Add openvr_device.h and openvr_device_provider.h into BUILD.gn

device/vr/BUILD.gn

 # Copyright 2016 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("features.gni")
 import("//build/buildflag_header.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 
 if (is_android) {
   import("//build/config/android/rules.gni")  # For generate_jni().
@@ skipping 71 matching lines @@
       ]
       ldflags = [ "-landroid" ]
       libs = [ "//third_party/gvr-android-sdk/libgvr_shim_static_${current_cpu}.a" ]
       configs += [ "//third_party/gvr-android-sdk:libgvr_config" ]
     }
 
     if (enable_openvr) {
       deps += [ "//third_party/openvr:openvr" ]
       sources += [
         "openvr/openvr_device.cc",
+        "openvr/openvr_device.h",
         "openvr/openvr_device_provider.cc",
+        "openvr/openvr_device_provider.h",
       ]
     }
   }
 }
 
 if (enable_vr) {
   static_library("fakes") {
     testonly = true
 
     sources = [
@@ skipping 23 matching lines @@
 
   public_deps = [
     "//gpu/ipc/common:interfaces",
     "//mojo/common:common_custom_types",
   ]
 
   export_class_attribute = "DEVICE_VR_EXPORT"
   export_define = "DEVICE_VR_IMPLEMENTATION=1"
   export_header = "device/vr/vr_export.h"
 }