Revert of [cast_channel] Move cast_channel related files from //extensions to //components

components/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/chrome_build.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//printing/features/features.gni")
 import("//rlz/features/features.gni")
 import("//testing/test.gni")
@@ skipping 154 matching lines @@
       "//components/image_fetcher/ios:unit_tests",
       "//components/signin/ios/browser:unit_tests",
       "//components/translate/ios/browser:unit_tests",
     ]
   } else {  # !iOS
     deps += [
       "//components/autofill/content/browser:unit_tests",
       "//components/autofill/content/common:unit_tests",
       "//components/autofill/content/renderer:unit_tests",
       "//components/cast_certificate:unit_tests",
-      "//components/cast_channel:unit_tests",
       "//components/certificate_reporting:unit_tests",
       "//components/certificate_transparency:unit_tests",
       "//components/contextual_search:unit_tests",
       "//components/crash/content/app:unit_tests",
       "//components/crash/core/common:unit_tests",
       "//components/data_reduction_proxy/content/browser:unit_tests",
       "//components/data_reduction_proxy/core/browser:unit_tests",
       "//components/data_reduction_proxy/core/common:unit_tests",
       "//components/data_use_measurement/core:unit_tests",
       "//components/discardable_memory/common:unit_tests",
@@ skipping 324 matching lines @@
       "//testing/perf",
       "//url",
     ]
 
     if (!is_ios) {
       sources += [ "discardable_memory/common/discardable_shared_memory_heap_perftest.cc" ]
       deps += [ "//components/discardable_memory/common" ]
     }
   }
 }