Add VR Shell animation classes and unit test.

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 3dfc8c6fb931b7ddcce342658924f071dd373f5f..2dabb502e2e13c0071df838d467f6b6cb6fa486e 100644
--- a/chrome/browser/android/vr_shell/BUILD.gn
+++ b/chrome/browser/android/vr_shell/BUILD.gn
@@ -4,19 +4,26 @@
 
 import("//build/config/android/rules.gni")
 import("//chrome/common/features.gni")
+import("//testing/test.gni")
 
 assert(enable_vr_shell && android_java_ui)
 
 static_library("vr_shell") {
   sources = [
+    "animation.cc",
+    "animation.h",
+    "easing.cc",
+    "easing.h",
     "ui_elements.cc",
     "ui_elements.h",
+    "vr_gl_util.cc",
+    "vr_gl_util.h",
+    "vr_math.cc",
+    "vr_math.h",
     "vr_shell.cc",
     "vr_shell.h",
     "vr_shell_renderer.cc",
     "vr_shell_renderer.h",
-    "vr_util.cc",
-    "vr_util.h",
   ]
 
   deps = [
@@ -39,3 +46,17 @@ generate_jni("vr_shell_jni_headers") {
   ]
   jni_package = "vr_shell"
 }
+
+test("vr_shell_unittests") {
+  sources = [
+    "ui_elements_unittest.cc",
+  ]
+
+  deps = [
+    ":vr_shell",
+    "//base/test:run_all_unittests",
+    "//base/test:test_support",
+    "//testing/gtest",
+    "//ui/gfx/geometry",
+  ]
+}