[vr] Add a frame rate counter for the vr UI

chrome/browser/android/vr_shell/BUILD.gn

Index: chrome/browser/android/vr_shell/BUILD.gn
diff --git a/chrome/browser/android/vr_shell/BUILD.gn b/chrome/browser/android/vr_shell/BUILD.gn
index 753ae749e39d560e9d037c12c66df23f35d5a338..be718d129977134248153e3f6b36eee8434c2ce2 100644
--- a/chrome/browser/android/vr_shell/BUILD.gn
+++ b/chrome/browser/android/vr_shell/BUILD.gn
@@ -20,6 +20,8 @@ if (current_cpu == "arm" || current_cpu == "arm64") {
       "animation.h",
       "easing.cc",
       "easing.h",
+      "fps_meter.cc",
+      "fps_meter.h",
       "gltf_asset.cc",
       "gltf_asset.h",
       "gltf_parser.cc",
@@ -109,6 +111,7 @@ if (current_cpu == "arm" || current_cpu == "arm64") {
 if (enable_vr) {
   test("vr_shell_unittests") {
     sources = [
+      "fps_meter_unittest.cc",
       "gltf_parser_unittest.cc",
       "test/paths.cc",
       "test/paths.h",
@@ -128,9 +131,8 @@ if (enable_vr) {
 
     # Ensure libgvr static library appears before gcc library in linking order.
     # See https://crbug.com/704305 for details.
-    libs = [
-      "//third_party/gvr-android-sdk/libgvr_shim_static_${current_cpu}.a",
-    ]
+    libs =
+        [ "//third_party/gvr-android-sdk/libgvr_shim_static_${current_cpu}.a" ]
 
     data = [
       "test/data/sample_inline.gltf",