Fix canonicalization of --url_mapping URIs in gen_snapshot

runtime/bin/gen_snapshot.cc

 // Copyright (c) 2013, 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.
 
 // Generate a snapshot file after loading all the scripts specified on the
 // command line.
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ skipping 425 matching lines @@
     }
   }
 
   Dart_Handle result = failed ? Dart_NewApiError(result_string) :
                                 DartUtils::NewString(result_string);
   free(result_string);
   return result;
 }
 
 
+static Dart_Handle ResolveUri(const char* library_uri, const char* uri) {
+  bool failed = false;
+  char* result_string = NULL;
+
+  {
+    UriResolverIsolateScope scope;
+
+    // Run DartUtils::ResolveUri in context of uri resolver isolate.
+    Dart_Handle result = DartUtils::ResolveUri(
+      DartUtils::NewString(library_uri), DartUtils::NewString(uri));
+    if (Dart_IsError(result)) {
+      failed = true;
+      result_string = strdup(Dart_GetError(result));
+    } else {
+      result_string = strdup(DartUtils::GetStringValue(result));
+    }
+  }
+
+  Dart_Handle result = failed ? Dart_NewApiError(result_string) :
+                                DartUtils::NewString(result_string);
+  free(result_string);
+  return result;
+}
+
+
+
 static Builtin::BuiltinLibraryId BuiltinId(const char* url) {
   if (DartUtils::IsDartBuiltinLibURL(url)) {
     return Builtin::kBuiltinLibrary;
   }
   if (DartUtils::IsDartIOLibURL(url)) {
     return Builtin::kIOLibrary;
   }
   return Builtin::kInvalidLibrary;
 }
 
@@ skipping 25 matching lines @@
 
   Builtin::BuiltinLibraryId libraryBuiltinId = BuiltinId(library_url_string);
   if (tag == Dart_kCanonicalizeUrl) {
     if (mapped_url_string) {
       return url;
     }
     // Parts of internal libraries are handled internally.
     if (libraryBuiltinId != Builtin::kInvalidLibrary) {
       return url;
     }
-    return Dart_DefaultCanonicalizeUrl(library, url);
+    return ResolveUri(library_url_string, url_string);
   }
 
   Builtin::BuiltinLibraryId builtinId = BuiltinId(url_string);
   if ((builtinId != Builtin::kInvalidLibrary) && (mapped_url_string == NULL)) {
     // Special case for importing a builtin library that isn't remapped.
     if (tag == Dart_kImportTag) {
       return Builtin::LoadLibrary(url, builtinId);
     }
     ASSERT(tag == Dart_kSourceTag);
     return DartUtils::NewError("Unable to part '%s' ", url_string);
@@ skipping 821 matching lines @@
   EventHandler::Stop();
   return 0;
 }
 
 }  // namespace bin
 }  // namespace dart
 
 int main(int argc, char** argv) {
   return dart::bin::main(argc, argv);
 }