Hide "HideBotComments" if no bot comment is present in the history tab

Also-By: Dariusz Luksza <dluksza@collab.net>
Change-Id: Icf3ae5bfefa19941e85cf0c0699b33bc92ba647a
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ChangeScreen.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ChangeScreen.java
index b925444..0ab989f 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ChangeScreen.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ChangeScreen.java
@@ -302,6 +302,13 @@
                       .defaultBaseForMerges().getBase();
                 }
                 loadConfigInfo(info, base);
+                JsArray<MessageInfo> mAr = info.messages();
+                for (int i = 0; i < mAr.length(); i++) {
+                  if (mAr.get(i).tag() != null) {
+                    hideTaggedComments.setVisible(true);
+                    break;
+                  }
+                }
               }
             });
             group.done();
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ChangeScreen.ui.xml b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ChangeScreen.ui.xml
index 3a716c3..fe48eb9 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ChangeScreen.ui.xml
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ChangeScreen.ui.xml
@@ -608,6 +608,7 @@
         </g:Button>
         <g:Button ui:field='hideTaggedComments'
             styleName=''
+            visible='false'
             title='Hide tagged comments'>
           <ui:attribute name='title'/>
           <div><ui:msg>Hide tagged comments</ui:msg></div>