Remove unused StyleChangeReasons.

third_party/WebKit/Source/core/dom/StyleChangeReason.cpp

Index: third_party/WebKit/Source/core/dom/StyleChangeReason.cpp
diff --git a/third_party/WebKit/Source/core/dom/StyleChangeReason.cpp b/third_party/WebKit/Source/core/dom/StyleChangeReason.cpp
index eeeddf41467be153a477fa8014d1e65bb6aeba7c..4c496622f27e259280489cfba0581485a30be884 100644
--- a/third_party/WebKit/Source/core/dom/StyleChangeReason.cpp
+++ b/third_party/WebKit/Source/core/dom/StyleChangeReason.cpp
@@ -19,7 +19,6 @@ const char ControlValue[] = "ControlValue";
 const char Control[] = "Control";
 const char DeclarativeContent[] = "Extension declarativeContent.css";
 const char DesignMode[] = "DesignMode";
-const char Drag[] = "Drag";
 const char FontSizeChange[] = "FontSizeChange";
 const char Fonts[] = "Fonts";
 const char FullScreen[] = "FullScreen";
@@ -36,10 +35,8 @@ const char SVGCursor[] = "SVGCursor";
 const char SVGFilterLayerUpdate[] = "SVGFilterLayerUpdate";
 const char Settings[] = "Settings";
 const char Shadow[] = "Shadow";
-const char SiblingSelector[] = "SiblingSelector";
 const char StyleInvalidator[] = "StyleInvalidator";
 const char StyleSheetChange[] = "StyleSheetChange";
-const char Validate[] = "Validate";
 const char ViewportUnits[] = "ViewportUnits";
 const char VisitedLink[] = "VisitedLink";
 const char VisuallyOrdered[] = "VisuallyOrdered";