[cast_channel] Make cast_channel related files not depend on "cast_channel.h"

extensions/browser/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/config/features.gni")
 import("//extensions/features/features.gni")
 
 assert(enable_extensions)
 
 group("browser") {
@@ skipping 234 matching lines @@
     "warning_service_factory.h",
     "warning_set.cc",
     "warning_set.h",
     "web_ui_user_script_loader.cc",
     "web_ui_user_script_loader.h",
   ]
 
   deps = [
     "//base:i18n",
     "//components/cast_certificate",
+    "//components/cast_channel",
     "//components/crx_file",
     "//components/guest_view/browser",
     "//components/keyed_service/content",
     "//components/keyed_service/core",
     "//components/pref_registry",
     "//components/prefs",
     "//components/sessions",
     "//components/sync",
     "//components/update_client",
     "//components/update_client",
@@ skipping 124 matching lines @@
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
     "api/alarms/alarms_api_unittest.cc",
     "api/api_resource_manager_unittest.cc",
     "api/bluetooth/bluetooth_event_router_unittest.cc",
     "api/cast_channel/cast_auth_util_unittest.cc",
     "api/cast_channel/cast_channel_api_unittest.cc",
+    "api/cast_channel/cast_channel_enum_util_unittest.cc",
     "api/cast_channel/cast_framer_unittest.cc",
     "api/cast_channel/cast_socket_service_unittest.cc",
     "api/cast_channel/cast_socket_unittest.cc",
     "api/cast_channel/cast_transport_unittest.cc",
     "api/cast_channel/keep_alive_delegate_unittest.cc",
     "api/cast_channel/logger_unittest.cc",
     "api/declarative/declarative_rule_unittest.cc",
     "api/declarative/deduping_factory_unittest.cc",
     "api/declarative/rules_registry_unittest.cc",
     "api/declarative_webrequest/webrequest_condition_attribute_unittest.cc",
@@ skipping 105 matching lines @@
       "api/media_perception_private/media_perception_api_manager_unittest.cc",
       "api/webcam_private/visca_webcam_unittest.cc",
     ]
 
     deps += [
       "//chromeos:media_perception_proto",
       "//chromeos:test_support",
     ]
   }
 }