DevTools: make debugger's rawLocationToUILocation return nullable type

third_party/WebKit/Source/devtools/front_end/snippets/ScriptSnippetModel.js

 /*
  * Copyright (C) 2012 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 461 matching lines @@
   /**
    * @param {!Workspace.UISourceCode} uiSourceCode
    * @param {!Array.<!{breakpoint: !Bindings.BreakpointManager.Breakpoint, uiLocation: !Workspace.UILocation}>} breakpointLocations
    */
   _restoreBreakpoints(uiSourceCode, breakpointLocations) {
     var script = this._scriptForUISourceCode.get(uiSourceCode);
     if (!script)
       return;
     var rawLocation =
         /** @type {!SDK.DebuggerModel.Location} */ (this._debuggerModel.createRawLocation(script, 0, 0));
-    var scriptUISourceCode = Bindings.debuggerWorkspaceBinding.rawLocationToUILocation(rawLocation).uiSourceCode;
-    if (scriptUISourceCode)
-      this._scriptSnippetModel._restoreBreakpoints(scriptUISourceCode, breakpointLocations);
+    var uiLocation = Bindings.debuggerWorkspaceBinding.rawLocationToUILocation(rawLocation);
+    if (uiLocation)
+      this._scriptSnippetModel._restoreBreakpoints(uiLocation.uiSourceCode, breakpointLocations);
   }
 };
 
 /**
  * @implements {Common.ContentProvider}
  * @unrestricted
  */
 Snippets.SnippetContentProvider = class {
   /**
    * @param {!Snippets.Snippet} snippet
@@ skipping 114 matching lines @@
    */
   deleteFile(uiSourceCode) {
     this._model.deleteScriptSnippet(uiSourceCode);
   }
 };
 
 /**
  * @type {!Snippets.ScriptSnippetModel}
  */
 Snippets.scriptSnippetModel = new Snippets.ScriptSnippetModel(Workspace.workspace);