DevTools: make debugger's rawLocationToUILocation return nullable type

third_party/WebKit/Source/devtools/front_end/sources/CallStackSidebarPane.js

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 256 matching lines @@
    */
   _onContextMenu(event) {
     var item = this._list.itemForNode(/** @type {?Node} */ (event.target));
     if (!item)
       return;
     var contextMenu = new UI.ContextMenu(event);
     if (item.debuggerCallFrame)
       contextMenu.appendItem(Common.UIString('Restart frame'), () => item.debuggerCallFrame.restart());
     contextMenu.appendItem(Common.UIString('Copy stack trace'), this._copyStackTrace.bind(this));
     var location = this._itemLocation(item);
-    if (location) {
-      var uiLocation = Bindings.debuggerWorkspaceBinding.rawLocationToUILocation(location);
+    var uiLocation = location ? Bindings.debuggerWorkspaceBinding.rawLocationToUILocation(location) : null;
+    if (uiLocation)
       this.appendBlackboxURLContextMenuItems(contextMenu, uiLocation.uiSourceCode);
-    }
     contextMenu.show();
   }
 
   /**
    * @param {!Event} event
    */
   _onClick(event) {
     var item = this._list.itemForNode(/** @type {?Node} */ (event.target));
     if (item)
       this._activateItem(item);
@@ skipping 63 matching lines @@
     return this._list.selectPreviousItem(false /* canWrap */, false /* center */);
   }
 
   _copyStackTrace() {
     var text = [];
     for (var item of this._items) {
       if (item.promiseCreationFrame)
         continue;
       var itemText = this._itemTitle(item);
       var location = this._itemLocation(item);
-      if (location) {
-        var uiLocation = Bindings.debuggerWorkspaceBinding.rawLocationToUILocation(location);
+      var uiLocation = location ? Bindings.debuggerWorkspaceBinding.rawLocationToUILocation(location) : null;
+      if (uiLocation)
         itemText += ' (' + uiLocation.linkText(true /* skipTrim */) + ')';
-      }
       text.push(itemText);
     }
     InspectorFrontendHost.copyText(text.join('\n'));
   }
 
   /**
    * @param {function(!Array.<!UI.KeyboardShortcut.Descriptor>, function(!Event=):boolean)} registerShortcutDelegate
    */
   registerShortcuts(registerShortcutDelegate) {
     registerShortcutDelegate(
         UI.ShortcutsScreen.SourcesPanelShortcuts.NextCallFrame, this._selectNextCallFrameOnStack.bind(this));
     registerShortcutDelegate(
         UI.ShortcutsScreen.SourcesPanelShortcuts.PrevCallFrame, this._selectPreviousCallFrameOnStack.bind(this));
   }
 };
 
 /**
  * @typedef {{
  *     debuggerCallFrame: (SDK.DebuggerModel.CallFrame|undefined),
  *     asyncStackHeader: (string|undefined),
  *     runtimeCallFrame: (Protocol.Runtime.CallFrame|undefined),
  *     promiseCreationFrame: (Protocol.Runtime.CallFrame|undefined)
  * }}
  */
 Sources.CallStackSidebarPane.Item;