Add grid/flex layout support for <fieldset>

content/browser/accessibility/accessibility_win_browsertest.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 <stddef.h>
 #include <stdint.h>
 
 #include <memory>
 #include <vector>
 
@@ skipping 956 matching lines @@
   EXPECT_EQ(L"input", std::wstring(node_name, node_name.Length()));
   EXPECT_EQ(NODETYPE_ELEMENT, node_type);
   EXPECT_EQ(0u, num_children);
 }
 
 IN_PROC_BROWSER_TEST_F(AccessibilityWinBrowserTest, TestRoleGroup) {
   LoadInitialAccessibilityTreeFromHtml(
       "<fieldset></fieldset><div role=group></div>");
 
   // Check the browser's copy of the renderer accessibility tree.
-  AccessibleChecker grouping1_checker(std::wstring(), ROLE_SYSTEM_GROUPING,
+  AccessibleChecker grouping1_checker(std::wstring(), ROLE_SYSTEM_CLIENT,

[aboxhall, 2016/07/27 17:21:50]

I'm guessing this is a result of the "anonymous inner block" being added.
Ideally, the results of these tests shouldn't change at all, just like the pixel
tests haven't changed - this is going to affect the user experience for
assistive technology users. We may need to explore if some extra work needs to
be done in modules/accessibility in Blink.

                                       std::wstring());
   AccessibleChecker grouping2_checker(std::wstring(), ROLE_SYSTEM_GROUPING,
                                       std::wstring());
   AccessibleChecker document_checker(std::wstring(), ROLE_SYSTEM_DOCUMENT,
                                      std::wstring());
   document_checker.AppendExpectedChild(&grouping1_checker);
   document_checker.AppendExpectedChild(&grouping2_checker);
   document_checker.CheckAccessible(GetRendererAccessible());
 }
 
@@ skipping 771 matching lines @@
   ASSERT_EQ(nullptr, manager->GetParentHWND());
 
   // Now add the RWHVA's window to the root window and ensure that we have
   // an HWND for accessibility now.
   web_contents_view->GetNativeView()->AddChild(
       web_contents->GetRenderWidgetHostView()->GetNativeView());
   ASSERT_NE(nullptr, manager->GetParentHWND());
 }
 
 }  // namespace content