Remove frog dependencies from lib/compiler.

lib/compiler/implementation/native_handler.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('native');
-#import('../../uri/uri.dart');
+#import('dart:uri');
 #import('leg.dart');
 #import('elements/elements.dart');
 #import('scanner/scannerlib.dart');
 #import('ssa/ssa.dart');
 #import('tree/tree.dart');
 #import('util/util.dart');
 
 void processNativeClasses(Compiler compiler,
                           Collection<LibraryElement> libraries) {
   for (LibraryElement library in libraries) {
@@ skipping 342 matching lines @@
             const LiteralDartString('void'),
             <HInstruction>[jsClosure]));
       }
     });
     LiteralString jsCode = node.arguments.head;
     builder.push(new HForeign(jsCode.dartString,
                               const LiteralDartString('Object'),
                               <HInstruction>[]));
   }
 }