Initial native keyboard proof of concept.

services/keyboard_native/BUILD.gn

Index: services/keyboard_native/BUILD.gn
diff --git a/examples/echo_terminal/BUILD.gn b/services/keyboard_native/BUILD.gn
similarity index 53%
copy from examples/echo_terminal/BUILD.gn
copy to services/keyboard_native/BUILD.gn
index 0da27dd87b75ebec5bc4bd577e424a665133160a..c827642f6bf38c7eb60bc2096c4b9cf457853ab5 100644
--- a/examples/echo_terminal/BUILD.gn
+++ b/services/keyboard_native/BUILD.gn
@@ -4,17 +4,17 @@
 
 import("//mojo/public/mojo_application.gni")
 
-mojo_native_application("echo_terminal") {
-  deps = [
-    "//base",
-    "//mojo/application",
-    "//mojo/common",
-    "//mojo/public/cpp/application",
-    "//mojo/public/cpp/system",
-    "//mojo/services/terminal/public/interfaces",
-  ]
-
+mojo_native_application("keyboard_native") {
   sources = [
+    "keyboard_service_impl.cc",
+    "keyboard_service_impl.h",
     "main.cc",
   ]
+
+  deps = [
+    "//base",
+    "//mojo/public/cpp/application:standalone",
+    "//mojo/public/cpp/bindings",
+    "//mojo/services/keyboard/public/interfaces",
+  ]
 }