Revert "[video-raf] Enable video-raf by default"

This reverts commit bbe1b84e.

Reason for revert: We no longer have 3 API OWNER LGTMS

Original change's description:
> [video-raf] Enable video-raf by default
> 
> This CL turns on HTMLVideoElement.requestAnimationFrame() by default.
> 
> Spec: https://wicg.github.io/video-raf/
> Blink-dev intent-to-ship: https://wicg.github.io/video-raf/
> WPT: https://wpt.fyi/results/video-raf
> 
> Bug: 1012063
> Change-Id: I5f44a430078e8272d2f9ebb1482e11e936697fb5
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2101242
> Commit-Queue: Thomas Guilbert <tguilbert@chromium.org>
> Commit-Queue: Chris Harrelson <chrishtr@chromium.org>
> Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
> Reviewed-by: Kenneth Russell <kbr@chromium.org>
> Auto-Submit: Thomas Guilbert <tguilbert@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#749965}

TBR=kbr@chromium.org,chrishtr@chromium.org,tguilbert@chromium.org

Change-Id: I0af2785d83863dea9943a491c3679874de0b8cb8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1012063
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2103391Reviewed-by: Thomas Guilbert <tguilbert@chromium.org>
Commit-Queue: Thomas Guilbert <tguilbert@chromium.org>
Cr-Commit-Position: refs/heads/master@{#750291}

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -1755,7 +1755,7 @@
     {
       // See https://crbug.com/1012063
       name: "VideoRequestAnimationFrame",
-      status: "stable",
+      status: "experimental",
     },
     {
       name: "VideoRotateToFullscreen",

third_party/blink/web_tests/virtual/stable/webexposed/element-instance-property-listing-expected.txt

@@ -1100,7 +1100,6 @@ html element video
     property autoplay
     property buffered
     property canPlayType
-    property cancelAnimationFrame
     property captureStream
     property controls
     property controlsList
@@ -1135,7 +1134,6 @@ html element video
     property preload
     property readyState
     property remote
-    property requestAnimationFrame
     property requestPictureInPicture
     property seekable
     property seeking

third_party/blink/web_tests/virtual/stable/webexposed/global-interface-listing-expected.txt

@@ -3685,10 +3685,8 @@ interface HTMLVideoElement : HTMLMediaElement
     getter webkitDroppedFrameCount
     getter webkitSupportsFullscreen
     getter width
-    method cancelAnimationFrame
     method constructor
     method getVideoPlaybackQuality
-    method requestAnimationFrame
     method requestPictureInPicture
     method webkitEnterFullScreen
     method webkitEnterFullscreen