Make RenderFrame(Host) own a RenderWidget(Host).

content/common/frame_messages.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.
 
 // IPC messages for interacting with frames.
 // Multiply-included message file, hence no include guard.
 
 #include "content/common/content_export.h"
 #include "content/common/content_param_traits.h"
 #include "content/common/frame_message_enums.h"
@@ skipping 210 matching lines @@
 IPC_STRUCT_TRAITS_BEGIN(content::CommitNavigationParams)
   IPC_STRUCT_TRAITS_MEMBER(page_state)
   IPC_STRUCT_TRAITS_MEMBER(is_overriding_user_agent)
   IPC_STRUCT_TRAITS_MEMBER(browser_navigation_start)
 IPC_STRUCT_TRAITS_END()
 
 IPC_STRUCT_TRAITS_BEGIN(content::FrameReplicationState)
   IPC_STRUCT_TRAITS_MEMBER(origin)
 IPC_STRUCT_TRAITS_END()
 
+IPC_STRUCT_BEGIN(FrameMsg_NewFrame_WidgetParams)
+// Gives the routing ID for the RenderWidget that will be attached to the

[nasko, 2015/01/14 20:08:05]

Indent the struct body by two spaces, like the one below.

+// new RenderFrame. If the RenderFrame does not need a RenderWidget, this
+// is MSG_ROUTING_NONE and the other parameters are not read.
+IPC_STRUCT_MEMBER(int, routing_id)
+
+// Identifier for the output surface for the new RenderWidget.
+IPC_STRUCT_MEMBER(int, surface_id)
+
+// Tells the new RenderWidget whether it is initially hidden.
+IPC_STRUCT_MEMBER(bool, hidden)
+IPC_STRUCT_END()
+
 IPC_STRUCT_BEGIN(FrameMsg_Navigate_Params)
   // TODO(clamy): investigate which parameters are also needed in PlzNavigate
   // and move them to the appropriate NavigationParams struct.
 
   // These structs contain parameters shared by other navigation IPCs.
   IPC_STRUCT_MEMBER(content::CommonNavigationParams, common_params)
   IPC_STRUCT_MEMBER(content::RequestNavigationParams, request_params)
   IPC_STRUCT_MEMBER(content::CommitNavigationParams, commit_params)
 
   // The page_id for this navigation, or -1 if it is a new navigation.  Back,
@@ skipping 137 matching lines @@
                     unsigned /* action */)
 
 // Requests that the RenderFrame or RenderFrameProxy sets its opener to null.
 IPC_MESSAGE_ROUTED0(FrameMsg_DisownOpener)
 
 // Instructs the renderer to create a new RenderFrame object with |routing_id|.
 // The new frame should be created as a child of the object identified by
 // |parent_routing_id| or as top level if that is MSG_ROUTING_NONE.
 // If a valid |proxy_routing_id| is provided, the new frame will be configured
 // to replace the proxy on commit.
-IPC_MESSAGE_CONTROL3(FrameMsg_NewFrame,
+IPC_MESSAGE_CONTROL4(FrameMsg_NewFrame,
                      int /* routing_id */,
                      int /* parent_routing_id */,
-                     int /* proxy_routing_id */)
+                     int /* proxy_routing_id */,
+                     FrameMsg_NewFrame_WidgetParams /* widget_params */)
 
 // Instructs the renderer to create a new RenderFrameProxy object with
 // |routing_id|. The new proxy should be created as a child of the object
 // identified by |parent_routing_id| or as top level if that is
 // MSG_ROUTING_NONE.
 IPC_MESSAGE_CONTROL4(FrameMsg_NewFrameProxy,
                      int /* routing_id */,
                      int /* parent_routing_id */,
                      int /* render_view_routing_id */,
                      content::FrameReplicationState /* replication_state */)
@@ skipping 429 matching lines @@
 IPC_MESSAGE_ROUTED0(FrameHostMsg_DidFirstVisuallyNonEmptyPaint)
 
 #if defined(OS_MACOSX) || defined(OS_ANDROID)
 
 // Message to show/hide a popup menu using native controls.
 IPC_MESSAGE_ROUTED1(FrameHostMsg_ShowPopup,
                     FrameHostMsg_ShowPopup_Params)
 IPC_MESSAGE_ROUTED0(FrameHostMsg_HidePopup)
 
 #endif