[Layout API] Add LayoutItem.isBR() and use from editing/VisibleUnits

third_party/WebKit/Source/core/layout/api/LayoutItem.h

Index: third_party/WebKit/Source/core/layout/api/LayoutItem.h
diff --git a/third_party/WebKit/Source/core/layout/api/LayoutItem.h b/third_party/WebKit/Source/core/layout/api/LayoutItem.h
index b0fe64efe4316165e8fd022813bd172cd1e97d10..101afa1d5bf61c0cb37d936be642ad9503700158 100644
--- a/third_party/WebKit/Source/core/layout/api/LayoutItem.h
+++ b/third_party/WebKit/Source/core/layout/api/LayoutItem.h
@@ -54,6 +54,11 @@ public:
         return m_layoutObject->isBox();
     }
 
+    bool isBR() const
+    {
+        return m_layoutObject->isBR();
+    }
+
     bool isLayoutBlock() const
     {
         return m_layoutObject->isLayoutBlock();