One accessibility tree per frame.

content/browser/accessibility/accessibility_tree_formatter_blink.cc

 // Copyright (c) 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stddef.h>
 
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "content/browser/accessibility/accessibility_tree_formatter_blink.h"
 
@@ skipping 21 matching lines @@
     return node.PlatformGetChild(i);
   else
     return node.InternalGetChild(i);
 }
 
 void AccessibilityTreeFormatterBlink::AddProperties(
     const BrowserAccessibility& node,
     base::DictionaryValue* dict) {
   dict->SetInteger("id", node.GetId());
 
-  dict->SetString("role", ui::ToString(node.GetData().role));
+  dict->SetString("internalRole", ui::ToString(node.GetData().role));
 
   dict->SetInteger("boundsX", node.GetData().location.x());
   dict->SetInteger("boundsY", node.GetData().location.y());
   dict->SetInteger("boundsWidth", node.GetData().location.width());
   dict->SetInteger("boundsHeight", node.GetData().location.height());
 
   for (int state_index = ui::AX_STATE_NONE;
        state_index <= ui::AX_STATE_LAST;
        ++state_index) {
     auto state = static_cast<ui::AXState>(state_index);
@@ skipping 52 matching lines @@
     const base::DictionaryValue& dict) {
   base::string16 line;
 
   if (show_ids()) {
     int id_value;
     dict.GetInteger("id", &id_value);
     WriteAttribute(true, base::IntToString16(id_value), &line);
   }
 
   base::string16 role_value;
-  dict.GetString("role", &role_value);
+  dict.GetString("internalRole", &role_value);

[David Tseng, 2016/03/04 16:50:20]

Why this change?

[dmazzoni, 2016/03/07 21:35:32]

It conflicted with the string attribute "role" (which stores the ARIA role as
specified by the user). This was the first case where those didn't happen to
result in printing the same string in a test.

   WriteAttribute(true, base::UTF16ToUTF8(role_value), &line);
 
   for (int state_index = ui::AX_STATE_NONE;
        state_index <= ui::AX_STATE_LAST;
        ++state_index) {
     auto state = static_cast<ui::AXState>(state_index);
     const base::Value* value;
     if (!dict.Get(ui::ToString(state), &value))
       continue;
 
@@ skipping 84 matching lines @@
 
 const std::string AccessibilityTreeFormatterBlink::GetAllowString() {
   return "@BLINK-ALLOW:";
 }
 
 const std::string AccessibilityTreeFormatterBlink::GetDenyString() {
   return "@BLINK-DENY:";
 }
 
 }  // namespace content