Bug 533647 - Make IPropertyChangeListener a @FunctionalInterface

Change-Id: Ifa3173d8aa7699156cb4707328e7c8c2c540db16
Signed-off-by: Mickael Istria <mistria@redhat.com>
diff --git a/bundles/org.eclipse.core.runtime/src/org/eclipse/core/runtime/Preferences.java b/bundles/org.eclipse.core.runtime/src/org/eclipse/core/runtime/Preferences.java
index 89b10f6..848bcda 100644
--- a/bundles/org.eclipse.core.runtime/src/org/eclipse/core/runtime/Preferences.java
+++ b/bundles/org.eclipse.core.runtime/src/org/eclipse/core/runtime/Preferences.java
@@ -269,6 +269,7 @@
 	 * three cases in their implementation of the property change listener.
 	 * </p>
 	 */
+	@FunctionalInterface
 	public interface IPropertyChangeListener extends EventListener {
 
 		/**