SideBySide2: Fix Reply and Done buttons

The newly created draft box is probably within the viewportMargin, as
it is created below the box the user clicked Reply or Done on.  Make
the DraftBox immediately visible instead of waiting for a redraw event
from CodeMirror.

Change-Id: I6f8dcab858729a6e7dfe6f1d4024a4a9784d36df

gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/SideBySide2.java

@@ -599,6 +599,7 @@ public class SideBySide2 extends Screen {
       return box;
     }
     addCommentBox(info, box);
+    box.setVisible(true);
     LineHandle handle = cm.getLineHandle(info.line() - 1);
     lineActiveBoxMap.put(handle, box);
     return box;
@@ -648,8 +649,8 @@ public class SideBySide2 extends Screen {
       box.setDiffChunkInfo(myChunk);
     }
     box.setGutterWrapper(diffTable.sidePanel.addGutter(cm, info.line() - 1,
-        box instanceof DraftBox ?
-            SidePanel.GutterType.DRAFT
+        box instanceof DraftBox
+          ? SidePanel.GutterType.DRAFT
           : SidePanel.GutterType.COMMENT));
     return box;
   }