[RemotePlayback] Keep track of source compatibility and reject prompt() correspondingly

third_party/WebKit/public/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/buildflag_header.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//third_party/WebKit/public/public_features.gni")
 import("//third_party/WebKit/Source/config.gni")
 import("//third_party/WebKit/Source/core/core.gni")
 import("//tools/grit/grit_rule.gni")
@@ skipping 62 matching lines @@
   header = "public_features.h"
   flags = [ "DEBUG_DEVTOOLS=$debug_devtools" ]
 }
 
 if (is_android) {
   java_cpp_enum("blink_headers_java_enums_srcjar") {
     sources = [
       "./platform/WebDisplayMode.h",
       "./platform/WebInputEvent.h",
       "./platform/WebTextInputType.h",
+      "./platform/modules/remoteplayback/WebRemotePlaybackAvailability.h",
     ]
   }
 
   android_library("blink_headers_java") {
     deps = [
       "//third_party/android_tools:android_support_annotations_java",
     ]
     srcjar_deps = [ ":blink_headers_java_enums_srcjar" ]
   }
 }
@@ skipping 267 matching lines @@
     "platform/modules/permissions/WebPermissionType.h",
     "platform/modules/presentation/WebPresentationClient.h",
     "platform/modules/presentation/WebPresentationController.h",
     "platform/modules/presentation/WebPresentationError.h",
     "platform/modules/push_messaging/WebPushClient.h",
     "platform/modules/push_messaging/WebPushError.h",
     "platform/modules/push_messaging/WebPushPermissionStatus.h",
     "platform/modules/push_messaging/WebPushProvider.h",
     "platform/modules/push_messaging/WebPushSubscription.h",
     "platform/modules/push_messaging/WebPushSubscriptionOptions.h",
+    "platform/modules/remoteplayback/WebRemotePlaybackAvailability.h",
     "platform/modules/remoteplayback/WebRemotePlaybackClient.h",
     "platform/modules/remoteplayback/WebRemotePlaybackState.h",
     "platform/modules/screen_orientation/WebLockOrientationCallback.h",
     "platform/modules/screen_orientation/WebLockOrientationError.h",
     "platform/modules/screen_orientation/WebScreenOrientationClient.h",
     "platform/modules/screen_orientation/WebScreenOrientationLockType.h",
     "platform/modules/screen_orientation/WebScreenOrientationType.h",
     "platform/modules/serviceworker/WebNavigationPreloadState.h",
     "platform/modules/serviceworker/WebServiceWorker.h",
     "platform/modules/serviceworker/WebServiceWorkerCache.h",
@@ skipping 376 matching lines @@
 # relegated to a separate target to avoid duplication between the variants.
 source_set("shared_typemap_traits") {
   visibility = [ ":*" ]
   sources = [
     "web/WindowFeaturesStructTraits.cpp",
   ]
   deps = [
     ":new_wrapper_types_mojo_bindings_shared__generator",
   ]
 }