Retire PreloadDefaultIsMetadata runtime enabled flag.

Feature was enabled by default in M64. Flag isn't required anymore.

Bug: 310450
Change-Id: I5e6bd409ad9fc874cd2e9401e10707be9af1e6a8
Reviewed-on: https://chromium-review.googlesource.com/c/1324136Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606508}

third_party/blink/public/platform/web_runtime_features.h

@@ -142,7 +142,6 @@ class WebRuntimeFeatures {
   BLINK_PLATFORM_EXPORT static void EnablePictureInPictureAPI(bool);
   BLINK_PLATFORM_EXPORT static void EnablePortals(bool);
   BLINK_PLATFORM_EXPORT static void EnablePreciseMemoryInfo(bool);
-  BLINK_PLATFORM_EXPORT static void EnablePreloadDefaultIsMetadata(bool);
   BLINK_PLATFORM_EXPORT static void EnablePreloadImageSrcSetEnabled(bool);
   BLINK_PLATFORM_EXPORT static void EnablePrintBrowser(bool);
   BLINK_PLATFORM_EXPORT static void EnablePresentationAPI(bool);

third_party/blink/renderer/core/html/media/html_media_element.cc

@@ -2375,9 +2375,7 @@ WebMediaPlayer::Preload HTMLMediaElement::PreloadType() const {
   // The spec does not define an invalid value default:
   // https://www.w3.org/Bugs/Public/show_bug.cgi?id=28950
   UseCounter::Count(GetDocument(), WebFeature::kHTMLMediaElementPreloadDefault);
-  return RuntimeEnabledFeatures::PreloadDefaultIsMetadataEnabled()
-             ? WebMediaPlayer::kPreloadMetaData
-             : WebMediaPlayer::kPreloadAuto;
+  return WebMediaPlayer::kPreloadMetaData;
 }
 
 String HTMLMediaElement::EffectivePreload() const {

third_party/blink/renderer/platform/exported/web_runtime_features.cc

@@ -328,10 +328,6 @@ void WebRuntimeFeatures::EnablePortals(bool enable) {
   RuntimeEnabledFeatures::SetPortalsEnabled(enable);
 }
 
-void WebRuntimeFeatures::EnablePreloadDefaultIsMetadata(bool enable) {
-  RuntimeEnabledFeatures::SetPreloadDefaultIsMetadataEnabled(enable);
-}
-
 void WebRuntimeFeatures::EnablePreloadImageSrcSetEnabled(bool enable) {
   RuntimeEnabledFeatures::SetPreloadImageSrcSetEnabled(enable);
 }

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -997,10 +997,6 @@
       name: "PrefixedVideoFullscreen",
       status: "stable",
     },
-    {
-      name: "PreloadDefaultIsMetadata",
-      status: "stable",
-    },
     {
       name: "PreloadImageSrcSet",
       status: "experimental",