6607660: java.awt.Container.getMouseEventTargetImpl should be invoked while holding the TreeLock

Summary: The body of the method has been wrapped into the synchronized (getTreeLock()) { } block.
Reviewed-by: son, art

src/share/classes/java/awt/Container.java

@@ -2267,6 +2267,7 @@ public class Container extends Component {
                                          EventTargetFilter filter,
                                          boolean searchHeavyweightChildren,
                                          boolean searchHeavyweightDescendants) {
+        synchronized (getTreeLock()) {
             int ncomponents = this.ncomponents;
             Component component[] = this.component;
 
@@ -2279,11 +2280,12 @@ public class Container extends Component {
                       !(comp.peer instanceof LightweightPeer))) &&
                     comp.contains(x - comp.x, y - comp.y)) {
 
-                // found a component that intersects the point, see if there is
-                // a deeper possibility.
+                    // found a component that intersects the point, see if there
+                    // is a deeper possibility.
                     if (comp instanceof Container) {
                         Container child = (Container) comp;
-                    Component deeper = child.getMouseEventTarget(x - child.x,
+                        Component deeper = child.getMouseEventTarget(
+                                x - child.x,
                                 y - child.y,
                                 includeSelf,
                                 filter,
@@ -2293,8 +2295,8 @@ public class Container extends Component {
                         }
                     } else {
                         if (filter.accept(comp)) {
-                        // there isn't a deeper target, but this component is a
-                        // target
+                            // there isn't a deeper target, but this component
+                            // is a target
                             return comp;
                         }
                     }
@@ -2307,14 +2309,15 @@ public class Container extends Component {
             isPeerOK = (peer instanceof LightweightPeer) || includeSelf;
             isMouseOverMe = contains(x,y);
 
-        // didn't find a child target, return this component if it's a possible
-        // target
+            // didn't find a child target, return this component if it's
+            // a possible target
             if (isMouseOverMe && isPeerOK && filter.accept(this)) {
                 return this;
             }
             // no possible target
             return null;
         }
+    }
 
     static interface EventTargetFilter {
         boolean accept(final Component comp);