Add new slot for ported threads without a range

Change-Id: I5f4ecb35d4ecee6f56db7ae7a3029ce88775c5c7
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-processor/gr-diff-processor.ts b/polygerrit-ui/app/elements/diff/gr-diff-processor/gr-diff-processor.ts
index a0584b6..034081d 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-processor/gr-diff-processor.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-processor/gr-diff-processor.ts
@@ -22,6 +22,7 @@
   GrDiffLineType,
   FILE,
   Highlights,
+  LineNumber,
 } from '../gr-diff/gr-diff-line';
 import {
   GrDiffGroup,
@@ -150,7 +151,8 @@
     this.cancel();
 
     this.groups = [];
-    this.push('groups', this._makeFileComments());
+    this.push('groups', this._makeGroup('LOST'));
+    this.push('groups', this._makeGroup(FILE));
 
     // If it's a binary diff, we won't be rendering hunks of text differences
     // so finish processing.
@@ -450,10 +452,10 @@
     return line;
   }
 
-  _makeFileComments() {
+  _makeGroup(number: LineNumber) {
     const line = new GrDiffLine(GrDiffLineType.BOTH);
-    line.beforeNumber = FILE;
-    line.afterNumber = FILE;
+    line.beforeNumber = number;
+    line.afterNumber = number;
     return new GrDiffGroup(GrDiffGroupType.BOTH, [line]);
   }