Add yet more GN isolates ...

printing/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("//build/config/ui.gni")
 import("//testing/test.gni")
 if (is_mac) {
   import("//build/config/mac/mac_sdk.gni")
 }
@@ skipping 169 matching lines @@
   if (is_android) {
     sources += [
       "printing_context_android.cc",
       "printing_context_android.h",
     ]
 
     deps += [ ":printing_jni_headers" ]
   }
 }
 
+# TODO(GYP): Delete this after we've converted everything to GN.
+# The _run targets exist only for compatibility w/ GYP.
+group("printing_unittests_run") {
+  testonly = true
+  deps = [
+    ":printing_unittests",
+  ]
+}
+
 test("printing_unittests") {
   sources = [
     "emf_win_unittest.cc",
     "page_number_unittest.cc",
     "page_range_unittest.cc",
     "page_setup_unittest.cc",
     "pdf_metafile_cg_mac_unittest.cc",
     "printed_page_unittest.cc",
     "printing_context_win_unittest.cc",
     "printing_test.h",
@@ skipping 43 matching lines @@
   }
 
   # GYP: //printing/printing.gyp:printing_java
   android_library("printing_java") {
     deps = [
       "//base:base_java",
     ]
     DEPRECATED_java_in_dir = "android/java/src"
   }
 }