Tests that modules and themes can alter variables in html.tpl.php.
function testThemeHtmlTplPhpAttributes() {
$this
->drupalGet('');
$attributes = $this
->xpath('/html[@theme_test_html_attribute="theme test html attribute value"]');
$this
->assertTrue(count($attributes) == 1, 'Attribute set in the html element via hook_preprocess_HOOK() for html.tpl.php found.');
$attributes = $this
->xpath('/html/body[@theme_test_body_attribute="theme test body attribute value"]');
$this
->assertTrue(count($attributes) == 1, 'Attribute set in the body element via hook_preprocess_HOOK() for html.tpl.php found.');
}