Re-apply 'Unify dart:isolate.' with fixes for autogenerated dart2js and dartium html files.

lib/compiler/implementation/compiler.dart

Index: lib/compiler/implementation/compiler.dart
diff --git a/lib/compiler/implementation/compiler.dart b/lib/compiler/implementation/compiler.dart
index 304dab8a47470cb23137f2603cb384a66a64e0a2..2a9ea4687a167511ca197463d1223ea53e700c68 100644
--- a/lib/compiler/implementation/compiler.dart
+++ b/lib/compiler/implementation/compiler.dart
@@ -379,9 +379,7 @@ class Compiler implements DiagnosticListener {
     if (library.isPatched) return;
     Uri patchUri = resolvePatchUri(dartLibraryPath);
     if (patchUri !== null) {
-       patchParser.patchLibrary(patchUri, library);
-      // We allow foreign functions in patched libraries.
-      addForeignFunctions(library);  // Is safe even if already added.
+      patchParser.patchLibrary(patchUri, library);
     }
   }