Add unit tests target to GN build.

chrome/browser/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/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//components/nacl/nacl_defines.gni")
 
 # //build/config/android/rules.gni imports //tools/grit/grit_rule.gni, which
@@ skipping 10 matching lines @@
 about_credits_file = "$target_gen_dir/about_credits.html"
 additional_modules_list_file =
     "$root_gen_dir/chrome/browser/internal/additional_modules_list.txt"
 
 gypi_values = exec_script("//build/gypi_to_gn.py",
                           [ rebase_path("../chrome_browser.gypi") ],
                           "scope",
                           [ "../chrome_browser.gypi" ])
 
 if (is_desktop_linux) {
+  # Gnome-keyring is normally dynamically loaded. The gnome_keyring config
+  # will set this up.
   pkg_config("gnome_keyring") {
     packages = [ "gnome-keyring-1" ]
+    defines = [
+      "USE_GNOME_KEYRING",
+      "DLOPEN_GNOME_KEYRING",
+    ]
+    ignore_libs = true
+  }
+
+  # If you want to link gnome-keyring directly (use only for unit tests)
+  # ADDITIONALLY add this config on top of ":gnome_keyring". pkg-config is a
+  # bit slow, so prefer not to run it again. In practice, gnome-keyring's libs
+  # are just itself and common gnome ones we link already, so we can get away
+  # with additionally just coding the library name here.
+  config("gnome_keyring_direct") {
+    libs = [ "gnome-keyring" ]
   }
 }
 
 static_library("browser") {
   configs += [
     "//build/config/compiler:wexit_time_destructors",
     "//third_party/WebKit/public:debug_devtools",
   ]
   defines = []
   sources = []
@@ skipping 1044 matching lines @@
     ]
   }
 
   if (enable_wifi_bootstrapping) {
     sources += [
       "local_discovery/wifi/mock_wifi_manager.cc",
       "local_discovery/wifi/mock_wifi_manager.h",
     ]
   }
 }