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.core/src/org/eclipse/e4/ui/css/core/impl/engine/AbstractCSSEngine.java
Element elt = getElement(element);
		if (elt != null) {
			/*
			 * Compute new Style to apply.
			 */
			CSSStyleDeclaration style = viewCSS.getComputedStyle(elt, null);
			if (computeDefaultStyle) {
				if (applyStylesToChildNodes)
					this.computeDefaultStyle = computeDefaultStyle;
				/*
				 * Apply default style.
				 */
				applyDefaultStyleDeclaration(element, false, style, null);
			}
			/*
			 * Manage static pseudo instances
			 */
			String[] pseudoInstances = getStaticPseudoInstances(elt);
			if (pseudoInstances != null) {
				
				
				for (int i = 0; i < pseudoInstances.length; i++) {
					String pseudoInstance = pseudoInstances[i];
					CSSStyleDeclaration styleWithPseudoInstance = viewCSS
							.getComputedStyle(elt, pseudoInstance);
					if (computeDefaultStyle) {
						/*
						 * Apply default style for the current pseudo instance.
						 */
						applyDefaultStyleDeclaration(element, false,