Bug 205049 Other plug-ins should be able to define default content generator
Currently only the content generator can define which plug-ins it can be the default for - we need a way for plug-ins to refer back to the marker support for thier own generator.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/provisional/views/markers/api/MarkerField.java
return null;
		URL url = BundleUtility.find(configurationElement.getContributor()
				.getName(), path);
		if (url == null)
			return null;
		return IDEWorkbenchPlugin.getDefault().getResourceManager()
				.createImageWithDefault(ImageDescriptor.createFromURL(url));
	}
	/**
	 * @return The text to be displayed in the column header for this field.
	 */
	public String getColumnHeaderText() {
		return configurationElement.getAttribute(MarkerSupportConstants.ATTRIBUTE_NAME);
	}
	/**
	 * Get the number of characters that should be reserved for the receiver.
	 * 
	 * @param control the control to scale from
	 * @return int
	 */
	public int getDefaultColumnWidth(Control control) {
		return 15 * getFontWidth(control);
	}
	/**
	 * Determine the average width of font used by the control.
	 * @param control
	 * @return int
	 */
	public final int getFontWidth(Control control) {
		GC gc = new GC(control.getDisplay());