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

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef LayoutItem_h
 #define LayoutItem_h
 
 #include "core/inspector/InspectorTraceEvents.h"
 #include "core/layout/LayoutObject.h"
 #include "wtf/Allocator.h"
@@ skipping 36 matching lines @@
     bool isBoxModelObject() const
     {
         return m_layoutObject->isBoxModelObject();
     }
 
     bool isBox() const
     {
         return m_layoutObject->isBox();
     }
 
+    bool isBR() const
+    {
+        return m_layoutObject->isBR();
+    }
+
     bool isLayoutBlock() const
     {
         return m_layoutObject->isLayoutBlock();
     }
 
     bool isText() const
     {
         return m_layoutObject->isText();
     }
 
@@ skipping 111 matching lines @@
     LayoutObject* layoutObject() { return m_layoutObject; }
     const LayoutObject* layoutObject() const { return m_layoutObject; }
 
 private:
     LayoutObject* m_layoutObject;
 };
 
 } // namespace blink
 
 #endif // LayoutItem_h