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

chrome/renderer/render_view.cc

Index: chrome/renderer/render_view.cc
===================================================================
--- chrome/renderer/render_view.cc	(revision 57122)
+++ chrome/renderer/render_view.cc	(working copy)
@@ -794,6 +794,8 @@
     IPC_MESSAGE_HANDLER(ViewMsg_SetAccessibilityFocus, OnSetAccessibilityFocus)
     IPC_MESSAGE_HANDLER(ViewMsg_AccessibilityDoDefaultAction,
                         OnAccessibilityDoDefaultAction)
+    IPC_MESSAGE_HANDLER(ViewMsg_AccessibilityObjectChildrenChange_ACK,
+                        OnAccessibilityObjectChildrenChangeAck)
     IPC_MESSAGE_HANDLER(ViewMsg_OpenFileSystemRequest_Complete,
                         OnOpenFileSystemRequestComplete)
 
@@ -1452,6 +1454,7 @@
     accessibility_->clear();
     accessibility_.reset();
   }
+  accessibility_changes_.clear();
 }
 
 // Tell the embedding application that the title of the active page has changed
@@ -4266,6 +4269,7 @@
     accessibility_->clear();
     accessibility_.reset(WebAccessibilityCache::create());
     accessibility_->initialize(webview());
+  accessibility_changes_.clear();
 
   WebAccessibilityObject src_tree = webview()->accessibilityObject();
   webkit_glue::WebAccessibility dst_tree(src_tree, accessibility_.get());
@@ -4295,6 +4299,19 @@
   }
 }
 
+void RenderView::OnAccessibilityObjectChildrenChangeAck() {
+  if (!accessibility_.get())
+    return;
+
+  if (!accessibility_changes_.empty()) {
+    Send(new ViewHostMsg_AccessibilityObjectChildrenChange(
+        routing_id_,
+        accessibility_changes_));
+  }
+
+  accessibility_changes_.clear();
+}
+
 void RenderView::OnGetAllSavableResourceLinksForCurrentPage(
     const GURL& page_url) {
   // Prepare list to storage all savable resource links.
@@ -5253,6 +5270,21 @@
 #endif
 }
 
+void RenderView::didChangeAccessibilityObjectChildren(
+    const WebKit::WebAccessibilityObject& acc_obj) {
+  if (!accessibility_.get())
+    return;
+
+  if (accessibility_changes_.empty()) {
+    Send(new ViewHostMsg_AccessibilityObjectChildrenChange(
+        routing_id_,
+        std::vector<webkit_glue::WebAccessibility>()));
+  }
+
+  accessibility_changes_.push_back(
+      webkit_glue::WebAccessibility(acc_obj, accessibility_.get()));
+}
+
 void RenderView::Print(WebFrame* frame, bool script_initiated) {
   DCHECK(frame);
   if (print_helper_.get() == NULL) {