Move iframe border/padding to the standard Fullscreen UA style sheet

This spec bug was resolved very quickly: (Thanks, Anne!)
https://www.w3.org/Bugs/Public/show_bug.cgi?id=28332

The ua-style-iframe-border.html test is no longer needed, as it was
written specifically to handle the fact that the border rule was not
!important, which it now is.

BUG=402378

Review URL: https://codereview.chromium.org/1032253002

git-svn-id: svn://svn.chromium.org/blink/trunk@192610 bbb929c8-8fbe-4397-9dbb-9b2b20218538
diff --git a/third_party/WebKit/LayoutTests/fullscreen/rendering/ua-style-iframe-border.html b/third_party/WebKit/LayoutTests/fullscreen/rendering/ua-style-iframe-border.html
deleted file mode 100644
index 6ef676a..0000000
--- a/third_party/WebKit/LayoutTests/fullscreen/rendering/ua-style-iframe-border.html
+++ /dev/null
@@ -1,25 +0,0 @@
-<!DOCTYPE html>
-<title>Fullscreen UA style sheet removes iframe border</title>
-<script src="../../resources/testharness.js"></script>
-<script src="../../resources/testharnessreport.js"></script>
-<script src="../trusted-event.js"></script>
-<div id="log"></div>
-<iframe></iframe>
-<script>
-async_test(function()
-{
-    var iframe = document.querySelector("iframe");
-
-    // The HTML UA style sheet gives iframe a border.
-    // https://html.spec.whatwg.org/#embedded-content-rendering-rules
-    assert_equals(getComputedStyle(iframe).borderStyle, "inset");
-
-    document.addEventListener("fullscreenchange", this.step_func_done(function()
-    {
-        // The Fullscreen UA style sheet removes the iframe border.
-        assert_equals(getComputedStyle(iframe).borderStyle, "none");
-    }));
-
-    trusted_request(iframe);
-});
-</script>
diff --git a/third_party/WebKit/Source/core/css/fullscreen.css b/third_party/WebKit/Source/core/css/fullscreen.css
index 60a0aa02..9ed2424 100644
--- a/third_party/WebKit/Source/core/css/fullscreen.css
+++ b/third_party/WebKit/Source/core/css/fullscreen.css
@@ -25,21 +25,12 @@
 }
 
 iframe:-webkit-full-screen {
-    border: none;
-}
-
-/* Anything below are extensions over what the Fullscreen API mandates. */
-
-/* The border and padding of fullscreen iframes are removed, as there are sites
-   that set border or padding on iframes with the apparent expectation that they
-   will be ignored in fullscreen (see crbug.com/468292 and crbug.com/469133).
-   TODO(philipj): Remove this or merge into the above block when the spec bug
-   has been resolved: https://www.w3.org/Bugs/Public/show_bug.cgi?id=28332 */
-iframe:-webkit-full-screen {
     border: none !important;
     padding: 0 !important;
 }
 
+/* Anything below are extensions over what the Fullscreen API mandates. */
+
 /* FIXME: Remove these rules when moving Fullscreen to top layer.
    (see crbug.com/240576) */
 :-webkit-full-screen {