Make accessibility tree formatter walking ATK tree

ATK tree traversal makes the a11y tree formatter to produce ATK trees which makes accessible tree testing realistically reflect accessibility trees on Linux

Bug: 1066536
Change-Id: I03072c9bdd419202703308b7c79d65bb5e1e9e27
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2140306Reviewed-by: Martin Robinson <mrobinson@igalia.com>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: Alexander Surkkov <asurkov@igalia.com>
Cr-Commit-Position: refs/heads/master@{#757812}

content/browser/accessibility/accessibility_tree_formatter_auralinux.cc

@@ -27,7 +27,7 @@
 namespace content {
 
 class AccessibilityTreeFormatterAuraLinux
-    : public AccessibilityTreeFormatterBrowser {
+    : public AccessibilityTreeFormatterBase {
  public:
   AccessibilityTreeFormatterAuraLinux();
   ~AccessibilityTreeFormatterAuraLinux() override;
@@ -38,13 +38,13 @@ class AccessibilityTreeFormatterAuraLinux
   const std::string GetAllowString() override;
   const std::string GetDenyString() override;
   const std::string GetDenyNodeString() override;
-  void AddProperties(const BrowserAccessibility& node,
-                     base::DictionaryValue* dict) override;
 
   base::string16 ProcessTreeForOutput(
       const base::DictionaryValue& node,
       base::DictionaryValue* filtered_dict_result = nullptr) override;
 
+  std::unique_ptr<base::DictionaryValue> BuildAccessibilityTree(
+      BrowserAccessibility* root) override;
   std::unique_ptr<base::DictionaryValue> BuildAccessibilityTreeForProcess(
       base::ProcessId pid) override;
   std::unique_ptr<base::DictionaryValue> BuildAccessibilityTreeForWindow(
@@ -54,6 +54,13 @@ class AccessibilityTreeFormatterAuraLinux
   std::unique_ptr<base::DictionaryValue> BuildAccessibilityTreeWithNode(
       AtspiAccessible* node);
 
+  void RecursiveBuildAccessibilityTree(AtspiAccessible* node,
+                                       base::DictionaryValue* dict);
+  void RecursiveBuildAccessibilityTree(AtkObject*, base::DictionaryValue*);
+
+  void AddProperties(AtkObject*, base::DictionaryValue*);
+  void AddProperties(AtspiAccessible*, base::DictionaryValue*);
+
   void AddTextProperties(AtkText* atk_text, base::DictionaryValue* dict);
   void AddActionProperties(AtkObject* atk_object, base::DictionaryValue* dict);
   void AddValueProperties(AtkObject* atk_object, base::DictionaryValue* dict);
@@ -61,11 +68,6 @@ class AccessibilityTreeFormatterAuraLinux
   void AddTableCellProperties(const ui::AXPlatformNodeAuraLinux* node,
                               AtkObject* atk_object,
                               base::DictionaryValue* dict);
-
-  void RecursiveBuildAccessibilityTree(AtspiAccessible* node,
-                                       base::DictionaryValue* dict);
-  virtual void AddProperties(AtspiAccessible* node,
-                             base::DictionaryValue* dict);
 };
 
 // static
@@ -135,6 +137,24 @@ AccessibilityTreeFormatterAuraLinux::BuildAccessibilityTreeForPattern(
   return nullptr;
 }
 
+std::unique_ptr<base::DictionaryValue>
+AccessibilityTreeFormatterAuraLinux::BuildAccessibilityTree(
+    BrowserAccessibility* root) {
+  DCHECK(root);
+  DCHECK(root->instance_active());
+
+  BrowserAccessibilityAuraLinux* platform_root =
+      ToBrowserAccessibilityAuraLinux(root);
+  DCHECK(platform_root);
+
+  AtkObject* atk_root = platform_root->GetNativeViewAccessible();
+  DCHECK(atk_root);
+
+  std::unique_ptr<base::DictionaryValue> dict(new base::DictionaryValue);
+  RecursiveBuildAccessibilityTree(atk_root, dict.get());
+  return dict;
+}
+
 std::unique_ptr<base::DictionaryValue>
 AccessibilityTreeFormatterAuraLinux::BuildAccessibilityTreeForProcess(
     base::ProcessId pid) {
@@ -162,6 +182,32 @@ AccessibilityTreeFormatterAuraLinux::BuildAccessibilityTreeWithNode(
   return dict;
 }
 
+void AccessibilityTreeFormatterAuraLinux::RecursiveBuildAccessibilityTree(
+    AtkObject* atk_node,
+    base::DictionaryValue* dict) {
+  AddProperties(atk_node, dict);
+
+  auto child_count = atk_object_get_n_accessible_children(atk_node);
+  if (child_count <= 0)
+    return;
+
+  auto children = std::make_unique<base::ListValue>();
+  for (auto i = 0; i < child_count; i++) {
+    std::unique_ptr<base::DictionaryValue> child_dict(
+        new base::DictionaryValue);
+
+    AtkObject* atk_child = atk_object_ref_accessible_child(atk_node, i);
+    CHECK(atk_child);
+
+    RecursiveBuildAccessibilityTree(atk_child, child_dict.get());
+    g_object_unref(atk_child);
+
+    children->Append(std::move(child_dict));
+  }
+
+  dict->Set(kChildrenDictAttr, std::move(children));
+}
+
 void AccessibilityTreeFormatterAuraLinux::RecursiveBuildAccessibilityTree(
     AtspiAccessible* node,
     base::DictionaryValue* dict) {
@@ -412,18 +458,17 @@ void AccessibilityTreeFormatterAuraLinux::AddTableCellProperties(
 }
 
 void AccessibilityTreeFormatterAuraLinux::AddProperties(
-    const BrowserAccessibility& node,
+    AtkObject* atk_object,
     base::DictionaryValue* dict) {
-  dict->SetInteger("id", node.GetId());
-  BrowserAccessibilityAuraLinux* acc_obj =
-      ToBrowserAccessibilityAuraLinux(const_cast<BrowserAccessibility*>(&node));
-  DCHECK(acc_obj);
+  ui::AXPlatformNodeAuraLinux* platform_node =
+      ui::AXPlatformNodeAuraLinux::FromAtkObject(atk_object);
+  DCHECK(platform_node);
 
-  ui::AXPlatformNodeAuraLinux* ax_platform_node = acc_obj->GetNode();
-  DCHECK(ax_platform_node);
+  BrowserAccessibility* node = BrowserAccessibility::FromAXPlatformNodeDelegate(
+      platform_node->GetDelegate());
+  DCHECK(node);
 
-  AtkObject* atk_object = ax_platform_node->GetNativeViewAccessible();
-  DCHECK(atk_object);
+  dict->SetInteger("id", node->GetId());
 
   AtkRole role = atk_object_get_role(atk_object);
   if (role != ATK_ROLE_UNKNOWN) {
@@ -469,7 +514,7 @@ void AccessibilityTreeFormatterAuraLinux::AddProperties(
   AddActionProperties(atk_object, dict);
   AddValueProperties(atk_object, dict);
   AddTableProperties(atk_object, dict);
-  AddTableCellProperties(ax_platform_node, atk_object, dict);
+  AddTableCellProperties(platform_node, atk_object, dict);
 }
 
 void AccessibilityTreeFormatterAuraLinux::AddProperties(