Allow MimeHandlerViewGuest be embedded inside OOPIFs

content/browser/browser_plugin/browser_plugin_guest.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 "content/browser/browser_plugin/browser_plugin_guest.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
@@ skipping 118 matching lines @@
   // Create a RenderFrameProxyHost for the guest in the embedder renderer
   // process, so that the embedder can access the guest's window object.
   // On reattachment, we can reuse the same RenderFrameProxyHost because
   // the embedder process will always be the same even if the embedder
   // WebContents changes.
   //
   // TODO(fsamuel): Make sure this works for transferring guests across
   // owners in different processes. We probably need to clear the
   // |guest_proxy_routing_id_| and perform any necessary cleanup on Detach
   // to enable this.
-  SiteInstance* owner_site_instance = owner_web_contents_->GetSiteInstance();
-  int proxy_routing_id =
-      GetWebContents()->GetFrameTree()->root()->render_manager()->
-          CreateRenderFrameProxy(owner_site_instance);
+  SiteInstance* owner_site_instance = GetEmbedderFrame()->GetSiteInstance();
+  int proxy_routing_id = GetWebContents()
+                             ->GetFrameTree()
+                             ->root()
+                             ->render_manager()
+                             ->CreateRenderFrameProxy(owner_site_instance);

[nasko, 2016/10/27 21:03:40]

This doesn't seem right, as we take the SiteInstance from the frame, which might
not be the root, yet we create the proxy in the root frame. Shouldn't this be
GetEmbedderFrame()->frame_tree_node()->render_manager()->CreateRenderFrameProxy()?

[EhsanK, 2016/10/27 22:06:48]

This was my main question from you on this CL. Thanks for bringing it up!

This is what I understand so far:

1- We do create the RFPH in the root, but it is the root of the guest frame
tree. This way the RFP in the embedder frame's process can be used to post
message to the guest.
2- This would technically create the reverse path for post messaging, i.e., RFP
in guest process to message back (right?). However, calling this on the a frame
tree node which is not root and does not have a RenderViewHostImpl yet, will
cause a browser crash through CHECK:
https://cs.chromium.org/chromium/src/content/browser/frame_host/render_frame_...

So my question is, a) Is it OK to create RFPH in the node which is not main
frame given the context here: https://crbug.com/485520 and b) if yes, then how
can I do it? is it OK to remove the CHECK above?

[nasko, 2016/11/09 01:13:07]

I didn't realize at the time that GetEmbedderFrame() and GetWebContents() come
from two different frame trees. I think what you have is correct -
GetWebContents() will return the guest one, which needs a proxy in the embedder
process for it. So using the SiteInstance of the embedder frame is correct.

[EhsanK, 2016/11/15 19:54:22]

Acknowledged.

   guest_proxy_routing_id_ = RenderFrameProxyHost::FromID(
       owner_site_instance->GetProcess()->GetID(), proxy_routing_id)
           ->GetRenderViewHost()->GetRoutingID();
 
   return guest_proxy_routing_id_;
 }
 
 int BrowserPluginGuest::LoadURLWithParams(
     const NavigationController::LoadURLParams& load_params) {
   GetWebContents()->GetController().LoadURLWithParams(load_params);
@@ skipping 10 matching lines @@
 void BrowserPluginGuest::SizeContents(const gfx::Size& new_size) {
   GetWebContents()->GetView()->SizeContents(new_size);
 }
 
 void BrowserPluginGuest::WillDestroy() {
   is_in_destruction_ = true;
   owner_web_contents_ = nullptr;
   attached_ = false;
 }
 
+RenderFrameHostImpl* BrowserPluginGuest::GetEmbedderFrame() const {
+  return static_cast<RenderFrameHostImpl*>(delegate_->GetEmbedderFrame());
+}
+
 void BrowserPluginGuest::Init() {
   if (initialized_)
     return;
   initialized_ = true;
 
   // TODO(fsamuel): Initiailization prior to attachment should be behind a
   // command line flag once we introduce experimental guest types that rely on
   // this functionality.
   if (!delegate_->CanRunInDetachedState())
     return;
@@ skipping 52 matching lines @@
       static_cast<WebContentsImpl*>(delegate_->CreateNewGuestWindow(params));
   DCHECK(new_contents);
   return new_contents;
 }
 
 bool BrowserPluginGuest::OnMessageReceivedFromEmbedder(
     const IPC::Message& message) {
   RenderWidgetHostViewGuest* rwhv = static_cast<RenderWidgetHostViewGuest*>(
       web_contents()->GetRenderWidgetHostView());
   // Until the guest is attached, it should not be handling input events.
-  if (attached() && rwhv &&
-      rwhv->OnMessageReceivedFromEmbedder(
-          message,
-          RenderWidgetHostImpl::From(
-              embedder_web_contents()->GetRenderViewHost()->GetWidget()))) {
+  RenderFrameHostImpl* rfhi = GetEmbedderFrame();
+  RenderWidgetHostImpl* rwhi = rfhi ? rfhi->GetRenderWidgetHost() : nullptr;
+  if (attached() && rwhv && rwhi &&
+      rwhv->OnMessageReceivedFromEmbedder(message, rwhi)) {
     return true;
   }
 
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(BrowserPluginGuest, message)
     IPC_MESSAGE_HANDLER(BrowserPluginHostMsg_Detach, OnDetach)
     IPC_MESSAGE_HANDLER(BrowserPluginHostMsg_DragStatusUpdate,
                         OnDragStatusUpdate)
     IPC_MESSAGE_HANDLER(BrowserPluginHostMsg_ExecuteEditCommand,
                         OnExecuteEditCommand)
@@ skipping 107 matching lines @@
 }
 
 // static
 bool BrowserPluginGuest::IsGuest(RenderViewHostImpl* render_view_host) {
   return render_view_host && IsGuest(
       static_cast<WebContentsImpl*>(WebContents::FromRenderViewHost(
           render_view_host)));
 }
 
 RenderWidgetHostView* BrowserPluginGuest::GetOwnerRenderWidgetHostView() {
-  if (!owner_web_contents_)
-    return nullptr;
-  return owner_web_contents_->GetRenderWidgetHostView();
+  if (GetEmbedderFrame())
+    return GetEmbedderFrame()->GetView();
+
+  return nullptr;
 }
 
 void BrowserPluginGuest::UpdateVisibility() {
   OnSetVisibility(browser_plugin_instance_id(), visible());
 }
 
 BrowserPluginGuestManager*
 BrowserPluginGuest::GetBrowserPluginGuestManager() const {
   return GetWebContents()->GetBrowserContext()->GetGuestManager();
 }
@@ skipping 51 matching lines @@
 bool BrowserPluginGuest::HandleStopFindingForEmbedder(StopFindAction action) {
   return delegate_->HandleStopFindingForEmbedder(action);
 }
 
 void BrowserPluginGuest::ResendEventToEmbedder(
     const blink::WebInputEvent& event) {
   if (!attached() || !owner_web_contents_)
     return;
 
   DCHECK(browser_plugin_instance_id_);
-  RenderWidgetHostViewBase* view = static_cast<RenderWidgetHostViewBase*>(
-      embedder_web_contents()->GetMainFrame()->GetView());
+  RenderWidgetHostViewBase* view =
+      static_cast<RenderWidgetHostViewBase*>(GetOwnerRenderWidgetHostView());
 
   gfx::Vector2d offset_from_embedder = guest_window_rect_.OffsetFromOrigin();
   if (event.type == blink::WebInputEvent::GestureScrollUpdate) {
     blink::WebGestureEvent resent_gesture_event;
     memcpy(&resent_gesture_event, &event, sizeof(blink::WebGestureEvent));
     resent_gesture_event.x += offset_from_embedder.x();
     resent_gesture_event.y += offset_from_embedder.y();
     // Mark the resend source with the browser plugin's instance id, so the
     // correct browser_plugin will know to ignore the event.
     resent_gesture_event.resendingPluginId = browser_plugin_instance_id_;
@@ skipping 36 matching lines @@
   // in this case just queue any messages we receive.
   if (!attached() || !owner_web_contents_) {
     // Some pages such as data URLs, javascript URLs, and about:blank
     // do not load external resources and so they load prior to attachment.
     // As a result, we must save all these IPCs until attachment and then
     // forward them so that the embedder gets a chance to see and process
     // the load events.
     pending_messages_.push_back(std::move(msg));
     return;
   }
-  owner_web_contents_->Send(msg.release());
+
+  GetEmbedderFrame()->GetRenderWidgetHost()->Send(msg.release());
 }
 
 void BrowserPluginGuest::DragSourceEndedAt(int client_x, int client_y,
     int screen_x, int screen_y, blink::WebDragOperation operation) {
   web_contents()->GetRenderViewHost()->DragSourceEndedAt(client_x, client_y,
       screen_x, screen_y, operation);
   seen_embedder_drag_source_ended_at_ = true;
   EndSystemDragIfApplicable();
 }
 
@@ skipping 515 matching lines @@
           range, character_bounds);
 }
 #endif
 
 void BrowserPluginGuest::SetContextMenuPosition(const gfx::Point& position) {
   if (delegate_)
     delegate_->SetContextMenuPosition(position);
 }
 
 }  // namespace content