Bug 318944 CSSSWTEngineImpl leaks memory
CSSSWTEngineImpl stores too many element contexts. In a memory snapshot, the HashMap size was 15559. This is most probably a leak.
bundles/org.eclipse.e4.ui.css.swt/src/org/eclipse/e4/ui/css/swt/engine/CSSSWTEngineImpl.java
super.registerCSSProperty("shadow-visible", CSSPropertyShadowVisibleSWTHandler.class);  
		super.registerCSSPropertyHandler(CSSPropertyShadowVisibleSWTHandler.class,
				CSSPropertyShadowVisibleSWTHandler.INSTANCE);
		
		
		super.registerCSSProperty("outer-keyline-color", CSSPropertyOuterKeylineSWTHandler.class);  
		super.registerCSSPropertyHandler(CSSPropertyOuterKeylineSWTHandler.class,
				CSSPropertyOuterKeylineSWTHandler.INSTANCE);
		
		
		super.registerCSSProperty("inner-keyline-color", CSSPropertyInnerKeylineSWTHandler.class);  
		super.registerCSSPropertyHandler(CSSPropertyInnerKeylineSWTHandler.class,
				CSSPropertyInnerKeylineSWTHandler.INSTANCE);
		
		
		
		
		super.registerCSSProperty("webby-style", CSSPropertyWebbyStyleHandler.class);  
		super.registerCSSPropertyHandler(CSSPropertyWebbyStyleHandler.class,
				CSSPropertyWebbyStyleHandler.INSTANCE);
		
		super.registerCSSProperty("tab-margin-offset", CSSPropertyTabMarginOffsetHandler.class);  
		super.registerCSSPropertyHandler(CSSPropertyTabMarginOffsetHandler.class,
				CSSPropertyTabMarginOffsetHandler.INSTANCE);
	}
}