cefclient: OSR accessibility enhancements (see issue #2604)

- Implement multi-tree support (e.g. page with iframes contains several trees)
- Implement OnAccessibilityLocationChange support
- Add scroll offset calculation
- Fix new Chromium tree layout parsing
- Fix uninitialized OsrAXNode::offset_container_id_
- Fix Windows non ascii AxName, AxValue, AxDescription representation

tests/cefclient/browser/browser_window_osr_gtk.cc

@@ -1362,6 +1362,11 @@ void BrowserWindowOsrGtk::UpdateAccessibilityTree(CefRefPtr<CefValue> value) {
   CEF_REQUIRE_UI_THREAD();
 }
 
+void BrowserWindowOsrGtk::UpdateAccessibilityLocation(
+    CefRefPtr<CefValue> value) {
+  CEF_REQUIRE_UI_THREAD();
+}
+
 void BrowserWindowOsrGtk::Create(ClientWindowHandle parent_handle) {
   REQUIRE_MAIN_THREAD();
   DCHECK(!glarea_);

tests/cefclient/browser/browser_window_osr_gtk.h

@@ -89,6 +89,7 @@ class BrowserWindowOsrGtk : public BrowserWindow,
       const CefRange& selection_range,
       const CefRenderHandler::RectList& character_bounds) OVERRIDE;
   void UpdateAccessibilityTree(CefRefPtr<CefValue> value) OVERRIDE;
+  void UpdateAccessibilityLocation(CefRefPtr<CefValue> value) OVERRIDE;
 
  private:
   ~BrowserWindowOsrGtk();

tests/cefclient/browser/browser_window_osr_mac.h

@@ -85,6 +85,7 @@ class BrowserWindowOsrMac : public BrowserWindow,
       const CefRenderHandler::RectList& character_bounds) OVERRIDE;
 
   void UpdateAccessibilityTree(CefRefPtr<CefValue> value) OVERRIDE;
+  void UpdateAccessibilityLocation(CefRefPtr<CefValue> value) OVERRIDE;
 
  private:
   // Create the NSView.

tests/cefclient/browser/browser_window_osr_mac.mm

@@ -109,6 +109,7 @@ CefTextInputClientOSRMac* GetInputClientFromContext(
               character_bounds:
                   (const CefRenderHandler::RectList&)character_bounds;
 - (void)UpdateAccessibilityTree:(CefRefPtr<CefValue>)value;
+- (void)UpdateAccessibilityLocation:(CefRefPtr<CefValue>)value;
 @end
 
 namespace {
@@ -1306,6 +1307,18 @@ NSPoint ConvertPointFromWindowToScreen(NSWindow* window, NSPoint point) {
   }
   return;
 }
+
+- (void)UpdateAccessibilityLocation:(CefRefPtr<CefValue>)value {
+  if (accessibility_helper_) {
+    accessibility_helper_->UpdateAccessibilityLocation(value);
+  }
+
+  if (accessibility_helper_) {
+    NSAccessibilityPostNotification(self,
+                                    NSAccessibilityValueChangedNotification);
+  }
+  return;
+}
 @end
 
 namespace client {

tests/cefclient/browser/client_handler_osr.cc

@@ -167,4 +167,12 @@ void ClientHandlerOsr::OnAccessibilityTreeChange(CefRefPtr<CefValue> value) {
   osr_delegate_->UpdateAccessibilityTree(value);
 }
 
+void ClientHandlerOsr::OnAccessibilityLocationChange(
+    CefRefPtr<CefValue> value) {
+  CEF_REQUIRE_UI_THREAD();
+  if (!osr_delegate_)
+    return;
+  osr_delegate_->UpdateAccessibilityLocation(value);
+}
+
 }  // namespace client

tests/cefclient/browser/client_handler_osr.h

@@ -68,6 +68,8 @@ class ClientHandlerOsr : public ClientHandler,
 
     virtual void UpdateAccessibilityTree(CefRefPtr<CefValue> value) = 0;
 
+    virtual void UpdateAccessibilityLocation(CefRefPtr<CefValue> value) = 0;
+
    protected:
     virtual ~OsrDelegate() {}
   };
@@ -130,7 +132,7 @@ class ClientHandlerOsr : public ClientHandler,
 
   // CefAccessibilityHandler methods.
   void OnAccessibilityTreeChange(CefRefPtr<CefValue> value) OVERRIDE;
-  void OnAccessibilityLocationChange(CefRefPtr<CefValue> value) OVERRIDE {}
+  void OnAccessibilityLocationChange(CefRefPtr<CefValue> value) OVERRIDE;
 
  private:
   // Only accessed on the UI thread.

tests/cefclient/browser/osr_accessibility_helper.cc

@@ -7,61 +7,180 @@
 
 namespace client {
 
+OsrAXTree::OsrAXTree() : parent_tree_id_(-1), root_node_id_(-1) {}
+
+OsrAXNode* OsrAXTree::GetNode(int nodeId) const {
+  auto result = node_map_.find(nodeId);
+  if (result != node_map_.end()) {
+    return result->second;
+  }
+  return NULL;
+}
+
+void OsrAXTree::EraseNode(int nodeId) {
+  node_map_.erase(nodeId);
+}
+
+void OsrAXTree::AddNode(OsrAXNode* node) {
+  node_map_[node->OsrAXNodeId()] = node;
+}
+
+void OsrAXTree::UpdateTreeData(CefRefPtr<CefDictionaryValue> value) {
+  if (value->HasKey("parent_tree_id")) {
+    parent_tree_id_ =
+        OsrAccessibilityHelper::CastToInt(value->GetValue("parent_tree_id"));
+  } else {
+    parent_tree_id_ = -1;
+  }
+
+  // may also update following:
+  // doctype, title, url, mimetype
+}
+
 OsrAccessibilityHelper::OsrAccessibilityHelper(CefRefPtr<CefValue> value,
                                                CefRefPtr<CefBrowser> browser)
-    : root_node_id_(-1), focused_node_id_(-1), browser_(browser) {
+    : root_tree_id_(-1),
+      focused_tree_id_(-1),
+      focused_node_id_(-1),
+      browser_(browser) {
   UpdateAccessibilityTree(value);
 }
 
+int OsrAccessibilityHelper::CastToInt(CefRefPtr<CefValue> value) {
+  if (value->GetType() == VTYPE_STRING) {
+    const std::string& str = value->GetString();
+    return atoi(str.c_str());
+  } else {
+    return value->GetInt();
+  }
+}
+
+void OsrAccessibilityHelper::UpdateAccessibilityLocation(
+    CefRefPtr<CefValue> value) {
+  if (!value || value->GetType() != VTYPE_LIST) {
+    return;
+  }
+
+  CefRefPtr<CefListValue> locationChangeList = value->GetList();
+  size_t locationChangeCount = locationChangeList->GetSize();
+  if (locationChangeCount == 0) {
+    return;
+  }
+
+  for (size_t i = 0; i < locationChangeCount; i++) {
+    CefRefPtr<CefDictionaryValue> locationChangeDict =
+        locationChangeList->GetDictionary(i);
+    if (!locationChangeDict->HasKey("ax_tree_id") ||
+        !locationChangeDict->HasKey("new_location") ||
+        !locationChangeDict->HasKey("id")) {
+      continue;
+    }
+    int treeId = CastToInt(locationChangeDict->GetValue("ax_tree_id"));
+    int nodeId = CastToInt(locationChangeDict->GetValue("id"));
+
+    CefRefPtr<CefDictionaryValue> newLocationDict =
+        locationChangeDict->GetDictionary("new_location");
+    if (!newLocationDict) {
+      continue;
+    }
+
+    OsrAXNode* node = GetNode(treeId, nodeId);
+    if (!node) {
+      continue;
+    }
+    node->UpdateLocation(newLocationDict);
+  }
+}
+
 void OsrAccessibilityHelper::UpdateAccessibilityTree(
     CefRefPtr<CefValue> value) {
-  if (value && value->GetType() == VTYPE_LIST) {
-    CefRefPtr<CefListValue> list = value->GetList();
-    size_t numEvents = list->GetSize();
-    if (numEvents > 0) {
-      for (size_t i = 0; i < numEvents; i++) {
-        CefRefPtr<CefDictionaryValue> event = list->GetDictionary(i);
-        if (event && event->HasKey("event_type") && event->HasKey("update")) {
-          std::string event_type = event->GetString("event_type");
+  if (!value || value->GetType() != VTYPE_DICTIONARY) {
+    return;
+  }
 
-          CefRefPtr<CefDictionaryValue> update = event->GetDictionary("update");
-          if (event_type == "layoutComplete")
-            UpdateLayout(update);
-          if (event_type == "focus" && event->HasKey("id")) {
-            // Update focused node id
-            focused_node_id_ = event->GetInt("id");
-            UpdateFocusedNode(update);
+  CefRefPtr<CefDictionaryValue> mainDict = value->GetDictionary();
+  if (!mainDict->HasKey("ax_tree_id") || !mainDict->HasKey("updates")) {
+    return;
+  }
+
+  int treeId = CastToInt(mainDict->GetValue("ax_tree_id"));
+  CefRefPtr<CefListValue> updatesList = mainDict->GetList("updates");
+
+  size_t updatesCount = updatesList->GetSize();
+  if (updatesCount == 0) {
+    return;
+  }
+
+  for (size_t i = 0; i < updatesCount; i++) {
+    CefRefPtr<CefDictionaryValue> updateDict = updatesList->GetDictionary(i);
+    UpdateLayout(treeId, updateDict);
   }
 }
+
+OsrAXNode* OsrAccessibilityHelper::GetRootNode() const {
+  return GetTreeRootNode(root_tree_id_);
 }
+
+OsrAXNode* OsrAccessibilityHelper::GetFocusedNode() const {
+  auto tree = accessibility_node_map_.find(focused_tree_id_);
+  if (tree != accessibility_node_map_.end()) {
+    return tree->second.GetNode(focused_node_id_);
   }
+
+  return NULL;
 }
+
+OsrAXNode* OsrAccessibilityHelper::GetTreeRootNode(int treeId) const {
+  auto tree = accessibility_node_map_.find(treeId);
+  if (tree != accessibility_node_map_.end()) {
+    return tree->second.GetNode(tree->second.GetRootNodeId());
+  }
+
+  return NULL;
 }
 
 void OsrAccessibilityHelper::UpdateLayout(
+    int treeId,
     CefRefPtr<CefDictionaryValue> update) {
-  if (update) {
-    CefRefPtr<CefDictionaryValue> tree_data;
-    // get tree data
-    if (update->HasKey("has_tree_data") && update->GetBool("has_tree_data"))
-      tree_data = update->GetDictionary("tree_data");
+  if (!update) {
+    return;
+  }
 
   // If a node is to be cleared
   if (update->HasKey("node_id_to_clear")) {
-      int node_id_to_clear = update->GetInt("node_id_to_clear");
+    int nodeId = CastToInt(update->GetValue("node_id_to_clear"));
 
     // reset root node if that is to be cleared
-      if (node_id_to_clear == root_node_id_)
-        root_node_id_ = -1;
-      OsrAXNode* node = GetNode(node_id_to_clear);
+    auto tree = accessibility_node_map_.find(treeId);
+    if (tree != accessibility_node_map_.end()) {
+      if (tree->second.GetRootNodeId() == nodeId) {
+        root_tree_id_ = -1;
+        tree->second.SetRootNodeId(-1);
+      }
+    }
+    if ((focused_tree_id_ == treeId) && (focused_node_id_ == nodeId)) {
+      UpdateFocusedNode(-1, -1);
+    }
+    OsrAXNode* node = GetNode(treeId, nodeId);
     DestroyNode(node);
   }
 
-    if (update->HasKey("root_id"))
-      root_node_id_ = update->GetInt("root_id");
+  // get tree data
+  if (update->HasKey("tree_data") && update->HasKey("has_tree_data") &&
+      update->GetBool("has_tree_data")) {
+    CefRefPtr<CefDictionaryValue> tree_data =
+        update->GetDictionary("tree_data");
+    auto& tree = accessibility_node_map_[treeId];
+    tree.UpdateTreeData(tree_data);
+    if (tree.GetParentTreeId() == -1) {
+      root_tree_id_ = treeId;
+    }
+    if (tree_data->HasKey("focus_id") && tree_data->HasKey("focused_tree_id")) {
+      UpdateFocusedNode(CastToInt(tree_data->GetValue("focused_tree_id")),
+                        CastToInt(tree_data->GetValue("focus_id")));
+    }
+  }
 
-    if (tree_data && tree_data->HasKey("focus_id"))
-      focused_node_id_ = tree_data->GetInt("focus_id");
   // Now initialize/update the node data.
   if (update->HasKey("nodes")) {
     CefRefPtr<CefListValue> nodes = update->GetList("nodes");
@@ -69,72 +188,79 @@ void OsrAccessibilityHelper::UpdateLayout(
     for (size_t index = 0; index < nodes->GetSize(); index++) {
       CefRefPtr<CefDictionaryValue> node = nodes->GetDictionary(index);
       if (node) {
-          int node_id = node->GetInt("id");
-          OsrAXNode* axNode = GetNode(node_id);
+        auto& tree = accessibility_node_map_[treeId];
+        int nodeId = CastToInt(node->GetValue("id"));
+        OsrAXNode* axNode = tree.GetNode(nodeId);
         // Create if it is a new one
         if (axNode) {
           axNode->UpdateValue(node);
         } else {
-            axNode = OsrAXNode::CreateNode(node, this);
-            accessibility_node_map_[node_id] = axNode;
-          }
-        }
+          axNode = OsrAXNode::CreateNode(treeId, nodeId, node, this);
+          tree.AddNode(axNode);
         }
       }
     }
   }
 
-void OsrAccessibilityHelper::UpdateFocusedNode(
-    CefRefPtr<CefDictionaryValue> update) {
-  if (update && update->HasKey("nodes")) {
-    CefRefPtr<CefListValue> nodes = update->GetList("nodes");
+  if (update->HasKey("root_id")) {
+    int nodeId = CastToInt(update->GetValue("root_id"));
+    OsrAXNode* node = GetNode(treeId, nodeId);
+    if (node != NULL) {
+      auto& tree = accessibility_node_map_[treeId];
+      tree.SetRootNodeId(nodeId);
+    }
+  }
+}
 
-    for (size_t index = 0; index < nodes->GetSize(); index++) {
-      CefRefPtr<CefDictionaryValue> node = nodes->GetDictionary(index);
-      if (node) {
-        int node_id = node->GetInt("id");
-        OsrAXNode* axNode = GetNode(node_id);
-        // Create if it is a new one
-        if (axNode) {
-          axNode->UpdateValue(node);
-        } else {
-          axNode = OsrAXNode::CreateNode(node, this);
-          accessibility_node_map_[node_id] = axNode;
-        }
-      }
-    }
+void OsrAccessibilityHelper::UpdateFocusedNode(int treeId, int nodeId) {
+  if ((focused_tree_id_ == treeId) && (focused_node_id_ == nodeId)) {
+    return;
   }
+  focused_tree_id_ = treeId;
+  focused_node_id_ = nodeId;
+
   // Now Notify Screen Reader
   OsrAXNode* axNode = GetFocusedNode();
-  // Fallback to Root
-  if (!axNode)
-    axNode = GetRootNode();
-
+  if (axNode) {
     axNode->NotifyAccessibilityEvent("focus");
   }
+}
 
 void OsrAccessibilityHelper::Reset() {
   accessibility_node_map_.clear();
-  root_node_id_ = focused_node_id_ = -1;
+  root_tree_id_ = -1;
+  focused_tree_id_ = focused_node_id_ = -1;
 }
 
 void OsrAccessibilityHelper::DestroyNode(OsrAXNode* node) {
   if (node) {
+    int treeId = node->OsrAXTreeId();
     int numChilds = node->GetChildCount();
     if (numChilds > 0) {
       for (int i = 0; i < numChilds; i++) {
-        DestroyNode(node->ChildAtIndex(i));
+        OsrAXNode* childNode = node->ChildAtIndex(i);
+        if (!childNode) {
+          continue;
+        }
+        childNode->SetParent(NULL);
+        if (childNode->OsrAXTreeId() == treeId) {
+          DestroyNode(childNode);
         }
       }
-    accessibility_node_map_.erase(node->OsrAXNodeId());
+    }
+    auto tree = accessibility_node_map_.find(treeId);
+    if (tree != accessibility_node_map_.end()) {
+      tree->second.EraseNode(node->OsrAXNodeId());
+    }
+
     node->Destroy();
   }
 }
 
-OsrAXNode* OsrAccessibilityHelper::GetNode(int nodeId) const {
-  if (nodeId != -1 &&
-      accessibility_node_map_.find(nodeId) != accessibility_node_map_.end()) {
-    return accessibility_node_map_.at(nodeId);
+OsrAXNode* OsrAccessibilityHelper::GetNode(int treeId, int nodeId) const {
+  auto tree = accessibility_node_map_.find(treeId);
+  if (tree != accessibility_node_map_.end()) {
+    return tree->second.GetNode(nodeId);
   }
 
   return NULL;

tests/cefclient/browser/osr_accessibility_helper.h

@@ -12,6 +12,24 @@
 namespace client {
 
 class OsrAXNode;
+class OsrAccessibilityHelper;
+
+class OsrAXTree {
+ public:
+  OsrAXTree();
+  OsrAXNode* GetNode(int nodeId) const;
+  void EraseNode(int nodeId);
+  void UpdateTreeData(CefRefPtr<CefDictionaryValue> value);
+  void AddNode(OsrAXNode* node);
+  int GetParentTreeId() const { return parent_tree_id_; }
+  int GetRootNodeId() const { return root_node_id_; }
+  void SetRootNodeId(int nodeId) { root_node_id_ = nodeId; }
+
+ private:
+  int parent_tree_id_;
+  int root_node_id_;
+  std::map<int, OsrAXNode*> node_map_;
+};
 
 // Helper class that abstracts Renderer Accessibility tree and provides a
 // uniform interface to be consumed by IAccessible interface on Windows and
@@ -23,9 +41,11 @@ class OsrAccessibilityHelper {
 
   void UpdateAccessibilityTree(CefRefPtr<CefValue> value);
 
-  OsrAXNode* GetRootNode() const { return GetNode(root_node_id_); }
+  void UpdateAccessibilityLocation(CefRefPtr<CefValue> value);
 
-  OsrAXNode* GetFocusedNode() const { return GetNode(focused_node_id_); }
+  OsrAXNode* GetRootNode() const;
+
+  OsrAXNode* GetFocusedNode() const;
 
   CefWindowHandle GetWindowHandle() const {
     return browser_->GetHost()->GetWindowHandle();
@@ -33,23 +53,26 @@ class OsrAccessibilityHelper {
 
   CefRefPtr<CefBrowser> GetBrowser() const { return browser_; }
 
-  OsrAXNode* GetNode(int nodeId) const;
+  OsrAXNode* GetNode(int treeId, int nodeId) const;
+
+  OsrAXNode* GetTreeRootNode(int treeId) const;
+
+  static int CastToInt(CefRefPtr<CefValue> value);
 
  private:
-  OsrAXNode* CreateNode(OsrAXNode* parent, CefRefPtr<CefDictionaryValue> value);
-
   void Reset();
 
-  void UpdateLayout(CefRefPtr<CefDictionaryValue> update);
+  void UpdateLayout(int treeId, CefRefPtr<CefDictionaryValue> update);
 
-  void UpdateFocusedNode(CefRefPtr<CefDictionaryValue> update);
+  void UpdateFocusedNode(int treeId, int nodeId);
 
   // Destroy the node and remove from Map
   void DestroyNode(OsrAXNode* node);
-  int root_node_id_;
+  int root_tree_id_;
+  int focused_tree_id_;
   int focused_node_id_;
   CefRefPtr<CefBrowser> browser_;
-  std::map<int, OsrAXNode*> accessibility_node_map_;
+  std::map<int, OsrAXTree> accessibility_node_map_;
 };
 
 }  // namespace client

tests/cefclient/browser/osr_accessibility_node.cc

@@ -11,19 +11,37 @@
 
 namespace client {
 
-OsrAXNode::OsrAXNode(CefRefPtr<CefDictionaryValue> value,
+OsrAXNode::OsrAXNode(int treeId,
+                     int nodeId,
+                     CefRefPtr<CefDictionaryValue> value,
                      OsrAccessibilityHelper* helper)
-    : node_id_(-1),
+    : tree_id_(treeId),
+      node_id_(nodeId),
+      child_tree_id_(-1),
       platform_accessibility_(NULL),
       parent_(NULL),
+      offset_container_id_(-1),
       accessibility_helper_(helper) {
   UpdateValue(value);
 }
 
-void OsrAXNode::UpdateValue(CefRefPtr<CefDictionaryValue> value) {
-  if (value && value->HasKey("id")) {
-    node_id_ = value->GetInt("id");
+void OsrAXNode::UpdateLocation(CefRefPtr<CefDictionaryValue> value) {
+  // Update Bounds
+  if (value->HasKey("bounds")) {
+    CefRefPtr<CefDictionaryValue> loc = value->GetDictionary("bounds");
+    if (loc) {
+      location_ = CefRect(loc->GetDouble("x"), loc->GetDouble("y"),
+                          loc->GetDouble("width"), loc->GetDouble("height"));
+    }
+  }
+  // Update offsets
+  if (value->HasKey("offset_container_id")) {
+    offset_container_id_ = OsrAccessibilityHelper::CastToInt(
+        value->GetValue("offset_container_id"));
+  }
+}
 
+void OsrAXNode::UpdateValue(CefRefPtr<CefDictionaryValue> value) {
   if (value->HasKey("role"))
     role_ = value->GetString("role");
 
@@ -32,7 +50,8 @@ void OsrAXNode::UpdateValue(CefRefPtr<CefDictionaryValue> value) {
     // Reset child Ids
     child_ids_.clear();
     for (size_t idx = 0; idx < childs->GetSize(); idx++)
-        child_ids_.push_back(childs->GetInt(idx));
+      child_ids_.push_back(
+          OsrAccessibilityHelper::CastToInt(childs->GetValue(idx)));
   }
   // Update Location
   if (value->HasKey("location")) {
@@ -44,12 +63,30 @@ void OsrAXNode::UpdateValue(CefRefPtr<CefDictionaryValue> value) {
   }
   // Update offsets
   if (value->HasKey("offset_container_id")) {
-      offset_container_id_ = value->GetInt("offset_container_id");
+    offset_container_id_ = OsrAccessibilityHelper::CastToInt(
+        value->GetValue("offset_container_id"));
   }
   // Update attributes
   if (value->HasKey("attributes")) {
+    child_tree_id_ = -1;
+
     attributes_ = value->GetDictionary("attributes");
 
+    if (attributes_) {
+      scroll_.x = attributes_->HasKey("scrollX")
+                      ? OsrAccessibilityHelper::CastToInt(
+                            attributes_->GetValue("scrollX"))
+                      : 0;
+      scroll_.y = attributes_->HasKey("scrollY")
+                      ? OsrAccessibilityHelper::CastToInt(
+                            attributes_->GetValue("scrollY"))
+                      : 0;
+    }
+
+    if (attributes_ && attributes_->HasKey("childTreeId")) {
+      child_tree_id_ = OsrAccessibilityHelper::CastToInt(
+          attributes_->GetValue("childTreeId"));
+    }
     if (attributes_ && attributes_->HasKey("name"))
       name_ = attributes_->GetString("name");
     if (attributes_ && attributes_->HasKey("value"))
@@ -58,7 +95,6 @@ void OsrAXNode::UpdateValue(CefRefPtr<CefDictionaryValue> value) {
       description_ = attributes_->GetString("description");
   }
 }
-}
 
 CefWindowHandle OsrAXNode::GetWindowHandle() const {
   if (accessibility_helper_)
@@ -78,8 +114,21 @@ void OsrAXNode::SetParent(OsrAXNode* parent) {
 
 CefRect OsrAXNode::AxLocation() const {
   CefRect loc = location_;
-  OsrAXNode* offsetNode = accessibility_helper_->GetNode(offset_container_id_);
-  // Add offset from parent Lcoation
+  loc.x -= scroll_.x;
+  loc.y -= scroll_.y;
+  OsrAXNode* offsetNode =
+      accessibility_helper_->GetNode(OsrAXTreeId(), offset_container_id_);
+  if (!offsetNode) {
+    OsrAXNode* p = parent_;
+    while (p) {
+      if (p->OsrAXTreeId() != OsrAXTreeId()) {
+        offsetNode = p;
+        break;
+      }
+      p = p->parent_;
+    }
+  }
+  // Add offset from parent Location
   if (offsetNode) {
     CefRect offset = offsetNode->AxLocation();
     loc.x += offset.x;
@@ -88,17 +137,39 @@ CefRect OsrAXNode::AxLocation() const {
   return loc;
 }
 
+int OsrAXNode::GetChildCount() const {
+  int count = static_cast<int>(child_ids_.size());
+  if (child_tree_id_ >= 0) {
+    OsrAXNode* childTreeRootNode =
+        accessibility_helper_->GetTreeRootNode(child_tree_id_);
+    if (childTreeRootNode) {
+      count++;
+    }
+  }
+  return count;
+}
+
 OsrAXNode* OsrAXNode::ChildAtIndex(int index) const {
-  if (index < GetChildCount())
-    return accessibility_helper_->GetNode(child_ids_[index]);
-  else
+  int count = static_cast<int>(child_ids_.size());
+  if (index < count)
+    return accessibility_helper_->GetNode(OsrAXTreeId(), child_ids_[index]);
+  if ((index == count) && (child_tree_id_ >= 0)) {
+    OsrAXNode* childTreeRootNode =
+        accessibility_helper_->GetTreeRootNode(child_tree_id_);
+    if (childTreeRootNode) {
+      return childTreeRootNode;
+    }
+  }
+
   return NULL;
 }
 
 // Create and return the platform specific OsrAXNode Object
-OsrAXNode* OsrAXNode::CreateNode(CefRefPtr<CefDictionaryValue> value,
+OsrAXNode* OsrAXNode::CreateNode(int treeId,
+                                 int nodeId,
+                                 CefRefPtr<CefDictionaryValue> value,
                                  OsrAccessibilityHelper* helper) {
-  return new OsrAXNode(value, helper);
+  return new OsrAXNode(treeId, nodeId, value, helper);
 }
 
 }  // namespace client

tests/cefclient/browser/osr_accessibility_node.h

@@ -33,12 +33,17 @@ class OsrAccessibilityHelper;
 class OsrAXNode {
  public:
   // Create and return the platform specific OsrAXNode Object.
-  static OsrAXNode* CreateNode(CefRefPtr<CefDictionaryValue> value,
+  static OsrAXNode* CreateNode(int treeId,
+                               int nodeId,
+                               CefRefPtr<CefDictionaryValue> value,
                                OsrAccessibilityHelper* helper);
 
   // Update Value.
   void UpdateValue(CefRefPtr<CefDictionaryValue> value);
 
+  // UpdateLocation
+  void UpdateLocation(CefRefPtr<CefDictionaryValue> value);
+
   // Fire a platform-specific notification that an event has occurred on
   // this object.
   void NotifyAccessibilityEvent(std::string event_type) const;
@@ -58,13 +63,15 @@ class OsrAXNode {
     return accessibility_helper_;
   }
 
-  int GetChildCount() const { return static_cast<int>(child_ids_.size()); }
+  int GetChildCount() const;
 
   // Return the Child at the specified index
   OsrAXNode* ChildAtIndex(int index) const;
 
   const CefString& AxRole() const { return role_; }
 
+  int OsrAXTreeId() const { return tree_id_; }
+
   int OsrAXNodeId() const { return node_id_; }
 
   const CefString& AxValue() const { return value_; }
@@ -82,15 +89,20 @@ class OsrAXNode {
   void SetParent(OsrAXNode* parent);
 
  protected:
-  OsrAXNode(CefRefPtr<CefDictionaryValue> value,
+  OsrAXNode(int treeId,
+            int nodeId,
+            CefRefPtr<CefDictionaryValue> value,
             OsrAccessibilityHelper* helper);
 
+  int tree_id_;
   int node_id_;
+  int child_tree_id_;
   CefString role_;
   CefString value_;
   CefString name_;
   CefString description_;
   CefRect location_;
+  CefPoint scroll_;
   std::vector<int> child_ids_;
   CefNativeAccessible* platform_accessibility_;
   OsrAXNode* parent_;

tests/cefclient/browser/osr_accessibility_node_win.cc

@@ -347,7 +347,7 @@ STDMETHODIMP CefIAccessible::get_accName(VARIANT varChild, BSTR* pszName) {
   HRESULT retCode = DATACHECK(node_);
   if (SUCCEEDED(retCode)) {
     if (pszName && VALID_CHILDID(varChild)) {
-      std::string name = node_->AxName();
+      std::wstring name = node_->AxName();
       CComBSTR bstrResult(name.c_str());
       *pszName = bstrResult.Detach();
     }
@@ -362,7 +362,7 @@ STDMETHODIMP CefIAccessible::get_accValue(VARIANT varChild, BSTR* pszValue) {
   HRESULT retCode = DATACHECK(node_);
   if (SUCCEEDED(retCode)) {
     if (pszValue && VALID_CHILDID(varChild)) {
-      std::string name = node_->AxValue();
+      std::wstring name = node_->AxValue();
       CComBSTR bstrResult(name.c_str());
       *pszValue = bstrResult.Detach();
     }
@@ -378,7 +378,7 @@ STDMETHODIMP CefIAccessible::get_accDescription(VARIANT varChild,
   HRESULT retCode = DATACHECK(node_);
   if (SUCCEEDED(retCode)) {
     if (pszDescription && VALID_CHILDID(varChild)) {
-      std::string name = node_->AxDescription();
+      std::wstring name = node_->AxDescription();
       CComBSTR bstrResult(name.c_str());
       *pszDescription = bstrResult.Detach();
     }

tests/cefclient/browser/osr_window_win.cc

@@ -1058,6 +1058,16 @@ void OsrWindowWin::UpdateAccessibilityTree(CefRefPtr<CefValue> value) {
 #endif  // defined(CEF_USE_ATL)
 }
 
+void OsrWindowWin::UpdateAccessibilityLocation(CefRefPtr<CefValue> value) {
+  CEF_REQUIRE_UI_THREAD();
+
+#if defined(CEF_USE_ATL)
+  if (accessibility_handler_) {
+    accessibility_handler_->UpdateAccessibilityLocation(value);
+  }
+#endif  // defined(CEF_USE_ATL)
+}
+
 #if defined(CEF_USE_ATL)
 
 CefBrowserHost::DragOperationsMask OsrWindowWin::OnDragEnter(

tests/cefclient/browser/osr_window_win.h

@@ -146,7 +146,9 @@ class OsrWindowWin
       const CefRange& selection_range,
       const CefRenderHandler::RectList& character_bounds) OVERRIDE;
 
-  void UpdateAccessibilityTree(CefRefPtr<CefValue> value);
+  void UpdateAccessibilityTree(CefRefPtr<CefValue> value) OVERRIDE;
+
+  void UpdateAccessibilityLocation(CefRefPtr<CefValue> value) OVERRIDE;
 
 #if defined(CEF_USE_ATL)
   // OsrDragEvents methods.