Remove the webkitallowfullscreen content attribute

Intent to Deprecate and Remove:
https://groups.google.com/a/chromium.org/d/msg/blink-dev/LupOLlogL-g/H8GsBEDGQeMJ

Tests were updated to use allowfullscreen instead of
webkitallowfullscreen, with a few exceptions:

fullscreen/full-screen-enabled-prefixed.html would have become redundant
with fullscreen/full-screen-enabled.html and was removed.

fullscreen/full-screen-iframe-with-mixed-allow-webkitallow-attribute.html
became a test for nested iframes with allowfullscreen and was renamed.

Finally, doctypes were added and whitespace cleaned up in touched test.

fullscreen/resources/full-screen-iframe-allowed-nested2.html depended on
being in quirks mode, since the size of the body element is smaller in
standards mode. Put the click event handler on window instead.

BUG=390008

Review URL: https://codereview.chromium.org/336313015

git-svn-id: svn://svn.chromium.org/blink/trunk@177332 bbb929c8-8fbe-4397-9dbb-9b2b20218538
diff --git a/third_party/WebKit/LayoutTests/fullscreen/exit-full-screen-iframe.html b/third_party/WebKit/LayoutTests/fullscreen/exit-full-screen-iframe.html
index 80d66ca4..e753659 100644
--- a/third_party/WebKit/LayoutTests/fullscreen/exit-full-screen-iframe.html
+++ b/third_party/WebKit/LayoutTests/fullscreen/exit-full-screen-iframe.html
@@ -1,3 +1,4 @@
+<!DOCTYPE html>
 <p>Test for <a href="http://bugs.webkit.org/show_bug.cgi?id=90327">bug 90327</a>: 
 webkitCancelFullScreen for iframes</p>
 <p>To test manually, click the "Go full screen" button - the page should enter full screen mode and immediately exit again, without crashing.</p>
@@ -21,5 +22,5 @@
     });
 }
 </script>
-<iframe id="frame" src="resources/inner.html" width="300" height="100" onload="runTest()" webkitallowfullscreen>
+<iframe id="frame" src="resources/inner.html" width="300" height="100" onload="runTest()" allowfullscreen>
 </iframe>