diff --git a/runtime/bin/loader.cc b/runtime/bin/loader.cc
index 8e24f67..19150a7 100644
--- a/runtime/bin/loader.cc
+++ b/runtime/bin/loader.cc
@@ -16,6 +16,8 @@
 
 // Development flag.
 static bool trace_loader = false;
+// Keep in sync with loader.dart.
+static const intptr_t _Dart_kImportExtension = 9;
 
 Loader::Loader(IsolateData* isolate_data)
     : port_(ILLEGAL_PORT),
@@ -152,6 +154,29 @@
 }
 
 
+void Loader::SendImportExtensionRequest(Dart_Handle url,
+                                        Dart_Handle library_url) {
+  // This port delivers loading messages to the service isolate.
+  Dart_Port loader_port = Builtin::LoadPort();
+  ASSERT(loader_port != ILLEGAL_PORT);
+
+
+  Dart_Handle request = Dart_NewList(6);
+  Dart_ListSetAt(request, 0, trace_loader ? Dart_True() : Dart_False());
+  Dart_ListSetAt(request, 1, Dart_NewInteger(Dart_GetMainPortId()));
+  Dart_ListSetAt(request, 2, Dart_NewInteger(_Dart_kImportExtension));
+  Dart_ListSetAt(request, 3, Dart_NewSendPort(port_));
+
+  Dart_ListSetAt(request, 4, url);
+  Dart_ListSetAt(request, 5, library_url);
+
+  if (Dart_Post(loader_port, request)) {
+    MonitorLocker ml(monitor_);
+    pending_operations_++;
+  }
+}
+
+
 // Forward a request from the tag handler to the service isolate.
 void Loader::SendRequest(Dart_LibraryTag tag,
                          Dart_Handle url,
@@ -229,6 +254,15 @@
 }
 
 
+static bool IsWindowsHost() {
+#if defined(TARGET_OS_WINDOWS)
+  return true;
+#else  // defined(TARGET_OS_WINDOWS)
+  return false;
+#endif  // defined(TARGET_OS_WINDOWS)
+}
+
+
 bool Loader::ProcessResultLocked(Loader* loader, Loader::IOResult* result) {
   // We have to copy everything we care about out of |result| because after
   // dropping the lock below |result| may no longer valid.
@@ -258,6 +292,30 @@
   }
 
 
+  if (result->tag == _Dart_kImportExtension) {
+    ASSERT(library_uri != Dart_Null());
+    Dart_Handle library = Dart_LookupLibrary(library_uri);
+    ASSERT(!Dart_IsError(library));
+    const char* lib_path_str = reinterpret_cast<const char*>(result->payload);
+    const char* extension_uri = reinterpret_cast<const char*>(result->uri);
+    const char* extension_path = DartUtils::RemoveScheme(extension_uri);
+    if (strchr(extension_path, '/') != NULL ||
+        (IsWindowsHost() && strchr(extension_path, '\\') != NULL)) {
+      loader->error_ = DartUtils::NewError(
+          "Relative paths for dart extensions are not supported: '%s'",
+          extension_path);
+      return false;
+    }
+    Dart_Handle result = Extensions::LoadExtension(lib_path_str,
+                                                   extension_path,
+                                                   library);
+    if (Dart_IsError(result)) {
+      loader->error_ = result;
+      return false;
+    }
+    return true;
+  }
+
   // Check for payload and load accordingly.
   bool is_snapshot = false;
   const uint8_t* payload = result->payload;
@@ -355,15 +413,6 @@
 }
 
 
-static bool IsWindowsHost() {
-#if defined(TARGET_OS_WINDOWS)
-  return true;
-#else  // defined(TARGET_OS_WINDOWS)
-  return false;
-#endif  // defined(TARGET_OS_WINDOWS)
-}
-
-
 void Loader::InitForSnapshot(const char* snapshot_uri) {
   IsolateData* isolate_data =
       reinterpret_cast<IsolateData*>(Dart_CurrentIsolateData());
@@ -465,7 +514,7 @@
   }
 
   if (DartUtils::IsDartExtensionSchemeURL(url_string)) {
-    // Load a native code shared library to use in a native extension
+    // Handle early error cases for dart-ext: imports.
     if (tag != Dart_kImportTag) {
       return DartUtils::NewError("Dart extensions must use import: '%s'",
                                  url_string);
@@ -474,19 +523,6 @@
     if (Dart_IsError(library_url)) {
       return library_url;
     }
-    Dart_Handle library_file_path = DartUtils::LibraryFilePath(library_url);
-    const char* lib_path_str = NULL;
-    Dart_StringToCString(library_file_path, &lib_path_str);
-    const char* extension_path = DartUtils::RemoveScheme(url_string);
-    if (strchr(extension_path, '/') != NULL ||
-        (IsWindowsHost() && strchr(extension_path, '\\') != NULL)) {
-      return DartUtils::NewError(
-          "Relative paths for dart extensions are not supported: '%s'",
-          extension_path);
-    }
-    return Extensions::LoadExtension(lib_path_str,
-                                     extension_path,
-                                     library);
   }
 
   IsolateData* isolate_data =
@@ -523,10 +559,15 @@
   ASSERT(loader != NULL);
   ASSERT(isolate_data->HasLoader());
 
-  loader->SendRequest(tag,
-                      url,
-                      (library != Dart_Null()) ?
-                          Dart_LibraryUrl(library) : Dart_Null());
+  if (DartUtils::IsDartExtensionSchemeURL(url_string)) {
+    loader->SendImportExtensionRequest(url, Dart_LibraryUrl(library));
+  } else {
+    loader->SendRequest(tag,
+                        url,
+                        (library != Dart_Null()) ?
+                            Dart_LibraryUrl(library) : Dart_Null());
+  }
+
 
   if (blocking_call) {
     // The outer invocation of the tag handler will block here until all nested
diff --git a/runtime/bin/loader.h b/runtime/bin/loader.h
index 088ce2e..034138e 100644
--- a/runtime/bin/loader.h
+++ b/runtime/bin/loader.h
@@ -82,6 +82,10 @@
             const char* working_directory,
             const char* root_script_uri);
 
+  // Send a request for a dart-ext: import to the service isolate.
+  void SendImportExtensionRequest(Dart_Handle url,
+                                  Dart_Handle library_url);
+
   // Send a request from the tag handler to the service isolate.
   void SendRequest(Dart_LibraryTag tag,
                    Dart_Handle url,
diff --git a/runtime/bin/vmservice/loader.dart b/runtime/bin/vmservice/loader.dart
index cb6792b..7686f1c 100644
--- a/runtime/bin/vmservice/loader.dart
+++ b/runtime/bin/vmservice/loader.dart
@@ -339,6 +339,25 @@
   sp.send(msg);
 }
 
+// Send a response to the requesting isolate.
+void _sendExtensionImportResponse(SendPort sp,
+                                  Uri uri,
+                                  String libraryUrl,
+                                  String resolvedUri) {
+  var msg = new List(4);
+  int tag = _Dart_kImportExtension;
+  if (resolvedUri == null) {
+    // We could not resolve the dart-ext: uri.
+    tag = -tag;
+    resolvedUri = 'Could not resolve "$uri" from "$libraryUrl"';
+  }
+  msg[0] = tag;
+  msg[1] = uri.toString();
+  msg[2] = libraryUrl;
+  msg[3] = resolvedUri;
+  sp.send(msg);
+}
+
 void _loadHttp(SendPort sp,
                int tag,
                Uri uri,
@@ -880,6 +899,7 @@
 const _Dart_kGetPackageRootUri = 6;    // Uri of the packages/ directory.
 const _Dart_kGetPackageConfigUri = 7;  // Uri of the .packages file.
 const _Dart_kResolvePackageUri = 8;    // Resolve a package: uri.
+const _Dart_kImportExtension = 9;      // Import a dart-ext: file.
 
 // External entry point for loader requests.
 _processLoadRequest(request) {
@@ -990,6 +1010,57 @@
         sp.send(resolvedUri);
       });
     break;
+    case _Dart_kImportExtension:
+      Uri uri = Uri.parse(request[4]);
+      String libraryUri = request[5];
+      // Strip any filename off of the libraryUri's path.
+      int index = libraryUri.lastIndexOf('/');
+      var path;
+      if (index == -1) {
+        path = './';
+      } else {
+        path = libraryUri.substring(0, index + 1);
+      }
+      var pathUri = Uri.parse(path);
+      switch (pathUri.scheme) {
+        case '':
+        case 'file':
+          _sendExtensionImportResponse(sp, uri, libraryUri,
+                                       pathUri.toFilePath());
+        break;
+        case 'data':
+        case 'http':
+        case 'https':
+          _sendExtensionImportResponse(sp, uri, libraryUri,
+                                       pathUri.toString());
+        break;
+        case 'package':
+          // Start package resolution.
+          loaderState._triggerPackageResolution(() {
+            // Attempt to find the fully resolved uri of [path].
+            Uri resolvedUri;
+            try {
+              resolvedUri = loaderState._resolvePackageUri(pathUri);
+            } catch (e, s) {
+              if (traceLoading) {
+                _log("Exception ($e) when resolving package URI: $uri");
+              }
+              resolvedUri = null;
+            }
+            _sendExtensionImportResponse(sp,
+                                         uri,
+                                         libraryUri,
+                                         resolvedUri.toString());
+          });
+        break;
+        default:
+          if (traceLoading) {
+            _log('Unknown scheme (${pathUri.scheme}) in $pathUri.');
+          }
+          _sendExtensionImportResponse(sp, uri, libraryUri, null);
+        break;
+      }
+    break;
     default:
       _log('Unknown loader request tag=$tag from $isolateId');
   }
diff --git a/sdk/lib/web_audio/dart2js/web_audio_dart2js.dart b/sdk/lib/web_audio/dart2js/web_audio_dart2js.dart
index 2a7e664..b178851 100644
--- a/sdk/lib/web_audio/dart2js/web_audio_dart2js.dart
+++ b/sdk/lib/web_audio/dart2js/web_audio_dart2js.dart
@@ -483,12 +483,14 @@
   void disconnect([destination_OR_output, int output, int input]) native;
 
   @DomName('AudioNode.connect')
-  void connectNode(AudioNode destination, [int output = 0, int input = 0]) =>
-      _connect(destination, output, input);
+  void connectNode(AudioNode destination, [int output = 0, int input = 0]) {
+    _connect(destination, output, input);
+  }
 
   @DomName('AudioNode.connect')
-  void connectParam(AudioParam destination, [int output = 0]) =>
-      _connect(destination, output);
+  void connectParam(AudioParam destination, [int output = 0]) {
+    _connect(destination, output);
+  }
 }
 // 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
diff --git a/sdk/lib/web_audio/dartium/web_audio_dartium.dart b/sdk/lib/web_audio/dartium/web_audio_dartium.dart
index c73b31b..6fd5356 100644
--- a/sdk/lib/web_audio/dartium/web_audio_dartium.dart
+++ b/sdk/lib/web_audio/dartium/web_audio_dartium.dart
@@ -689,12 +689,14 @@
   }
 
   @DomName('AudioNode.connect')
-  void connectNode(AudioNode destination, [int output = 0, int input = 0]) =>
-      _connect(destination, output, input);
+  void connectNode(AudioNode destination, [int output = 0, int input = 0]) {
+    _connect(destination, output, input);
+  }
 
   @DomName('AudioNode.connect')
-  void connectParam(AudioParam destination, [int output = 0]) =>
-      _connect(destination, output);
+  void connectParam(AudioParam destination, [int output = 0]) {
+    _connect(destination, output);
+  }
 }
 // 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
diff --git a/tools/VERSION b/tools/VERSION
index 6fb4f1b..9a83b13 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -28,4 +28,4 @@
 MINOR 18
 PATCH 0
 PRERELEASE 4
-PRERELEASE_PATCH 0
+PRERELEASE_PATCH 1
diff --git a/tools/deps/dartium.deps/DEPS b/tools/deps/dartium.deps/DEPS
index c526711..a12cdc3 100644
--- a/tools/deps/dartium.deps/DEPS
+++ b/tools/deps/dartium.deps/DEPS
@@ -8,8 +8,8 @@
 # Now we need to override some settings and add some new ones.
 
 vars.update({
-  "dartium_chromium_commit": "ef7d4ae18c646aea34c07a7ef62de7342c3b8c12",
-  "dartium_webkit_commit": "e77699b350f3e76be2d6f4e06af37615d3d6e778",
+  "dartium_chromium_commit": "67a7ba9669f7bb0300ef35085d4e6bb98b1966cc",
+  "dartium_webkit_commit": "d3db7d1b53979ca91cbf8f3117971f49d0fddf13",
   "chromium_base_revision": "338390",
 
   # We use mirrors of all github repos to guarantee reproducibility and
diff --git a/tools/dom/templates/html/impl/impl_AudioNode.darttemplate b/tools/dom/templates/html/impl/impl_AudioNode.darttemplate
index 43db4b3..e5ba37a 100644
--- a/tools/dom/templates/html/impl/impl_AudioNode.darttemplate
+++ b/tools/dom/templates/html/impl/impl_AudioNode.darttemplate
@@ -7,10 +7,12 @@
 $(ANNOTATIONS)$(NATIVESPEC)class $CLASSNAME$EXTENDS$IMPLEMENTS {
 $!MEMBERS
   @DomName('AudioNode.connect')
-  void connectNode(AudioNode destination, [int output = 0, int input = 0]) =>
-      _connect(destination, output, input);
+  void connectNode(AudioNode destination, [int output = 0, int input = 0]) {
+    _connect(destination, output, input);
+  }
 
   @DomName('AudioNode.connect')
-  void connectParam(AudioParam destination, [int output = 0]) =>
-      _connect(destination, output);
+  void connectParam(AudioParam destination, [int output = 0]) {
+    _connect(destination, output);
+  }
 }