Enable more tests in GN build.

components/cdm/renderer/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.
+
+static_library("renderer") {
+  sources = [
+    "widevine_key_systems.cc",
+    "widevine_key_systems.h",
+  ]
+
+  if (is_android) {
+    sources += [
+      "android_key_systems.cc",
+      "android_key_systems.h",
+    ]
+  }
+
+  deps = [
+    "//base",
+    "//components/cdm/common",
+    "//content/public/common",
+    "//content/public/renderer",
+    "//third_party/widevine/cdm:version_h",
+  ]
+}