Convert test_support source sets to static libs

components/drive/BUILD.gn

 # Copyright (c) 2015 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("//third_party/protobuf/proto_library.gni")
 
-source_set("drive") {
+static_library("drive") {
   sources = [
     "drive_api_util.cc",
     "drive_api_util.h",
     "drive_app_registry.cc",
     "drive_app_registry.h",
     "drive_app_registry_observer.h",
     "drive_notification_manager.cc",
     "drive_notification_manager.h",
     "drive_notification_observer.h",
     "drive_pref_names.cc",
@@ skipping 119 matching lines @@
     ":proto",
   ]
 }
 
 proto_library("proto") {
   sources = [
     "drive.proto",
   ]
 }
 
-source_set("test_support") {
+static_library("test_support") {
   testonly = true
   sources = [
     "service/dummy_drive_service.cc",
     "service/dummy_drive_service.h",
     "service/fake_drive_service.cc",
     "service/fake_drive_service.h",
     "service/test_util.cc",
     "service/test_util.h",
   ]
   deps = [
     ":drive",
     ":proto",
     "//base",
     "//components/prefs:test_support",
     "//content/test:test_support",
     "//google_apis:test_support",
     "//net:net",
   ]
 }
 
-source_set("test_support_chromeos") {
-  testonly = true
-  sources = [
-    "chromeos/drive_test_util.cc",
-    "chromeos/drive_test_util.h",
-    "chromeos/dummy_file_system.cc",
-    "chromeos/dummy_file_system.h",
-    "chromeos/fake_file_system.cc",
-    "chromeos/fake_file_system.h",
-    "chromeos/fake_free_disk_space_getter.cc",
-    "chromeos/fake_free_disk_space_getter.h",
-  ]
-  deps = [
-    ":drive",
-    ":drive_chromeos",
-    ":proto",
-    "//base",
-    "//components/prefs:test_support",
-    "//content/test:test_support",
-    "//google_apis:test_support",
-  ]
+if (is_chromeos) {
+  static_library("test_support_chromeos") {
+    testonly = true
+    sources = [
+      "chromeos/drive_test_util.cc",
+      "chromeos/drive_test_util.h",
+      "chromeos/dummy_file_system.cc",
+      "chromeos/dummy_file_system.h",
+      "chromeos/fake_file_system.cc",
+      "chromeos/fake_file_system.h",
+      "chromeos/fake_free_disk_space_getter.cc",
+      "chromeos/fake_free_disk_space_getter.h",
+    ]
+    deps = [
+      ":drive",
+      ":drive_chromeos",
+      ":proto",
+      "//base",
+      "//components/prefs:test_support",
+      "//content/test:test_support",
+      "//google_apis:test_support",
+    ]
+  }
 }