Add dart:web to VM.

runtime/bin/builtin_nolib.cc

 // 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.
 
 #include <stdio.h>
 
 #include "include/dart_api.h"
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
 
 
 Builtin::builtin_lib_props Builtin::builtin_libraries_[] = {
   /*      url_                 source_          has_natives_  */
   { DartUtils::kBuiltinLibURL, NULL,            true  },
   { DartUtils::kJsonLibURL,    NULL,            false },
   { DartUtils::kUriLibURL,     NULL,            false },
   { DartUtils::kCryptoLibURL,  NULL,            false },
   { DartUtils::kIOLibURL,      NULL,            true  },
-  { DartUtils::kUtfLibURL,     NULL,            false }
+  { DartUtils::kUtfLibURL,     NULL,            false },
+  { DartUtils::kWebLibURL,     web_source_,     false }
 };
 
 
 Dart_Handle Builtin::Source(BuiltinLibraryId id) {
-  UNREACHABLE();
-  return Dart_Null();
+  ASSERT((sizeof(builtin_libraries_) / sizeof(builtin_lib_props)) ==
+         kInvalidLibrary);
+  ASSERT(id == kWebLibrary);
+  return Dart_NewString(builtin_libraries_[id].source_);
 }
 
 
 void Builtin::SetupLibrary(Dart_Handle library, BuiltinLibraryId id) {
   ASSERT((sizeof(builtin_libraries_) / sizeof(builtin_lib_props)) ==
          kInvalidLibrary);
   ASSERT(id >= kBuiltinLibrary && id < kInvalidLibrary);
   if (builtin_libraries_[id].has_natives_) {
     // Setup the native resolver for built in library functions.
     DART_CHECK_VALID(Dart_SetNativeResolver(library, NativeLookup));
@@ skipping 17 matching lines @@
   DART_CHECK_VALID(library);
   return library;
 }
 
 
 void Builtin::ImportLibrary(Dart_Handle library, BuiltinLibraryId id) {
   Dart_Handle imported_library = LoadLibrary(id);
   // Import the library into current library.
   DART_CHECK_VALID(Dart_LibraryImportLibrary(library, imported_library));
 }