Move extensions bindings code out of //chrome

chrome/renderer/extensions/document_custom_bindings.cc

-// 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.
-
-#include "chrome/renderer/extensions/document_custom_bindings.h"
-
-#include <string>
-
-#include "base/bind.h"
-#include "chrome/renderer/extensions/chrome_v8_context.h"
-#include "third_party/WebKit/public/web/WebDocument.h"
-#include "third_party/WebKit/public/web/WebFrame.h"
-#include "v8/include/v8.h"
-
-namespace extensions {
-
-DocumentCustomBindings::DocumentCustomBindings(
-    Dispatcher* dispatcher, ChromeV8Context* context)
-    : ChromeV8Extension(dispatcher, context) {
-  RouteFunction("RegisterElement",
-      base::Bind(&DocumentCustomBindings::RegisterElement,
-                 base::Unretained(this)));
-}
-
-// Attach an event name to an object.
-void DocumentCustomBindings::RegisterElement(
-    const v8::FunctionCallbackInfo<v8::Value>& args) {
-  if (args.Length() != 2 || !args[0]->IsString() || !args[1]->IsObject()) {
-    NOTREACHED();
-    return;
-  }
-
-  std::string element_name(*v8::String::Utf8Value(args[0]));
-  v8::Local<v8::Object> options = args[1]->ToObject();
-
-  blink::WebExceptionCode ec = 0;
-  blink::WebDocument document = context()->web_frame()->document();
-  v8::Handle<v8::Value> constructor =
-      document.registerEmbedderCustomElement(
-          blink::WebString::fromUTF8(element_name), options, ec);
-  args.GetReturnValue().Set(constructor);
-}
-
-}  // namespace extensions