top-level-ize gn's pkg_config in audio/BUILD.gn

media/audio/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/linux/pkg_config.gni")
 import("//media/media_options.gni")
 
 # When libpulse is not directly linked, use stubs to allow for dlopening of the
 # binary.
 if (!link_pulseaudio) {
@@ skipping 196 matching lines @@
 
   if (use_cras) {
     sources += [
       "cras/audio_manager_cras.cc",
       "cras/audio_manager_cras.h",
       "cras/cras_input.cc",
       "cras/cras_input.h",
       "cras/cras_unified.cc",
       "cras/cras_unified.h",
     ]
-
-    pkg_config("libcras") {
-      packages = [ "libcras" ]
-    }
     configs += [ ":libcras" ]
     deps += [ "//chromeos:chromeos" ]
   }
 
   if (use_pulseaudio) {
     sources += [
       "pulse/audio_manager_pulse.cc",
       "pulse/audio_manager_pulse.h",
       "pulse/pulse_input.cc",
       "pulse/pulse_input.h",
       "pulse/pulse_output.cc",
       "pulse/pulse_output.h",
       "pulse/pulse_util.cc",
       "pulse/pulse_util.h",
     ]
 
     if (link_pulseaudio) {
-      pkg_config("libpulse") {
-        packages = [ "libpulse" ]
-      }
       configs += [ ":libpulse" ]
     } else {
       # TODO(ajwong): Technically, this dl should go in the action.
       libs += [ "dl" ]
       deps += [ ":pulse_generate_stubs" ]
       sources += get_target_outputs(":pulse_generate_stubs")
     }
   }
 
   configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 }
 
+if (use_cras) {
+  pkg_config("libcras") {
+    packages = [ "libcras" ]
+  }
+}
+
+if (use_pulseaudio) {
+  if (link_pulseaudio) {

[Dirk Pranke, 2015/11/21 02:43:14]

nit: this could be just use_pulseaudio && link_pulseaudio

+    pkg_config("libpulse") {
+      packages = [ "libpulse" ]
+    }
+  }
+}
+
 source_set("test_support") {
   testonly = true
   sources = [
     "audio_unittest_util.cc",
     "audio_unittest_util.h",
     "mock_audio_manager.cc",
     "mock_audio_manager.h",
     "mock_audio_source_callback.cc",
     "mock_audio_source_callback.h",
     "test_audio_input_controller_factory.cc",
@@ skipping 78 matching lines @@
     ]
   }
 
   if (use_alsa) {
     sources += [
       "alsa/alsa_output_unittest.cc",
       "audio_low_latency_input_output_unittest.cc",
     ]
   }
 }