Support presentational iframes and make use of them in the uber frame.

content/browser/accessibility/browser_accessibility.cc

 // Copyright (c) 2012 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 "content/browser/accessibility/browser_accessibility.h"
 
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 660 matching lines @@
   }
 
   // Note: WebAXStateReadonly being false means it's either a text control,
   // or contenteditable. We also check for editable text roles to cover
   // another element that has role=textbox set on it.
   return (!HasState(ui::AX_STATE_READ_ONLY) ||
           GetRole() == ui::AX_ROLE_TEXT_FIELD ||
           GetRole() == ui::AX_ROLE_TEXT_AREA);
 }
 
+bool BrowserAccessibility::IsWebAreaForPresentationalIframe() const {
+  if (GetRole() != ui::AX_ROLE_WEB_AREA &&
+      GetRole() != ui::AX_ROLE_ROOT_WEB_AREA) {
+    return false;
+  }
+
+  BrowserAccessibility* parent = GetParent();
+  if (!parent)
+    return false;
+
+  BrowserAccessibility* grandparent = parent->GetParent();
+  if (!grandparent)
+    return false;
+
+  return grandparent->GetRole() == ui::AX_ROLE_IFRAME_PRESENTATIONAL;
+}
+
 std::string BrowserAccessibility::GetTextRecursive() const {
   if (!name_.empty()) {
     return name_;
   }
 
   std::string result;
   for (uint32 i = 0; i < PlatformChildCount(); ++i)
     result += PlatformGetChild(i)->GetTextRecursive();
   return result;
 }
 
 int BrowserAccessibility::GetStaticTextLenRecursive() const {
   if (GetRole() == ui::AX_ROLE_STATIC_TEXT)
     return static_cast<int>(GetStringAttribute(ui::AX_ATTR_VALUE).size());
 
   int len = 0;
   for (size_t i = 0; i < InternalChildCount(); ++i)
     len += InternalGetChild(i)->GetStaticTextLenRecursive();
   return len;
 }
 
 }  // namespace content