Bug 305036 [Path Variables] Minor API changes in Dynamic Path Variables area
I'm attaching a patch illustrating what should be done in this area.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/dialogs/PathVariablesGroup.java
this.selectionListener = selectionListener;
    }
    /**
     * Opens a dialog for creating a new variable.
     */
    private void addNewVariable() {
        
        PathVariableDialog dialog = new PathVariableDialog(shell,
                PathVariableDialog.NEW_VARIABLE, variableType,
                pathVariableManager, tempPathVariables.keySet());
        dialog.setResource(currentResource);
        
        if (dialog.open() == Window.CANCEL) {
			return;
		}
        
        
        String newVariableName = dialog.getVariableName();
        IPath newVariableValue = new Path(dialog.getVariableValue());
        tempPathVariables.put(newVariableName, newVariableValue);
        
        updateWidgetState();
    }
    /**
     * Creates the widget group.
     * Callers must call <code>dispose</code> when the group is no 
     * longer needed.
     * 
     * @param parent the widget parent
     * @return container of the widgets