Cross-process iframe accessibility.

content/browser/frame_host/render_frame_proxy_host.cc

 // Copyright 2014 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/frame_host/render_frame_proxy_host.h"
 
+#include "base/lazy_instance.h"
 #include "content/browser/frame_host/cross_process_frame_connector.h"
 #include "content/browser/frame_host/frame_tree.h"
 #include "content/browser/frame_host/frame_tree_node.h"
 #include "content/browser/frame_host/render_frame_host_impl.h"
 #include "content/browser/frame_host/render_widget_host_view_child_frame.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_view_base.h"
 #include "content/browser/site_instance_impl.h"
 #include "content/common/frame_messages.h"
+#include "content/public/browser/browser_thread.h"
 #include "ipc/ipc_message.h"
 
 namespace content {
 
+namespace {
+
+// The (process id, routing id) pair that identifies one RenderFrame.
+typedef std::pair<int32, int32> RenderFrameProxyHostID;
+typedef base::hash_map<RenderFrameProxyHostID, RenderFrameProxyHost*>
+    RoutingIDFrameProxyMap;
+base::LazyInstance<RoutingIDFrameProxyMap> g_routing_id_frame_proxy_map =
+  LAZY_INSTANCE_INITIALIZER;
+
+}
+
 RenderFrameProxyHost::RenderFrameProxyHost(SiteInstance* site_instance,
                                            FrameTreeNode* frame_tree_node)
     : routing_id_(site_instance->GetProcess()->GetNextRoutingID()),
       site_instance_(site_instance),
       frame_tree_node_(frame_tree_node) {
   GetProcess()->AddRoute(routing_id_, this);
+  g_routing_id_frame_proxy_map.Get().insert(std::make_pair(

[nasko, 2014/08/25 21:23:29]

nit: I like checking the return value of insert, just to make sure we don't have
any bugs creep up on us.

[dmazzoni, 2014/08/26 23:31:03]

Is this what you had in mind?

  DCHECK(g_routing_id_frame_proxy_map.Get().insert(
      std::make_pair(
          RenderFrameProxyHostID(GetProcess()->GetID(), routing_id_),
          this)).second);

[Charlie Reis, 2014/08/27 17:28:34]

You'll need to store the return value and DCHECK(result.second), since the
bodies of DCHECKs get compiled out.  For example:
https://code.google.com/p/chromium/codesearch#chromium/src/content/browser/fr...

+      RenderFrameProxyHostID(GetProcess()->GetID(), routing_id_), this));
 
   if (!frame_tree_node_->IsMainFrame() &&
       frame_tree_node_->parent()
               ->render_manager()
               ->current_frame_host()
               ->GetSiteInstance() == site_instance) {
     // The RenderFrameHost navigating cross-process is destroyed and a proxy for
     // it is created in the parent's process. CrossProcessFrameConnector
     // initialization only needs to happen on an initial cross-process
     // navigation, when the RenderFrameHost leaves the same process as its
     // parent. The same CrossProcessFrameConnector is used for subsequent cross-
     // process navigations, but it will be destroyed if the frame is
     // navigated back to the same SiteInstance as its parent.
     cross_process_frame_connector_.reset(new CrossProcessFrameConnector(this));
   }
 }
 
 RenderFrameProxyHost::~RenderFrameProxyHost() {
   if (GetProcess()->HasConnection())
     Send(new FrameMsg_DeleteProxy(routing_id_));
 
   GetProcess()->RemoveRoute(routing_id_);
+  g_routing_id_frame_proxy_map.Get().erase(
+      RenderFrameProxyHostID(GetProcess()->GetID(), routing_id_));
 }
 
 void RenderFrameProxyHost::SetChildRWHView(RenderWidgetHostView* view) {
   cross_process_frame_connector_->set_view(
       static_cast<RenderWidgetHostViewChildFrame*>(view));
 }
 
 RenderViewHostImpl* RenderFrameProxyHost::GetRenderViewHost() {
   if (render_frame_host_.get())
     return render_frame_host_->render_view_host();
@@ skipping 45 matching lines @@
 
   Send(new FrameMsg_NewFrameProxy(
       routing_id_,
       parent_routing_id,
       frame_tree_node_->frame_tree()->GetRenderViewHost(
           site_instance_)->GetRoutingID()));
 
   return true;
 }
 
+// static
+RenderFrameProxyHost* RenderFrameProxyHost::FromID(int process_id,

[nasko, 2014/08/25 21:23:29]

nit: static methods should be at the top of the file

[dmazzoni, 2014/08/26 23:31:03]

Done.

+                                                   int routing_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  RoutingIDFrameProxyMap* frames = g_routing_id_frame_proxy_map.Pointer();
+  RoutingIDFrameProxyMap::iterator it = frames->find(
+      RenderFrameProxyHostID(process_id, routing_id));
+  return it == frames->end() ? NULL : it->second;
+}
+
 }  // namespace content