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

tools/ipc_fuzzer/replay/replay.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,
   },
   'targets': [
     {
       'target_name': 'ipc_fuzzer_replay',
       'type': 'executable',
       'dependencies': [
         '../message_lib/message_lib.gyp:ipc_message_lib',
         '../../../base/base.gyp:base',
         '../../../chrome/chrome.gyp:common',
         '../../../ipc/ipc.gyp:ipc',
-        '../../../media/cast/transport/cast_transport.gyp:cast_transport',
+        '../../../media/cast/cast.gyp:cast_transport',
       ],
       'sources': [
         'replay.cc',
         'replay_process.cc',
         'replay_process.h',
       ],
       'include_dirs': [
         '../../..',
       ],
       'defines': [
         'USE_CUPS',
       ],
     },
   ],
 }