Add <extensionview>

extensions/browser/guest_view/extension_view/extension_view_constants.cc

Index: extensions/browser/guest_view/extension_view/extension_view_constants.cc
diff --git a/extensions/browser/guest_view/extension_view/extension_view_constants.cc b/extensions/browser/guest_view/extension_view/extension_view_constants.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c2e182f2620f87d8e2ff1759af031de71fbafbc5
--- /dev/null
+++ b/extensions/browser/guest_view/extension_view/extension_view_constants.cc
@@ -0,0 +1,15 @@
+// Copyright 2015 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.
+
+#include "extensions/browser/guest_view/extension_view/extension_view_constants.h"
+
+namespace extensionview {
+
+// API namespace.
+extern const char kAPINamespace[] = "extensionViewInternal";
+
+// Attributes.
+const char kAttributeSrc[] = "src";
+
+}  // namespace extensionview