Revert "Bug 312451: Accessible.addRelations should check if target == null"

This reverts commit e6349257e05a89e01f81a9400e925d17523a77fc.

Change-Id: I01547e37854be77d50b2bb70aa452b0f4207858b

bundles/org.eclipse.swt/Eclipse SWT Accessibility/cocoa/org/eclipse/swt/accessibility/Accessible.java

diff --git a/bundles/org.eclipse.swt/Eclipse SWT Accessibility/cocoa/org/eclipse/swt/accessibility/Accessible.java b/bundles/org.eclipse.swt/Eclipse SWT Accessibility/cocoa/org/eclipse/swt/accessibility/Accessible.java
index 3327c59..1e06435 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT Accessibility/cocoa/org/eclipse/swt/accessibility/Accessible.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT Accessibility/cocoa/org/eclipse/swt/accessibility/Accessible.java
@@ -455,13 +455,11 @@
 	 *
 	 * @param type an <code>ACC</code> constant beginning with RELATION_* indicating the type of relation
 	 * @param target the accessible that is the target for this relation
-	 * @exception IllegalArgumentException ERROR_NULL_ARGUMENT - if the Accessible target is null
 	 *
 	 * @since 3.6
 	 */
 	public void addRelation(int type, Accessible target) {
 		checkWidget();
-		if (target == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
 		if (relations[type] == null) {
 			relations[type] = new Relation(this, type);
 		}
@@ -3082,13 +3080,11 @@
 	 *
 	 * @param type an <code>ACC</code> constant beginning with RELATION_* indicating the type of relation
 	 * @param target the accessible that is the target for this relation
-	 * @exception IllegalArgumentException ERROR_NULL_ARGUMENT - if the Accessible target is null
-	 * 
+	 *
 	 * @since 3.6
 	 */
 	public void removeRelation(int type, Accessible target) {
 		checkWidget();
-		if (target == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
 		if (relations[type] != null) {
 			relations[type].removeTarget(target);
 		}

bundles/org.eclipse.swt/Eclipse SWT Accessibility/gtk/org/eclipse/swt/accessibility/Accessible.java

diff --git a/bundles/org.eclipse.swt/Eclipse SWT Accessibility/gtk/org/eclipse/swt/accessibility/Accessible.java b/bundles/org.eclipse.swt/Eclipse SWT Accessibility/gtk/org/eclipse/swt/accessibility/Accessible.java
index af6b3c5..018fd36 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT Accessibility/gtk/org/eclipse/swt/accessibility/Accessible.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT Accessibility/gtk/org/eclipse/swt/accessibility/Accessible.java
@@ -412,12 +412,10 @@
 	 * @param type an <code>ACC</code> constant beginning with RELATION_* indicating the type of relation
 	 * @param target the accessible that is the target for this relation
 	 *
-	 * @exception IllegalArgumentException ERROR_NULL_ARGUMENT - if the Accessible target is null
 	 * @since 3.6
 	 */
 	public void addRelation(int type, Accessible target) {
 		checkWidget();
-		if (target == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
 		if (relations == null) relations = new ArrayList<>();
 		Relation relation = new Relation(type, target);
 		if (relations.indexOf(relation) != -1) return;
@@ -869,13 +867,12 @@
 	 *
 	 * @param type an <code>ACC</code> constant beginning with RELATION_* indicating the type of relation
 	 * @param target the accessible that is the target for this relation
-	 * @exception IllegalArgumentException ERROR_NULL_ARGUMENT - if the Accessible target is null
+	 *
 	 * @since 3.6
 	 */
 	public void removeRelation(int type, Accessible target) {
 		checkWidget();
 		if (relations == null) return;
-		if (target == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
 		Relation relation = new Relation(type, target);
 		int index = relations.indexOf(relation);
 		if (index == -1) return;

bundles/org.eclipse.swt/Eclipse SWT Accessibility/win32/org/eclipse/swt/accessibility/Accessible.java

diff --git a/bundles/org.eclipse.swt/Eclipse SWT Accessibility/win32/org/eclipse/swt/accessibility/Accessible.java b/bundles/org.eclipse.swt/Eclipse SWT Accessibility/win32/org/eclipse/swt/accessibility/Accessible.java
index 37147be..5ec04e2 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT Accessibility/win32/org/eclipse/swt/accessibility/Accessible.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT Accessibility/win32/org/eclipse/swt/accessibility/Accessible.java
@@ -1039,12 +1039,11 @@
 	 *
 	 * @param type an <code>ACC</code> constant beginning with RELATION_* indicating the type of relation
 	 * @param target the accessible that is the target for this relation
-	 * @exception IllegalArgumentException ERROR_NULL_ARGUMENT - if the Accessible target is null
+	 *
 	 * @since 3.6
 	 */
 	public void addRelation(int type, Accessible target) {
 		checkWidget();
-		if (target == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
 		if (relations[type] == null) {
 			relations[type] = new Relation(this, type);
 		}
@@ -1448,12 +1447,11 @@
 	 *
 	 * @param type an <code>ACC</code> constant beginning with RELATION_* indicating the type of relation
 	 * @param target the accessible that is the target for this relation
-	 * @exception IllegalArgumentException ERROR_NULL_ARGUMENT - if the Accessible target is null
+	 *
 	 * @since 3.6
 	 */
 	public void removeRelation(int type, Accessible target) {
 		checkWidget();
-		if (target == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
 		Relation relation = relations[type];
 		if (relation != null) {
 			relation.removeTarget(target);