GN Windows component build fixes

media/midi/BUILD.gn

 # Copyright 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("//build/config/android/config.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//media/media_options.gni")
 import("//testing/test.gni")
 
 if (is_android) {
   # For generate_jni().
   import("//build/config/android/rules.gni")
 }
 
 # Common configuration for targets in the media/midi directory.
 config("midi_config") {
   if (use_alsa) {
     defines = [
       "USE_ALSA",
       "USE_UDEV",
     ]
   }
 
   visibility = [ ":*" ]
 }
 
 # USB MIDI specific source files that are used in Android port, and unit tests.
-source_set("usb_midi") {
-  sources = [
-    "midi_manager_usb.cc",
-    "midi_manager_usb.h",
-    "usb_midi_descriptor_parser.cc",
-    "usb_midi_descriptor_parser.h",
-    "usb_midi_device.h",
-    "usb_midi_input_stream.cc",
-    "usb_midi_input_stream.h",
-    "usb_midi_jack.h",
-    "usb_midi_output_stream.cc",
-    "usb_midi_output_stream.h",
-  ]
-
-  defines = [ "MEDIA_IMPLEMENTATION" ]
-  deps = [
-    "//base",
-  ]
-}
+# These can't easily be a source set because "midi" is a component and the
+# component export flags must always be the same.
+usb_midi_sources = [
+  "midi_manager_usb.cc",
+  "midi_manager_usb.h",
+  "usb_midi_descriptor_parser.cc",
+  "usb_midi_descriptor_parser.h",
+  "usb_midi_device.h",
+  "usb_midi_export.h",
+  "usb_midi_input_stream.cc",
+  "usb_midi_input_stream.h",
+  "usb_midi_jack.h",
+  "usb_midi_output_stream.cc",
+  "usb_midi_output_stream.h",
+]
 
 # Android specific Java source files that are used to generate jni header files.
 if (is_android) {
   android_library("midi_java") {
     deps = [
       "//base:base_java",
     ]
 
     DEPRECATED_java_in_dir = "java/src"
   }
 
   generate_jni("midi_jni_headers") {
     sources = [
       "java/src/org/chromium/media/midi/UsbMidiDeviceAndroid.java",
       "java/src/org/chromium/media/midi/UsbMidiDeviceFactoryAndroid.java",
     ]
     jni_package = "media/midi"
   }
 }
 
 component("midi") {
   sources = [
+    "midi_export.h",
     "midi_manager.cc",
     "midi_manager.h",
     "midi_manager_mac.cc",
     "midi_manager_mac.h",
     "midi_manager_win.cc",
     "midi_manager_win.h",
     "midi_message_queue.cc",
     "midi_message_queue.h",
     "midi_message_util.cc",
     "midi_message_util.h",
     "midi_port_info.cc",
     "midi_port_info.h",
     "midi_scheduler.cc",
     "midi_scheduler.h",
   ]
 
   configs += [ ":midi_config" ]
 
-  defines = [ "MEDIA_IMPLEMENTATION" ]
+  defines = [ "MIDI_IMPLEMENTATION" ]
   deps = []
   libs = []
 
   if (is_android) {
     sources += [
-      "midi_jni_registrar.cc",
-      "midi_jni_registrar.h",
-      "midi_manager_android.cc",
-      "usb_midi_device_android.cc",
-      "usb_midi_device_android.h",
-      "usb_midi_device_factory_android.cc",
-      "usb_midi_device_factory_android.h",
-    ]
+                 "midi_jni_registrar.cc",
+                 "midi_jni_registrar.h",
+                 "midi_manager_android.cc",
+                 "usb_midi_device_android.cc",
+                 "usb_midi_device_android.h",
+                 "usb_midi_device_factory_android.cc",
+                 "usb_midi_device_factory_android.h",
+               ] + usb_midi_sources
+
+    # Since the USB sources are part of the component.
+    defines += [ "EXPORT_USB_MIDI" ]
 
     deps += [
       "//base:i18n",
       ":midi_jni_headers",
-      ":usb_midi",
     ]
   }
 
   if (is_mac) {
     libs += [
       "CoreAudio.framework",
       "CoreMIDI.framework",
     ]
   }
 
@@ skipping 31 matching lines @@
 
   configs += [ ":midi_config" ]
   deps = [
     ":midi",
     "//base/test/:run_all_unittests",
     "//base/test/:test_support",
     "//testing/gtest",
   ]
 
   if (!is_android) {
-    deps += [ ":usb_midi" ]
+    sources += usb_midi_sources
   }
 
   if (is_mac) {
     sources += [ "midi_manager_mac_unittest.cc" ]
   }
 
   if (use_alsa && use_udev) {
     sources += [ "midi_manager_alsa_unittest.cc" ]
   }
 
   if (use_x11) {
     deps += [ "//tools/xdisplaycheck" ]
   }
 }