->logicalLeftOffsetForLine(
+        blockOffset, DoNotIndentText, LayoutUnit());
+  } else {
+    m_lineOffset = listItem()->logicalRightOffsetForLine(
+        blockOffset, DoNotIndentText, LayoutUnit());
+  }
   if (isImage()) {
     updateMarginsAndContent();
     LayoutSize imageSize(imageBulletSize());