Cleanup isolate library after frog removal.

lib/isolate/dart2js/compiler_hooks.dart

Index: lib/isolate/dart2js/compiler_hooks.dart
diff --git a/lib/isolate/frog/compiler_hooks.dart b/lib/isolate/dart2js/compiler_hooks.dart
similarity index 80%
rename from lib/isolate/frog/compiler_hooks.dart
rename to lib/isolate/dart2js/compiler_hooks.dart
index 023e5fbb164817d1ab9a6272905b5374b0ed46a2..23759fa85631a4f97c4e2a4c9e9677855f0fcda8 100644
--- a/lib/isolate/frog/compiler_hooks.dart
+++ b/lib/isolate/dart2js/compiler_hooks.dart
@@ -2,14 +2,15 @@
 // 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.
 
-// This file contains functions that are used in the code generated by the frog
-// compiler.
+// This file contains functions that are used in the code generated by
+// the dart2js compiler.
 
 /**
  * Wrapper that takes the dart entry point and runs it within an isolate. The
- * frog compiler will inject a call of the form [: startRootIsolate(main); :]
- * when it determines that this wrapping is needed. For single-isolate
- * applications (e.g. hello world), this call is not emitted.
+ * dart2js compiler will inject a call of the form
+ * [: startRootIsolate(main); :] when it determines that this wrapping
+ * is needed. For single-isolate applications (e.g. hello world), this
+ * call is not emitted.
  */
 void startRootIsolate(entry) {
   _globalState = new _Manager();