Eliminate RenderFrameHost::GetInterfaceRegistry().

. Converts the last couple of use cases (extensions, usb browsertest)
  to using a WebContentsObserver.
. Removes the API.

[email protected]

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_site_isolation
Change-Id: I9da2be4ba4e20565fc6c2046c3db625b9729d1c8
Reviewed-on: https://chromium-review.googlesource.com/580391
Commit-Queue: Ben Goodger <[email protected]>
Reviewed-by: Ken Rockot <[email protected]>
Cr-Commit-Position: refs/heads/master@{#488852}
diff --git a/chrome/browser/extensions/chrome_extensions_interface_registration.h b/chrome/browser/extensions/chrome_extensions_interface_registration.h
new file mode 100644
index 0000000..4063703
--- /dev/null
+++ b/chrome/browser/extensions/chrome_extensions_interface_registration.h
@@ -0,0 +1,26 @@
+// 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.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_CHROME_EXTENSIONS_INTERFACE_REGISTRATION_H_
+#define CHROME_BROWSER_EXTENSIONS_CHROME_EXTENSIONS_INTERFACE_REGISTRATION_H_
+
+#include "services/service_manager/public/cpp/binder_registry.h"
+
+namespace content {
+class RenderFrameHost;
+}  // namespace content
+
+namespace extensions {
+
+class Extension;
+
+void RegisterChromeInterfacesForExtension(
+    service_manager::BinderRegistryWithArgs<content::RenderFrameHost*>*
+        registry,
+    content::RenderFrameHost* render_frame_host,
+    const Extension* extension);
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_CHROME_EXTENSIONS_INTERFACE_REGISTRATION_H_