dart2js: compute the currentScript in the preamble for d8 and jsshell.

sdk/lib/_internal/compiler/js_lib/isolate_helper.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library _isolate_helper;
 
 import 'dart:_js_embedded_names' show
     CLASS_ID_EXTRACTOR,
     CLASS_FIELDS_EXTRACTOR,
     CREATE_NEW_ISOLATE,
@@ skipping 735 matching lines @@
   // TODO(herhut): Initialize this to false when able to track compile-time
   // constants.
   static var enableSpawnWorker;
 
   static String thisScript = computeThisScript();
 
   /// Associates an ID with a native worker object.
   static final Expando<int> workerIds = new Expando<int>();
 
   /**
-   * The src url for the script tag that loaded this Used to create
-   * JavaScript workers.
+   * The src url for the script tag that loaded this function.
+   *
+   * Used to create JavaScript workers and load deferred libraries.
    */
   static String computeThisScript() {
     var currentScript = JS_EMBEDDED_GLOBAL('', CURRENT_SCRIPT);

[floitsch, 2015/05/07 21:09:51]

The embedded global is set, if `document.currentScript` was found at init-time.

     if (currentScript != null) {
       return JS('String', 'String(#.src)', currentScript);
     }
-    if (Primitives.isD8) return computeThisScriptD8();

[herhut, 2015/05/08 08:06:27]

Do we still need the Primitives.isXX helpers? It would be great to get rid of
them if possible.

[floitsch, 2015/05/09 01:07:54]

Removed in https://codereview.chromium.org/1132923002/

-    if (Primitives.isJsshell) return computeThisScriptJsshell();
     // A worker has no script tag - so get an url from a stack-trace.
     if (_globalState.isWorker) return computeThisScriptFromTrace();
     return null;
   }
 
-  static String computeThisScriptJsshell() {
-    return JS('String|Null', 'thisFilename()');
-  }
-
-  // TODO(ahe): The following is for supporting D8.  We should move this code
-  // to a helper library that is only loaded when testing on D8.
-  static String computeThisScriptD8() => computeThisScriptFromTrace();
-
   static String computeThisScriptFromTrace() {
     var stack = JS('String|Null', 'new Error().stack');
     if (stack == null) {
       // According to Internet Explorer documentation, the stack
       // property is not set until the exception is thrown. The stack
       // property was not provided until IE10.
       stack = JS('String|Null',
                  '(function() {'
                  'try { throw new Error() } catch(e) { return e.stack }'
                  '})()');
@@ skipping 662 matching lines @@
   }
 
   bool operator==(Object other) {
     if (identical(other, this)) return true;
     if (other is CapabilityImpl) {
       return identical(_id, other._id);
     }
     return false;
   }
 }