Add expected labels to errant tests in display-contents-role-and-labe…

…l.html (web-platform-tests#45856)

There are some tests in display-contents-role-and-label.html that have class
".ex-role-and-label" (indicating they should have their labels tested) but have
no "data-expectedlabel" attribute specifying the expected label. This
discrepancy causes spurious test failures. This commit fixes the problem by
adding "data-expectedlabel" attributes to the affected tests.

css/css-display/accessibility/display-contents-role-and-label.html

@@ -131,21 +131,21 @@ <h3 style="display: contents;" data-expectedrole="heading" data-expectedlabel="x
 
   <!-- Landmarks and regions -->
   <header style="display: contents;" data-expectedrole="banner" data-testname="header with display: contents has banner role" class="ex-role">x</header>
-  <nav style="display: contents;" aria-label="label" data-expectedrole="navigation" data-testname="nav with display: contents and aria-label has navigation role" class="ex-role-and-label">x</nav>
-  <aside style="display: contents;" aria-label="label" data-expectedrole="complementary" data-testname="aside with display: contents and aria-label has complementary role" class="ex-role-and-label">x</aside>
+  <nav style="display: contents;" aria-label="label" data-expectedrole="navigation" data-expectedlabel="label" data-testname="nav with display: contents and aria-label has navigation role" class="ex-role-and-label">x</nav>
+  <aside style="display: contents;" aria-label="label" data-expectedrole="complementary" data-expectedlabel="label" data-testname="aside with display: contents and aria-label has complementary role" class="ex-role-and-label">x</aside>
   <main style="display: contents;" data-expectedrole="main" data-testname="main with display: contents has main role" class="ex-role">x</main>
   <footer style="display: contents;" data-expectedrole="contentinfo" data-testname="footer with display: contents has contentinfo role" class="ex-role">x</footer>
   <form aria-label="label" style="display: contents;" data-expectedrole="form" data-expectedlabel="label" data-testname="form with display: contents has form role" class="ex-role-and-label">x</form>
   <search style="display: contents;" data-expectedrole="search" data-testname="search with display: contents has search role" class="ex-role">x</search>
   <section aria-label="label" style="display: contents;" data-expectedrole="region" data-expectedlabel="label" data-testname="section with aria-label and display: contents has region role" class="ex-role-and-label"></section>
 
   <div role="banner" style="display: contents;" data-expectedrole="banner" data-testname="div with role banner and display: contents has banner role" class="ex-role">x</div>
-  <div role="navigation" aria-label="label" style="display: contents;" data-expectedrole="navigation" data-testname="div with role navigation, aria-label and display: contents has navigation role" class="ex-role-and-label">x</div>
-  <div role="complementary" aria-label="label" style="display: contents;" data-expectedrole="complementary" data-testname="div with role complementary, aria-label and display: contents has complementary role" class="ex-role-and-label">x</div>
+  <div role="navigation" aria-label="label" style="display: contents;" data-expectedrole="navigation" data-expectedlabel="label" data-testname="div with role navigation, aria-label and display: contents has navigation role" class="ex-role-and-label">x</div>
+  <div role="complementary" aria-label="label" style="display: contents;" data-expectedrole="complementary" data-expectedlabel="label" data-testname="div with role complementary, aria-label and display: contents has complementary role" class="ex-role-and-label">x</div>
   <div role="main" style="display: contents;" data-expectedrole="main" data-testname="div with role main and display: contents has main role" class="ex-role">x</div>
   <div role="contentinfo" style="display: contents;" data-expectedrole="contentinfo" data-testname="div with role contentinfo and display: contents has contentinfo role" class="ex-role">x</div>
   <div role="form" aria-label="label" style="display: contents;" data-expectedrole="form" data-expectedlabel="label" data-testname="div with role form, aria-label and display: contents has form role" class="ex-role-and-label">x</div>
-  <div role="search" aria-label="label" style="display: contents;" data-expectedrole="search" data-testname="div with role search and display: contents has search role" class="ex-role-and-label">x</div>
+  <div role="search" aria-label="label" style="display: contents;" data-expectedrole="search" data-expectedlabel="label" data-testname="div with role search and display: contents has search role" class="ex-role-and-label">x</div>
   <div role="region" aria-label="label" style="display: contents;" data-expectedrole="region" data-expectedlabel="label" data-testname="div with role region, aria-label and display: contents has region role" class="ex-role-and-label">x</div>
 
   <!-- Links -->