Implement Linux IME support

services/keyboard/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/android/rules.gni")
+if (is_android) {
+  import("//build/config/android/config.gni")
+  import("//build/config/android/rules.gni")
 
-android_library("keyboard") {
-  java_files = [
-    "src/org/chromium/mojo/keyboard/InputConnectionAdaptor.java",
-    "src/org/chromium/mojo/keyboard/KeyboardServiceImpl.java",
-    "src/org/chromium/mojo/keyboard/KeyboardServiceState.java",
-  ]
+  android_library("keyboard") {
+    java_files = [
+      "src/org/chromium/mojo/keyboard/InputConnectionAdaptor.java",
+      "src/org/chromium/mojo/keyboard/KeyboardServiceImpl.java",
+      "src/org/chromium/mojo/keyboard/KeyboardServiceState.java",
+    ]
 
-  deps = [
-    "//mojo/public/java:bindings",
-    "//mojo/public/java:system",
-    "//mojo/services/keyboard/interfaces:interfaces_java",
-  ]
+    deps = [
+      "//mojo/public/java:bindings",
+      "//mojo/public/java:system",
+      "//mojo/services/keyboard/interfaces:interfaces_java",
+    ]
+  }
 }
+
+if (is_linux) {
+  import("//mojo/public/mojo_application.gni")
+
+  mojo_native_application("keyboard") {
+    sources = [
+      "linux/keyboard_service_impl.cc",
+      "linux/main.cc",
+    ]
+
+    deps = [
+      "//base",
+      "//mojo/application",
+      "//mojo/public/cpp/application",
+      "//mojo/public/cpp/bindings:callback",
+      "//mojo/public/cpp/system",
+      "//mojo/services/keyboard/interfaces",
+      "//mojo/services/native_viewport/interfaces",
+      "//mojo/services/native_viewport/cpp:args",
+    ]
+  }
+}