Cross-process iframe accessibility.

content/common/accessibility_messages.h

 // 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.
 
 // IPC messages for accessibility.
 // Multiply-included message file, hence no include guard.
 
 #include "base/basictypes.h"
 #include "content/common/content_export.h"
 #include "content/common/view_message_enums.h"
@@ skipping 33 matching lines @@
   IPC_STRUCT_TRAITS_MEMBER(intlist_attributes)
   IPC_STRUCT_TRAITS_MEMBER(html_attributes)
   IPC_STRUCT_TRAITS_MEMBER(child_ids)
 IPC_STRUCT_TRAITS_END()
 
 IPC_STRUCT_TRAITS_BEGIN(ui::AXTreeUpdate)
   IPC_STRUCT_TRAITS_MEMBER(node_id_to_clear)
   IPC_STRUCT_TRAITS_MEMBER(nodes)
 IPC_STRUCT_TRAITS_END()
 
+typedef std::map<int32, int> FrameIDMap;
+
 IPC_STRUCT_BEGIN(AccessibilityHostMsg_EventParams)
   // The tree update.
   IPC_STRUCT_MEMBER(ui::AXTreeUpdate, update)
 
+  // Mapping from node id to frame routing id for an out-of-process iframe.

[Charlie Reis, 2014/08/21 19:23:27]

Are these frame routing IDs from RenderFrames or RenderFrameProxies?  (I would
expect the latter for OOPIFs, since we won't have RenderFrames for them.)

[dmazzoni, 2014/08/25 06:49:36]

Clarified.

I think it's useful to have both - you never know when a RenderFrame is going to
suddenly go out-of-process, and if we've already looked up the frame tree node
id on the browser side, we can work with it right away rather than waiting until
we get the notification of the RenderFrameProxy routing id.

+  IPC_STRUCT_MEMBER(FrameIDMap, frame_routing_ids)
+
   // Type of event.
   IPC_STRUCT_MEMBER(ui::AXEvent, event_type)
 
   // ID of the node that the event applies to.
   IPC_STRUCT_MEMBER(int, id)
 IPC_STRUCT_END()
 
 IPC_STRUCT_BEGIN(AccessibilityHostMsg_LocationChangeParams)
   // ID of the object whose location is changing.
   IPC_STRUCT_MEMBER(int, id)
@@ skipping 54 matching lines @@
 // Sent to notify the browser about renderer accessibility events.
 // The browser responds with a AccessibilityMsg_Events_ACK.
 IPC_MESSAGE_ROUTED1(
     AccessibilityHostMsg_Events,
     std::vector<AccessibilityHostMsg_EventParams>)
 
 // Sent to update the browser of the location of accessibility objects.
 IPC_MESSAGE_ROUTED1(
     AccessibilityHostMsg_LocationChanges,
     std::vector<AccessibilityHostMsg_LocationChangeParams>)