Only reload libraries when they may have been modified.

runtime/bin/vmservice_impl.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.
 
 #include "bin/vmservice_impl.h"
 
 #include "include/dart_api.h"
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
@@ skipping 299 matching lines @@
     FATAL1("vm-service: Could not find embedded source file: %s ", buffer);
   }
   ASSERT(r != Resources::kNoSuchInstance);
   return Dart_NewStringFromCString(vmservice_source);
 }
 
 
 Dart_Handle VmService::LoadScript(const char* name) {
   Dart_Handle uri = Dart_NewStringFromCString(kVMServiceIOLibraryUri);
   Dart_Handle source = GetSource(name);
-  return Dart_LoadScript(uri, source, 0, 0);
+  return Dart_LoadScript(uri, Dart_Null(), source, 0, 0);
 }
 
 
 Dart_Handle VmService::LoadLibrary(const char* name) {
   Dart_Handle uri = Dart_NewStringFromCString(kVMServiceIOLibraryUri);
   Dart_Handle source = GetSource(name);
-  return Dart_LoadLibrary(uri, source, 0, 0);
+  return Dart_LoadLibrary(uri, Dart_Null(), source, 0, 0);
 }
 
 
 Dart_Handle VmService::LoadSource(Dart_Handle library, const char* name) {
   Dart_Handle uri = Dart_NewStringFromCString(name);
   Dart_Handle source = GetSource(name);
-  return Dart_LoadSource(library, uri, source, 0, 0);
+  return Dart_LoadSource(library, uri, Dart_Null(), source, 0, 0);
 }
 
 
 Dart_Handle VmService::LibraryTagHandler(Dart_LibraryTag tag,
                                          Dart_Handle library,
                                          Dart_Handle url) {
   if (!Dart_IsLibrary(library)) {
     return Dart_NewApiError("not a library");
   }
   if (!Dart_IsString(url)) {
@@ skipping 16 matching lines @@
   }
   ASSERT((tag == Dart_kSourceTag) || (tag == Dart_kCanonicalizeUrl));
   if (tag == Dart_kCanonicalizeUrl) {
     // url is already canonicalized.
     return url;
   }
   Dart_Handle source = GetSource(url_string);
   if (Dart_IsError(source)) {
     return source;
   }
-  return Dart_LoadSource(library, url, source, 0, 0);
+  return Dart_LoadSource(library, url, Dart_Null(), source, 0, 0);
 }
 
 
 }  // namespace bin
 }  // namespace dart