Merge icons.ts with semantic_icons.ts

Change-Id: I618a155b0ee85888c22af438e14c588e85648b9a
diff --git a/ui/src/frontend/track_panel.ts b/ui/src/frontend/track_panel.ts
index d08ad8b..4d59dfa 100644
--- a/ui/src/frontend/track_panel.ts
+++ b/ui/src/frontend/track_panel.ts
@@ -15,7 +15,7 @@
 import {hex} from 'color-convert';
 import m from 'mithril';
 
-import {BLANK_CHECKBOX, CHECKBOX, PIN} from '../base/icons';
+import {Icons} from '../base/semantic_icons';
 import {duration, Span, time} from '../base/time';
 import {Actions} from '../common/actions';
 import {pluginManager} from '../common/plugins';
@@ -144,7 +144,7 @@
               globals.dispatch(
                   Actions.toggleTrackPinned({trackId: attrs.trackState.id}));
             },
-            i: PIN,
+            i: Icons.Pin,
             filledIcon: isPinned(attrs.trackState.id),
             tooltip: isPinned(attrs.trackState.id) ? 'Unpin' : 'Pin to top',
             showButton: isPinned(attrs.trackState.id),
@@ -158,7 +158,8 @@
                       {id: attrs.trackState.id, isTrackGroup: false}));
                   e.stopPropagation();
                 },
-                i: isSelected(attrs.trackState.id) ? CHECKBOX : BLANK_CHECKBOX,
+                i: isSelected(attrs.trackState.id) ? Icons.Checkbox :
+                                                     Icons.BlankCheckbox,
                 tooltip: isSelected(attrs.trackState.id) ?
                     'Remove track' :
                     'Add track to selection',