Bug 282890 [UI][CSS] Parts not always getting styled
I noticed a case where the perspective tab was getting styled but the other tabs weren't. There may be sequencing problems where we call too early to style the UI, then parts are added unstyled. This was in the legacy app. In order to ensure the styling engine is run, we should call the styling engine on SWTPartFactory.bindWidget().
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/workbench/ui/renderers/swt/SWTPartFactory.java
* HACK: Create a wrapper composite with appropriate layout for the purpose
	 * of styling margins. See bug #280632
	 */
	protected Composite createWrapperForStyling(Composite parentWidget) {
		Composite layoutHolder = new Composite(parentWidget, SWT.NONE);
		addLayoutForStyling(layoutHolder);
		layoutHolder.setData("org.eclipse.e4.ui.css.swt.marginWrapper", true); 
		return layoutHolder;
	}
	/*
	 * HACK: Add layout information to the composite for the purpose of styling
	 * margins. See bug #280632
	 */
	protected void addLayoutForStyling(Composite composite) {
		GridLayout gl = new GridLayout(1, true);
		composite.setLayout(gl);
		gl.horizontalSpacing = 0;
		gl.verticalSpacing = 0;
		gl.marginHeight = 0;
		gl.marginWidth = 0;
	}
	/*
	 * HACK: Prep the control with layout information for the purpose of styling
	 * margins. See bug #280632
	 */
	protected void configureForStyling(Control control) {
		control.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
	}
}