Remove border and padding from iframes in fullscreen

Source/core/css/fullscreen.css

Index: Source/core/css/fullscreen.css
diff --git a/Source/core/css/fullscreen.css b/Source/core/css/fullscreen.css
index fb79d5894d43d3ae2ed516dc10546adf68dca7bc..60a0aa02f80298e0aee5377f4f16e98e3cc9712f 100644
--- a/Source/core/css/fullscreen.css
+++ b/Source/core/css/fullscreen.css
@@ -30,6 +30,16 @@ iframe:-webkit-full-screen {
 
 /* 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;
+}
+
 /* FIXME: Remove these rules when moving Fullscreen to top layer.
    (see crbug.com/240576) */
 :-webkit-full-screen {