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

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

Index: sdk/lib/_internal/compiler/js_lib/isolate_helper.dart
diff --git a/sdk/lib/_internal/compiler/js_lib/isolate_helper.dart b/sdk/lib/_internal/compiler/js_lib/isolate_helper.dart
index 2619c3507647e2935be43dd2490a19a7451ed0b0..ad6883c95f9c02494dc8b68050bf7d09cd08935f 100644
--- a/sdk/lib/_internal/compiler/js_lib/isolate_helper.dart
+++ b/sdk/lib/_internal/compiler/js_lib/isolate_helper.dart
@@ -753,29 +753,20 @@ class IsolateNatives {
   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) {