Make Analyzer, VM and dart2js accept URI strings as part-of library identifier.

pkg/compiler/lib/src/diagnostics/messages.dart

 // Copyright (c) 2011, 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.
 
 /**
  * The messages in this file should meet the following guide lines:
  *
  * 1. The message should be a complete sentence starting with an uppercase
  * letter, and ending with a period.
  *
@@ skipping 273 matching lines @@
   JS_INTEROP_CLASS_CANNOT_EXTEND_DART_CLASS,
   JS_INTEROP_CLASS_NON_EXTERNAL_MEMBER,
   JS_INTEROP_INDEX_NOT_SUPPORTED,
   JS_INTEROP_METHOD_WITH_NAMED_ARGUMENTS,
   JS_OBJECT_LITERAL_CONSTRUCTOR_WITH_POSITIONAL_ARGUMENTS,
   JS_PLACEHOLDER_CAPTURE,
   LIBRARY_NAME_MISMATCH,
   LIBRARY_NOT_FOUND,
   LIBRARY_NOT_SUPPORTED,
   LIBRARY_TAG_MUST_BE_FIRST,
+  LIBRARY_URI_MISMATCH,
   MAIN_HAS_PART_OF,
   MAIN_NOT_A_FUNCTION,
   MAIN_WITH_EXTRA_PARAMETER,
   MALFORMED_STRING_LITERAL,
   UNDEFINED_GETTER,
   MEMBER_NOT_STATIC,
   MEMBER_USES_CLASS_NAME,
   UNDEFINED_METHOD,
   MINUS_OPERATOR_BAD_ARITY,
   MIRROR_BLOAT,
@@ skipping 1765 matching lines @@
 part 'part.dart';
 
 main() {}
 """,
               'part.dart': """
 part of lib.bar;
 """
             }
           ]),
 
+      MessageKind.LIBRARY_URI_MISMATCH: const MessageTemplate(
+          MessageKind.LIBRARY_URI_MISMATCH,
+          "Expected URI of library '#{libraryUri}'.",
+          howToFix: "Try changing the directive to 'part of "
+                    "\"#{libraryUri}\";'.",
+          examples: const [
+            const {
+              'main.dart': """
+library lib.foo;
+
+part 'part.dart';
+
+main() {}
+""",
+              'part.dart': """
+part of "main.dart";
+"""
+            }
+          ]),
+
       MessageKind.MISSING_LIBRARY_NAME: const MessageTemplate(
           MessageKind.MISSING_LIBRARY_NAME,
           "Library has no name. Part directive expected library name "
           "to be '#{libraryName}'.",
           howToFix: "Try adding 'library #{libraryName};' to the library.",
           examples: const [
             const {
               'main.dart': """
 part 'part.dart';
 
@@ skipping 1716 matching lines @@
   static String convertToString(value) {
     if (value is ErrorToken) {
       // Shouldn't happen.
       return value.assertionMessage;
     } else if (value is Token) {
       value = value.value;
     }
     return '$value';
   }
 }