Revert of Revert of DevTools: Introduce module initializers

Source/devtools/front_end/extensions/_module.js

Index: Source/devtools/front_end/extensions/_module.js
diff --git a/Source/devtools/front_end/extensions/_module.js b/Source/devtools/front_end/extensions/_module.js
new file mode 100644
index 0000000000000000000000000000000000000000..dca9d40732c993dd9ace658593f825271ee4979c
--- /dev/null
+++ b/Source/devtools/front_end/extensions/_module.js
@@ -0,0 +1,10 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+importScript("ExtensionAPI.js");
+importScript("ExtensionRegistryStub.js");
+importScript("ExtensionAuditCategory.js");
+importScript("ExtensionServer.js");
+importScript("ExtensionPanel.js");
+importScript("ExtensionView.js");