Re-apply "Clean up the patch file for the isolate library by introducing a new buitlin library: iso…

sdk/lib/_internal/compiler/implementation/compiler.dart

Index: sdk/lib/_internal/compiler/implementation/compiler.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/compiler.dart	(revision 16320)
+++ sdk/lib/_internal/compiler/implementation/compiler.dart	(working copy)
@@ -128,6 +128,7 @@
   Element _currentElement;
   LibraryElement coreLibrary;
   LibraryElement isolateLibrary;
+  LibraryElement isolateHelperLibrary;
   LibraryElement jsHelperLibrary;
   LibraryElement interceptorsLibrary;
   LibraryElement foreignLibrary;
@@ -402,12 +403,14 @@
   void enableIsolateSupport(LibraryElement element) {
     // TODO(ahe): Move this method to Enqueuer.
     isolateLibrary = element.patch;
-    enqueuer.resolution.addToWorkList(isolateLibrary.find(START_ROOT_ISOLATE));
     enqueuer.resolution.addToWorkList(
-        isolateLibrary.find(const SourceString('_currentIsolate')));
+        isolateHelperLibrary.find(START_ROOT_ISOLATE));
     enqueuer.resolution.addToWorkList(
-        isolateLibrary.find(const SourceString('_callInIsolate')));
-    enqueuer.codegen.addToWorkList(isolateLibrary.find(START_ROOT_ISOLATE));
+        isolateHelperLibrary.find(const SourceString('_currentIsolate')));
+    enqueuer.resolution.addToWorkList(
+        isolateHelperLibrary.find(const SourceString('_callInIsolate')));
+    enqueuer.codegen.addToWorkList(
+        isolateHelperLibrary.find(START_ROOT_ISOLATE));
   }
 
   bool hasIsolateSupport() => isolateLibrary != null;
@@ -463,6 +466,13 @@
     jsHelperLibrary = scanBuiltinLibrary('_js_helper');
     interceptorsLibrary = scanBuiltinLibrary('_interceptors');
     foreignLibrary = scanBuiltinLibrary('_foreign_helper');
+    isolateHelperLibrary = scanBuiltinLibrary('_isolate_helper');
+    // The helper library does not use the native language extension,
+    // so we manually set the native classes this library defines.
+    // TODO(ngeoffray): Enable annotations on these classes.
+    ClassElement cls =
+        isolateHelperLibrary.find(const SourceString('_WorkerStub'));
+    cls.setNative('"*Worker"');
 
     // The core library was loaded and patched before jsHelperLibrary was
     // initialized, so it wasn't imported into those two libraries during
@@ -473,6 +483,9 @@
     importForeignLibrary(jsHelperLibrary);
     importForeignLibrary(interceptorsLibrary);
 
+    importForeignLibrary(isolateHelperLibrary);
+    importHelperLibrary(isolateHelperLibrary);
+
     assertMethod = jsHelperLibrary.find(const SourceString('assertHelper'));
     identicalFunction = coreLibrary.find(const SourceString('identical'));
 
@@ -500,11 +513,17 @@
 
   /** Define the JS helper functions in the given library. */
   void importForeignLibrary(LibraryElement library) {
-    if (jsHelperLibrary != null) {
+    if (foreignLibrary != null) {
       libraryLoader.importLibrary(library, foreignLibrary, null);
     }
   }
 
+  void importIsolateHelperLibrary(LibraryElement library) {
+    if (isolateHelperLibrary != null) {
+      libraryLoader.importLibrary(library, isolateHelperLibrary, null);
+    }
+  }
+
   // TODO(karlklose,floitsch): move this to the javascript backend.
   /** Enable the 'JS' helper for a library if needed. */
   void maybeEnableJSHelper(LibraryElement library) {
@@ -513,7 +532,6 @@
         'dart/tests/compiler/dart2js_native');
     if (nativeTest
         || libraryName == 'dart:mirrors'
-        || libraryName == 'dart:isolate'
         || libraryName == 'dart:math'
         || libraryName == 'dart:html'
         || libraryName == 'dart:html_common'
@@ -540,12 +558,21 @@
     }
   }
 
+  void maybeEnableIsolateHelper(LibraryElement library) {
+    String libraryName = library.uri.toString();
+    if (libraryName == 'dart:isolate'
+        || libraryName == 'dart:html') {
+      importIsolateHelperLibrary(library);
+    }
+  }
+
   void runCompiler(Uri uri) {
     log('compiling $uri ($BUILD_ID)');
     scanBuiltinLibraries();
     mainApp = libraryLoader.loadLibrary(uri, null, uri);
     libraries.forEach((_, library) {
       maybeEnableJSHelper(library);
+      maybeEnableIsolateHelper(library);
     });
     final Element main = mainApp.find(MAIN);
     if (main == null) {