Avoid enabling accessibility for WebContents that are never shown

content/browser/accessibility/accessibility_ui.cc

 // Copyright (c) 2013 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/accessibility_ui.h"
 
 #include <memory>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/json/json_writer.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "content/browser/accessibility/accessibility_tree_formatter.h"
 #include "content/browser/accessibility/accessibility_tree_formatter_blink.h"
 #include "content/browser/accessibility/browser_accessibility_manager.h"
 #include "content/browser/accessibility/browser_accessibility_state_impl.h"
+#include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_view_base.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/browser/webui/web_ui_data_source_impl.h"
 #include "content/common/view_message_enums.h"
 #include "content/grit/content_resources.h"
 #include "content/public/browser/favicon_status.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
@@ skipping 80 matching lines @@
   std::unique_ptr<RenderWidgetHostIterator> widgets(
       RenderWidgetHost::GetRenderWidgetHosts());
 
   while (RenderWidgetHost* widget = widgets->GetNextHost()) {
     // Ignore processes that don't have a connection, such as crashed tabs.
     if (!widget->GetProcess()->HasConnection())
       continue;
     RenderViewHost* rvh = RenderViewHost::From(widget);
     if (!rvh)
       continue;
+    // Ignore views that are never visible, like background pages.
+    if (static_cast<RenderViewHostImpl*>(rvh)->GetDelegate()->IsNeverVisible())
+      continue;
     BrowserContext* context = rvh->GetProcess()->GetBrowserContext();
     if (context != current_context)
       continue;
 
     rvh_list->Append(BuildTargetDescriptor(rvh));
   }
 
   base::DictionaryValue data;
   data.Set("list", rvh_list.release());
   data.SetInteger(
@@ skipping 131 matching lines @@
       web_contents->GetRootBrowserAccessibilityManager()->GetRoot(),
       &accessibility_contents_utf16);
   result->Set("tree",
               new base::StringValue(
                   base::UTF16ToUTF8(accessibility_contents_utf16)));
   web_ui()->CallJavascriptFunctionUnsafe("accessibility.showTree",
                                          *(result.get()));
 }
 
 }  // namespace content