Remove Sync GetPose VRService call, implement VRVSyncProvider

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("//build/config/features.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 
 if (is_android) {
   import("//build/config/android/rules.gni")  # For generate_jni().
 }
 
-if (current_cpu == "arm" || current_cpu == "arm64") {
+if (enable_webvr) {
   component("vr") {
     output_name = "device_vr"
 
     sources = [
       "vr_device.cc",
       "vr_device.h",
       "vr_device_manager.cc",
       "vr_device_manager.h",
       "vr_device_provider.h",
       "vr_display_impl.cc",
       "vr_display_impl.h",
+      "vr_export.h",
       "vr_service_impl.cc",
       "vr_service_impl.h",
     ]
 
     deps = [
       ":mojo_bindings",
       "//base",
       "//mojo/public/cpp/bindings",
       "//ui/gfx",
     ]
 
     defines = [ "DEVICE_VR_IMPLEMENTATION" ]
-
-    if (is_android) {
+    if (is_android && (current_cpu == "arm" || current_cpu == "arm64")) {
       sources += [
         "android/gvr/gvr_delegate.cc",
         "android/gvr/gvr_delegate.h",
         "android/gvr/gvr_device.cc",
         "android/gvr/gvr_device.h",
         "android/gvr/gvr_device_provider.cc",
         "android/gvr/gvr_device_provider.h",
         "android/gvr/gvr_gamepad_data_fetcher.cc",
         "android/gvr/gvr_gamepad_data_fetcher.h",
       ]
@@ skipping 22 matching lines @@
       "test/fake_vr_service_client.h",
     ]
 
     public_deps = [
       ":mojo_bindings",
       ":vr",
       "//base",
       "//mojo/public/cpp/bindings",
     ]
   }
+} else {
+  component("mojo_only") {
+    sources = [
+      # We need to include an empty .cc file so that mac and windows don't fall over when trying to
+      # compile this.
+      "empty.cc",
+      "vr_export.h",
+    ]
+    defines = [ "DEVICE_VR_IMPLEMENTATION" ]
+    public_deps = [
+      ":mojo_bindings",
+    ]
+  }
 }
 
 mojom("mojo_bindings") {
   sources = [
     "vr_service.mojom",
   ]
+
+  public_deps = [
+    "//mojo/common:common_custom_types",
+  ]
+
+  export_class_attribute = "DEVICE_VR_EXPORT"
+  export_define = "DEVICE_VR_IMPLEMENTATION=1"
+  export_header = "device/vr/vr_export.h"
 }