fix compilation failure in mylyn-3.10.x build against Luna

Change-Id: Ic6e257f9e2c00bc0e79f422837f276bf11aa852b
Signed-off-by: Tomasz Zarna <tomasz.zarna@tasktop.com>
diff --git a/org.eclipse.mylyn.ide.ant/src/org/eclipse/mylyn/internal/ide/ant/AntStructureBridge.java b/org.eclipse.mylyn.ide.ant/src/org/eclipse/mylyn/internal/ide/ant/AntStructureBridge.java
index 1897946..28445bf 100644
--- a/org.eclipse.mylyn.ide.ant/src/org/eclipse/mylyn/internal/ide/ant/AntStructureBridge.java
+++ b/org.eclipse.mylyn.ide.ant/src/org/eclipse/mylyn/internal/ide/ant/AntStructureBridge.java
@@ -18,6 +18,7 @@
 import org.eclipse.ant.internal.ui.editor.text.AntAnnotationModel;
 import org.eclipse.ant.internal.ui.model.AntElementNode;
 import org.eclipse.ant.internal.ui.model.AntModel;
+import org.eclipse.ant.internal.ui.model.IAntElement;
 import org.eclipse.ant.internal.ui.model.IProblemRequestor;
 import org.eclipse.ant.internal.ui.model.LocationProvider;
 import org.eclipse.core.internal.resources.File;
@@ -84,7 +85,7 @@
 		if (o instanceof AntElementNode) {
 
 			// try to get the parent node
-			AntElementNode parent = ((AntElementNode) o).getParentNode();
+			IAntElement parent = ((AntElementNode) o).getParentNode();
 
 			if (parent != null) {
 				// get the handle for the parent node