Cross-process iframe accessibility.

content/renderer/accessibility/renderer_accessibility_complete.cc

Index: content/renderer/accessibility/renderer_accessibility_complete.cc
diff --git a/content/renderer/accessibility/renderer_accessibility_complete.cc b/content/renderer/accessibility/renderer_accessibility_complete.cc
index 4a9de8f017da41809f384d46e687d5b1ba59dbc4..4b7ef8804feee7a92bd9d5b615c94df2ebb859c6 100644
--- a/content/renderer/accessibility/renderer_accessibility_complete.cc
+++ b/content/renderer/accessibility/renderer_accessibility_complete.cc
@@ -196,6 +196,9 @@ void RendererAccessibilityComplete::SendPendingAccessibilityEvents() {
     }
 
     AccessibilityHostMsg_EventParams event_msg;
+    tree_source_.CollectChildFrameIdMapping(

[ncarter (slow), 2014/05/02 19:10:02]

When the method SendPendingAccessibilityEvents returns, it seems that
tree_source_ will be left with two icky stack pointers into the corpse of
event_msg. Can we either give them a proper burial, or make the interface safer?

One possible solution would be to have the members of tree_source_ be maps (vs
map*'s) and after the maps are filled -- maybe at the end of SerializeChanges --
do a map::swap between the event_msg and the tree_source copies. That should be
as efficient, right?

+        &event_msg.guest_instance_ids,
+        &event_msg.frame_routing_ids);
     event_msg.event_type = event.event_type;
     event_msg.id = event.id;
     serializer_.SerializeChanges(obj, &event_msg.update);