media: Fix gn deps on media/ targets.

media/cdm/ppapi/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("//chrome/version.gni")  # TODO layering violation!
 import("//media/cdm/ppapi/ppapi_cdm_adapter.gni")
 import("//media/media_options.gni")
 
 # The GYP version supports build flags "use_fake_video_decoder" and
@@ skipping 47 matching lines @@
   output = "$target_gen_dir/clearkeycdmadapter_version.rc"
 }
 
 ppapi_cdm_adapter("clearkeycdmadapter") {
   # Check whether the plugin's origin URL is valid.
   defines = [ "CHECK_DOCUMENT_URL" ]
   deps = [
     ":clearkeycdm",
     ":clearkeycdmadapter_resources",
     "//base",  # Required for the allocator implementation.
-    "//ppapi/cpp",
   ]
 }