Correctly update the bounds of objects in the accessibility tree.

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 2e72dde7fb93f06c9dc7286caa3fb991f9d2c826..e7765d4673e5af509c58a5cdbba4516e6d6aed1e 100644
--- a/content/renderer/accessibility/renderer_accessibility_complete.cc
+++ b/content/renderer/accessibility/renderer_accessibility_complete.cc
@@ -177,16 +177,21 @@ void RendererAccessibilityComplete::SendPendingAccessibilityEvents() {
   // Generate an event message from each Blink event.
   std::vector<AccessibilityHostMsg_EventParams> event_msgs;
 
+  // If there's a layout complete message, we need to send location changes.
+  bool had_layout_complete_messages = false;
+
   // Loop over each event and generate an updated event message.
   for (size_t i = 0; i < src_events.size(); ++i) {
-    AccessibilityHostMsg_EventParams& event =
-        src_events[i];
+    AccessibilityHostMsg_EventParams& event = src_events[i];
+    if (event.event_type == ui::AX_EVENT_LAYOUT_COMPLETE)
+      had_layout_complete_messages = true;
+
+    WebAXObject obj = document.accessibilityObjectFromID(event.id);
 
-    WebAXObject obj = document.accessibilityObjectFromID(
-        event.id);
     // Make sure the object still exists.
     if (!obj.updateBackingStoreAndCheckValidity())
       continue;
+
     // Make sure it's a descendant of our root node - exceptions include the
     // scroll area that's the parent of the main document (we ignore it), and
     // possibly nodes attached to a different document.
@@ -207,6 +212,13 @@ void RendererAccessibilityComplete::SendPendingAccessibilityEvents() {
     serializer_.SerializeChanges(obj, &event_msg.update);
     event_msgs.push_back(event_msg);
 
+    // For each node in the update, set the location in our map from
+    // ids to locations.
+    for (size_t i = 0; i < event_msg.update.nodes.size(); ++i) {
+      locations_[event_msg.update.nodes[i].id] =
+          event_msg.update.nodes[i].location;
+    }
+
     VLOG(0) << "Accessibility event: " << ui::ToString(event.event_type)
             << " on node id " << event_msg.id
             << "\n" << event_msg.update.ToString();
@@ -214,7 +226,8 @@ void RendererAccessibilityComplete::SendPendingAccessibilityEvents() {
 
   Send(new AccessibilityHostMsg_Events(routing_id(), event_msgs));
 
-  SendLocationChanges();
+  if (had_layout_complete_messages)
+    SendLocationChanges();
 }
 
 void RendererAccessibilityComplete::SendLocationChanges() {
@@ -246,6 +259,12 @@ void RendererAccessibilityComplete::SendLocationChanges() {
 
     // Save the new location.
     new_locations[id] = new_location;
+
+    // Explore children of this object.
+    std::vector<blink::WebAXObject> children;
+    tree_source_.GetChildren(obj, &children);
+    for (size_t i = 0; i < children.size(); ++i)
+      objs_to_explore.push(children[i]);
   }
   locations_.swap(new_locations);