GN: Get //chrome/* mostly working on android

components/gcm_driver/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.
 
+# GYP version: components/gcm_driver.gypi:gcm_driver
 static_library("gcm_driver") {
   sources = [
     "android/component_jni_registrar.cc",
     "android/component_jni_registrar.h",
     "default_gcm_app_handler.cc",
     "default_gcm_app_handler.h",
     "gcm_activity.cc",
     "gcm_activity.h",
     "gcm_app_handler.cc",
     "gcm_app_handler.h",
@@ skipping 78 matching lines @@
     sources -= [
       "fake_gcm_client.cc",
       "fake_gcm_client.h",
       "fake_gcm_client_factory.cc",
       "fake_gcm_client_factory.h",
     ]
     deps -= [ "//google_apis/gcm" ]
   }
 }
 
-#TODO(GYP) gcm_driver_java gcm_driver_jni_headers
+if (is_android) {
+  import("//build/config/android/rules.gni")
+
+  # GYP version: components/gcm_driver.gypi:gcm_driver_jni_headers
+  generate_jni("jni_headers") {
+    sources = [
+      "android/java/src/org/chromium/components/gcm_driver/GCMDriver.java",
+    ]
+    jni_package = "components/gcm_driver"
+  }
+}