Remove ModulePreload runtime enabled flag.

The feature shipped in M66.

BUG=740886

Change-Id: I8a0c0927e80100ba652018c4d476e8797ad0349a
Reviewed-on: https://chromium-review.googlesource.com/c/1323895
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Reviewed-by: Kunihiko Sakamoto <ksakamoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606317}

third_party/blink/renderer/core/html/link_rel_attribute.cc

@@ -94,8 +94,7 @@ LinkRelAttribute::LinkRelAttribute(const String& rel) : LinkRelAttribute() {
     } else if (DeprecatedEqualIgnoringCase(link_type, "manifest")) {
       is_manifest_ = true;
     } else if (DeprecatedEqualIgnoringCase(link_type, "modulepreload")) {
-      if (RuntimeEnabledFeatures::ModulePreloadEnabled())
-        is_module_preload_ = true;
+      is_module_preload_ = true;
     } else if (DeprecatedEqualIgnoringCase(link_type, "serviceworker")) {
       is_service_worker_ = true;
     } else if (DeprecatedEqualIgnoringCase(link_type, "canonical")) {

third_party/blink/renderer/core/html/rel_list.cc

@@ -43,8 +43,7 @@ bool RelList::ValidateTokenValue(const AtomicString& token_value,
   //  https://html.spec.whatwg.org/multipage/links.html#linkTypes
   if (GetElement().HasTagName(html_names::kLinkTag)) {
     if (SupportedTokensLink().Contains(token_value) ||
-        (RuntimeEnabledFeatures::ModulePreloadEnabled() &&
-         token_value == "modulepreload")) {
+        token_value == "modulepreload") {
       return true;
     }
   } else if ((GetElement().HasTagName(html_names::kATag) ||

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -768,10 +768,6 @@
       name: "ModuleDedicatedWorker",
       status: "experimental",
     },
-    {
-      name: "ModulePreload",
-      status: "stable",
-    },
     {
       name: "ModuleServiceWorker",
       status: "test",