Add a requestFullscreen variant with a default (prefixed) type

third_party/WebKit/Source/core/html/shadow/MediaControls.cpp

Index: third_party/WebKit/Source/core/html/shadow/MediaControls.cpp
diff --git a/third_party/WebKit/Source/core/html/shadow/MediaControls.cpp b/third_party/WebKit/Source/core/html/shadow/MediaControls.cpp
index 81c0e66bbdf1b9b6aab0ebf05adf61937167a0fb..c7685babd45c0dc954c0a852c454b8367de70065 100644
--- a/third_party/WebKit/Source/core/html/shadow/MediaControls.cpp
+++ b/third_party/WebKit/Source/core/html/shadow/MediaControls.cpp
@@ -530,9 +530,7 @@ void MediaControls::showOverlayCastButtonIfNeeded() {
 }
 
 void MediaControls::enterFullscreen() {
-  // TODO(foolip): switch to Fullscreen::UnprefixedRequest when the unprefixed
-  // Fullscreen API has launched.
-  Fullscreen::requestFullscreen(mediaElement(), Fullscreen::PrefixedRequest);
+  Fullscreen::requestFullscreen(mediaElement());
 }
 
 void MediaControls::exitFullscreen() {