No need to re-collect stylesheets for setting type StyleChange.

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

 // Copyright 2014 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 StyleChangeReason_h
 #define StyleChangeReason_h
 
 #include "core/dom/QualifiedName.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/text/AtomicString.h"
@@ skipping 21 matching lines @@
 extern const char InlineCSSStyleMutated[];
 extern const char Inspector[];
 extern const char Language[];
 extern const char LinkColorChange[];
 extern const char PlatformColorChange[];
 extern const char PropagateInheritChangeToDistributedNodes[];
 extern const char PseudoClass[];
 extern const char SVGContainerSizeChange[];
 extern const char SVGCursor[];
 extern const char SVGFilterLayerUpdate[];
+extern const char Settings[];
 extern const char Shadow[];
 extern const char SiblingSelector[];
 extern const char StyleInvalidator[];
 extern const char StyleSheetChange[];
 extern const char Validate[];
 extern const char ViewportUnits[];
 extern const char VisitedLink[];
 extern const char VisuallyOrdered[];
 extern const char WritingModeChange[];
 extern const char Zoom[];
@@ skipping 48 matching lines @@
     void operator==(const StyleChangeReasonForTracing&) const { }
     void operator!=(const StyleChangeReasonForTracing&) const { }
 
     const char* m_reason;
     AtomicString m_extraData;
 };
 
 } // namespace blink
 
 #endif // StyleChangeReason_h