[Extensions] Begin making Extension port initialization asynchronous

chrome/renderer/extensions/tabs_custom_bindings.cc

-// Copyright (c) 2012 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/tabs_custom_bindings.h"
-
-#include <stdint.h>
-
-#include <string>
-
-#include "base/bind.h"
-#include "base/metrics/histogram_macros.h"
-#include "content/public/renderer/render_frame.h"
-#include "extensions/common/extension_messages.h"
-#include "extensions/renderer/script_context.h"
-#include "v8/include/v8.h"
-
-namespace extensions {
-
-TabsCustomBindings::TabsCustomBindings(ScriptContext* context)
-    : ObjectBackedNativeHandler(context) {
-  RouteFunction("OpenChannelToTab", "tabs",
-                base::Bind(&TabsCustomBindings::OpenChannelToTab,
-                           base::Unretained(this)));
-}
-
-void TabsCustomBindings::OpenChannelToTab(
-    const v8::FunctionCallbackInfo<v8::Value>& args) {
-  content::RenderFrame* render_frame = context()->GetRenderFrame();
-  if (!render_frame)
-    return;
-
-  // tabs_custom_bindings.js unwraps arguments to tabs.connect/sendMessage and
-  // passes them to OpenChannelToTab, in the following order:
-  // - |tab_id| - Positive number that specifies the destination of the channel.
-  // - |frame_id| - Target frame(s) in the tab where onConnect is dispatched:
-  //   -1 for all frames, 0 for the main frame, >0 for a child frame.
-  // - |extension_id| - Extension ID of sender and destination.
-  // - |channel_name| - A user-defined channel name.
-  CHECK(args.Length() >= 4 &&
-        args[0]->IsInt32() &&
-        args[1]->IsInt32() &&
-        args[2]->IsString() &&
-        args[3]->IsString());
-
-  ExtensionMsg_TabTargetConnectionInfo info;
-  info.tab_id = args[0]->Int32Value();
-  info.frame_id = args[1]->Int32Value();
-  std::string extension_id = *v8::String::Utf8Value(args[2]);
-  std::string channel_name = *v8::String::Utf8Value(args[3]);
-  int port_id = -1;
-  {
-    SCOPED_UMA_HISTOGRAM_TIMER("Extensions.Messaging.GetPortIdSyncTime.Tab");
-    render_frame->Send(new ExtensionHostMsg_OpenChannelToTab(
-        render_frame->GetRoutingID(), info, extension_id, channel_name,
-        &port_id));
-  }
-  args.GetReturnValue().Set(static_cast<int32_t>(port_id));
-}
-
-}  // namespace extensions