Update browser cache of accessibility tree on renderer sub-tree changes....

chrome/browser/renderer_host/render_view_host.cc

Index: chrome/browser/renderer_host/render_view_host.cc
===================================================================
--- chrome/browser/renderer_host/render_view_host.cc	(revision 57122)
+++ chrome/browser/renderer_host/render_view_host.cc	(working copy)
@@ -840,6 +840,8 @@
                         OnAccessibilityFocusChange)
     IPC_MESSAGE_HANDLER(ViewHostMsg_AccessibilityObjectStateChange,
                         OnAccessibilityObjectStateChange)
+    IPC_MESSAGE_HANDLER(ViewHostMsg_AccessibilityObjectChildrenChange,
+                        OnAccessibilityObjectChildrenChange)
     IPC_MESSAGE_HANDLER(ViewHostMsg_OnCSSInserted, OnCSSInserted)
     IPC_MESSAGE_HANDLER(ViewHostMsg_PageContents, OnPageContents)
     IPC_MESSAGE_HANDLER(ViewHostMsg_PageTranslated, OnPageTranslated)
@@ -1965,6 +1967,18 @@
   view()->OnAccessibilityObjectStateChange(acc_obj_id);
 }
 
+void RenderViewHost::OnAccessibilityObjectChildrenChange(
+    const std::vector<webkit_glue::WebAccessibility>& acc_changes) {
+  view()->OnAccessibilityObjectChildrenChange(acc_changes);
+
+  if (acc_changes.size() > 0) {
+    NotificationService::current()->Notify(
+        NotificationType::RENDER_VIEW_HOST_ACCESSIBILITY_TREE_UPDATED,
+        Source<RenderViewHost>(this),
+        NotificationService::NoDetails());
+  }
+}
+
 void RenderViewHost::OnAccessibilityTree(
     const webkit_glue::WebAccessibility& tree) {
   if (view())