Move extensions bindings code out of //chrome

chrome/renderer/extensions/blob_native_handler.h

-// Copyright 2013 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_RENDERER_EXTENSIONS_BLOB_NATIVE_HANDLER_H_
-#define CHROME_RENDERER_EXTENSIONS_BLOB_NATIVE_HANDLER_H_
-
-#include "extensions/renderer/object_backed_native_handler.h"
-
-namespace extensions {
-class ScriptContext;
-
-// This native handler is used to extract Blobs' UUIDs and pass them over to the
-// browser process extension implementation via argument modification. This is
-// necessary to support extension functions that take Blob parameters, as Blobs
-// are not serialized and sent over to the browser process in the normal way.
-//
-// Blobs sent via this method don't have their ref-counts incremented, so the
-// app using this technique must be sure to keep a reference.
-class BlobNativeHandler : public ObjectBackedNativeHandler {
- public:
-  explicit BlobNativeHandler(ScriptContext* context);
-};
-
-}  // namespace extensions
-
-#endif  // CHROME_RENDERER_EXTENSIONS_BLOB_NATIVE_HANDLER_H_