Devtools [LayoutEditor]: Support an editing of ems/rems/percentage

Source/core/inspector/LayoutEditor.h

 // Copyright 2015 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 LayoutEditor_h
 #define LayoutEditor_h
 
 #include "core/CSSPropertyNames.h"
 #include "core/CoreExport.h"
+#include "core/css/CSSPrimitiveValue.h"
 #include "core/dom/Node.h"
 #include "core/inspector/InspectorOverlayHost.h"
 #include "platform/heap/Handle.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/RefPtr.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class CSSPrimitiveValue;
@@ skipping 22 matching lines @@
 
     // InspectorOverlayHost::LayoutEditorListener implementation.
     void overlayStartedPropertyChange(const String&) override;
     void overlayPropertyChanged(float) override;
     void overlayEndedPropertyChange() override;
 
     RefPtrWillBeMember<Element> m_element;
     RawPtrWillBeMember<InspectorCSSAgent> m_cssAgent;
     CSSPropertyID m_changingProperty;
     float m_propertyInitialValue;
+    float m_factor;
+    CSSPrimitiveValue::UnitType m_valueUnitType;
 };
 
 } // namespace blink
 
 
 #endif // !defined(LayoutEditor_h)