Properly avoid breaking inside a float's top margin.

third_party/WebKit/Source/core/layout/LayoutBlockFlow.h

Index: third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
index 89cff5807c64ac08f9a2b77384bf30d165cea7dd..f038ad305c54ee7b5c2b4c397ef57cd5a1ef321d 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
+++ b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
@@ -765,12 +765,6 @@ class CORE_EXPORT LayoutBlockFlow : public LayoutBlock {
     return maxPositiveMarginAfter() - maxNegativeMarginAfter();
   }
 
-  // Floats' margins do not collapse with page or column boundaries, and we
-  // therefore need to treat them specially in some cases.
-  LayoutUnit marginBeforeIfFloating() const {
-    return isFloating() ? marginBefore() : LayoutUnit();
-  }
-
   LayoutUnit collapseMargins(LayoutBox& child,
                              MarginInfo&,
                              bool childIsSelfCollapsing,