Revert of Refactor content/renderer/accessibility to use AXTreeSerializer.

content/renderer/accessibility/renderer_accessibility_complete.h

Index: content/renderer/accessibility/renderer_accessibility_complete.h
diff --git a/content/renderer/accessibility/renderer_accessibility_complete.h b/content/renderer/accessibility/renderer_accessibility_complete.h
index 16eeeae5db631fc4f9c94cb2f625d9ce416fe99b..2511e3e89c2bfc4d82873e28f7381653e05bbd9b 100644
--- a/content/renderer/accessibility/renderer_accessibility_complete.h
+++ b/content/renderer/accessibility/renderer_accessibility_complete.h
@@ -11,12 +11,10 @@
 #include "base/containers/hash_tables.h"
 #include "base/memory/weak_ptr.h"
 #include "content/public/renderer/render_view_observer.h"
-#include "content/renderer/accessibility/blink_ax_tree_source.h"
 #include "content/renderer/accessibility/renderer_accessibility.h"
 #include "third_party/WebKit/public/web/WebAXEnums.h"
 #include "third_party/WebKit/public/web/WebAXObject.h"
 #include "ui/accessibility/ax_node_data.h"
-#include "ui/accessibility/ax_tree_serializer.h"
 
 namespace blink {
 class WebDocument;
@@ -52,6 +50,20 @@
 
   void HandleAXEvent(const blink::WebAXObject& obj, ui::AXEvent event);
 
+  // In order to keep track of what nodes the browser knows about, we keep a
+  // representation of the browser tree - just IDs and parent/child
+  // relationships.
+  struct CONTENT_EXPORT BrowserTreeNode {
+    BrowserTreeNode();
+    virtual ~BrowserTreeNode();
+    int32 id;
+    gfx::Rect location;
+    BrowserTreeNode* parent;
+    std::vector<BrowserTreeNode*> children;
+  };
+
+  virtual BrowserTreeNode* CreateBrowserTreeNode();
+
  protected:
   // Send queued events from the renderer to the browser.
   void SendPendingAccessibilityEvents();
@@ -62,6 +74,19 @@
   void SendLocationChanges();
 
  private:
+  // Serialize the given accessibility object |obj| and append it to
+  // |dst|, and then recursively also serialize any *new* children of
+  // |obj|, based on what object ids we know the browser already has.
+  // The set of ids serialized is added to |ids_serialized|, and any
+  // ids previously in that set are not serialized again.
+  void SerializeChangedNodes(const blink::WebAXObject& obj,
+                             std::vector<ui::AXNodeData>* dst,
+                             std::set<int>* ids_serialized);
+
+  // Clear the given node and recursively delete all of its descendants
+  // from the browser tree. (Does not delete |browser_node|).
+  void ClearBrowserTreeNode(BrowserTreeNode* browser_node);
+
   // Handlers for messages from the browser to the renderer.
   void OnDoDefaultAction(int acc_obj_id);
   void OnEventsAck();
@@ -82,6 +107,13 @@
       const blink::WebAXObject& src,
       ui::AXNodeData* dst);
 
+  // Build a tree of serializable ui::AXNodeData nodes to send to the
+  // browser process, given a WebAXObject node from Blink.
+  // Modifies |dst| in-place, it's assumed to be empty.
+  void BuildAccessibilityTree(const blink::WebAXObject& src,
+                              bool include_children,
+                              ui::AXNodeData* dst);
+
   // So we can queue up tasks to be executed later.
   base::WeakPtrFactory<RendererAccessibilityComplete> weak_factory_;
 
@@ -89,14 +121,11 @@
   // sent to the browser.
   std::vector<AccessibilityHostMsg_EventParams> pending_events_;
 
-  // The adapter that exposes Blink's accessibility tree to AXTreeSerializer.
-  BlinkAXTreeSource tree_source_;
+  // Our representation of the browser tree.
+  BrowserTreeNode* browser_root_;
 
-  // The serializer that sends accessibility messages to the browser process.
-  ui::AXTreeSerializer<blink::WebAXObject> serializer_;
-
-  // Current location of every object, so we can detect when it moves.
-  base::hash_map<int, gfx::Rect> locations_;
+  // A map from IDs to nodes in the browser tree.
+  base::hash_map<int32, BrowserTreeNode*> browser_id_map_;
 
   // The most recently observed scroll offset of the root document element.
   // TODO(dmazzoni): remove once https://bugs.webkit.org/show_bug.cgi?id=73460