Make <webview> use out-of-process iframe architecture.

extensions/renderer/guest_view/extensions_iframe_guest_view_container.cc

+// 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/renderer/guest_view/extensions_iframe_guest_view_container.h"
+
+#include "base/command_line.h"
+#include "components/guest_view/common/guest_view_messages.h"
+#include "content/public/common/content_switches.h"
+#include "content/public/renderer/render_frame.h"
+#include "extensions/common/guest_view/extensions_guest_view_messages.h"
+
+namespace extensions {
+
+ExtensionsIframeGuestViewContainer::ExtensionsIframeGuestViewContainer(
+    content::RenderFrame* render_frame)
+    : ExtensionsGuestViewContainer(render_frame), weak_ptr_factory_(this) {
+  CHECK(base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kSitePerProcess));
+  // There is no BrowserPluginDelegate to wait for.
+  ready_ = true;
+}
+
+ExtensionsIframeGuestViewContainer::~ExtensionsIframeGuestViewContainer() {
+}
+
+bool ExtensionsIframeGuestViewContainer::OnMessage(
+    const IPC::Message& message) {
+  // TODO(lazyboy): Do not send this message in --site-per-process.
+  if (message.type() == GuestViewMsg_GuestAttached::ID)
+    return true;
+
+  if (message.type() != ExtensionsGuestViewMsg_AttachToEmbedderFrame_ACK::ID)
+    return false;
+
+  OnHandleCallback(message);
+  return true;
+}
+
+}  // namespace extensions