ChangeScreen2: Hide reply box when leaving the screen

If the reply box is open and the user clicks on a link to a
file with an inline comment, close the reply box. It should
not display over SideBySide2.

Change-Id: Idaed2f215181c75529f3cb1f3662cd7735a82dae

gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ChangeScreen2.java

@@ -212,6 +212,9 @@ public class ChangeScreen2 extends Screen {
 
   @Override
   protected void onUnload() {
+    if (replyAction != null) {
+      replyAction.hide();
+    }
     if (updateCheck != null) {
       updateCheck.cancel();
       updateCheck = null;

gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ReplyAction.java

@@ -62,6 +62,13 @@ class ReplyAction {
         : NativeMap.<JsArrayString> create();
   }
 
+  void hide() {
+    if (popup != null) {
+      popup.hide();
+    }
+    return;
+  }
+
   void onReply(MessageInfo msg) {
     if (popup != null) {
       popup.hide();