[Cast] Consolidate plethora of GYP files into cast.gyp and cast_testing.gypi.

media/cast/cast_receiver.gyp

-# Copyright 2013 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.
-
-{
-  'variables': {
-    'chromium_code': 1,
-  },
-  'includes': [
-     'audio_receiver/audio_receiver.gypi',
-     'video_receiver/video_receiver.gypi',
-  ],
-  'targets': [
-    {
-      'target_name': 'cast_receiver',
-      'type': 'static_library',
-      'include_dirs': [
-        '<(DEPTH)/',
-        '<(DEPTH)/third_party/',
-        '<(DEPTH)/third_party/webrtc/',
-      ],
-      'sources': [
-        'cast_receiver.h',
-        'cast_receiver_impl.cc',
-        'cast_receiver_impl.h',
-      ], # source
-      'dependencies': [
-        '<(DEPTH)/media/cast/transport/cast_transport.gyp:cast_transport',
-        'cast_audio_receiver',
-        'cast_video_receiver',
-        'rtp_receiver/rtp_receiver.gyp:cast_rtp_receiver',
-      ],
-    },
-  ],
-}