Make top-level patch injections be compilation unit under library.

tests/compiler/dart2js/patch_test.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.
 
 #import("../../../lib/compiler/implementation/leg.dart");
 #import("../../../lib/compiler/implementation/elements/elements.dart");
 #import("../../../lib/compiler/implementation/tree/tree.dart");
 #import("../../../lib/compiler/implementation/util/util.dart");
 #import("mock_compiler.dart");
 #import("parser_helper.dart");
 #import("dart:uri");
 
 Compiler applyPatch(String script, String patch) {
   String core = "$DEFAULT_CORELIB\n$script";
   MockCompiler compiler = new MockCompiler(coreSource: core);
-
   var uri = new Uri("core.dartp");
-  var patchScript = new Script(uri, new MockFile(patch));
-  var patchLibrary = new LibraryElement(patchScript);
-
-  compiler.patchParser.scanLibraryElements(patchLibrary);
-  compiler.applyLibraryPatch(compiler.coreLibrary, patchLibrary);
-
+  compiler.sourceFiles[uri.toString()] = new MockFile(patch);
+  compiler.patchParser.patchLibrary(uri, compiler.coreLibrary);
+  compiler.applyClassPatches(compiler.coreLibrary);
   return compiler;
 }
 
 Element ensure(compiler,
                String name,
                Element lookup(name),
                [bool isPatched = true,
                 bool hasBody = false,
                 bool isGetter = false]) {
   var element = lookup(buildSourceString(name));
@@ skipping 69 matching lines @@
          hasBody: true,
          isPatched: false);
 }
 
 main() {
   testPatchFunction();
   testPatchMember();
   testPatchGetter();
   testInjectFunction();
 }