Bug 221521 [Markers] New markers API needs to be pared down
We have too much API in some of the new classes and they can be moved to internals
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/ProblemFilter.java
* (non-Javadoc)
			 * 
			 * @see org.eclipse.ui.IPluginContribution#getPluginId()
			 */
			public String getPluginId() {
				return namespace;
			}
		};
	}
	/**
	 * Return whether or not the receiver will be filtered out due to an
	 * activity match.
	 * 
	 * @return boolean <code>true</code> if it is filtered out.
	 */
	public boolean isFilteredOutByActivity() {
		if (contributionDescriptor == null) {
			return false;
		}
		if (identifier == null) {
			identifier = WorkbenchActivityHelper
					.getIdentifier(contributionDescriptor);
		}
		return !identifier.isEnabled();
	}
	public boolean isEnabled() {
		return super.isEnabled() && !isFilteredOutByActivity();
	}
}