DevTools: remove unused parts of the CSS instrumentation.

Source/core/inspector/InspectorInstrumentation.idl

 /*
 * Copyright (C) 2013 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
@@ skipping 87 matching lines @@
     [DOM, DOMDebugger, Inline=FastReturn]
     void didInvalidateStyleAttr([Keep] Node*);
 
     [DOM, Inline=FastReturn]
     void didPerformElementShadowDistribution([Keep] Element*);
 
     [CSS]
     void documentDetached([Keep] Document*);
 
     [CSS, Inline=FastReturn]
-    void willMutateRules(CSSStyleSheet*);
-
-    [CSS, Inline=FastReturn]
-    void didMutateRules([Keep] CSSStyleSheet*);
-
-    [CSS, Inline=FastReturn]
-    void willMutateStyle(CSSStyleDeclaration*);
-
-    [CSS, Inline=FastReturn]
-    void didMutateStyle([Keep] CSSStyleDeclaration*, bool);
-
-    [CSS, Inline=FastReturn]
     void activeStyleSheetsUpdated([Keep] Document*);
 
     [CSS, Inline=FastReturn]
     void mediaQueryResultChanged(Document*);
 
     [DOM, Inline=FastReturn]
     void didPushShadowRoot([Keep] Element* host, ShadowRoot*);
 
     [DOM, Inline=FastReturn]
     void willPopShadowRoot([Keep] Element* host, ShadowRoot*);
@@ skipping 318 matching lines @@
 interface InspectorOverrides {
     [CSS, Inline=FastReturn]
     bool forcePseudoState([Keep] Element* element, CSSSelector::PseudoType pseudoState);
 
     [Worker, Inline=FastReturn]
     bool shouldPauseDedicatedWorkerOnStart(ExecutionContext* context);
 
     [Resource, Inline=FastReturn]
     bool shouldForceCORSPreflight(Document*);
 }