Remove unnecessary UI element math.

chrome/browser/android/vr_shell/ui_scene.h

Index: chrome/browser/android/vr_shell/ui_scene.h
diff --git a/chrome/browser/android/vr_shell/ui_scene.h b/chrome/browser/android/vr_shell/ui_scene.h
index 7c63c6e46bd7c453f8231d8c7322e1b5225e87e6..cea660d85d6cf1121602fe1846abb39e2a9db272 100644
--- a/chrome/browser/android/vr_shell/ui_scene.h
+++ b/chrome/browser/android/vr_shell/ui_scene.h
@@ -20,7 +20,7 @@ namespace vr_shell {
 
 class Animation;
 struct ContentRectangle;
-struct ReversibleTransform;
+struct Transform;
 
 class UiScene {
  public:
@@ -59,9 +59,9 @@ class UiScene {
   void UpdateBackgroundFromDict(const base::DictionaryValue& dict);
 
   // Update the positions of all elements in the scene, according to active
-  // animations, desired screen tilt and time.  The units of time are
-  // arbitrary, but must match the unit used in animations.
-  void UpdateTransforms(float screen_tilt, int64_t time_in_micro);
+  // animations and time.  The units of time are arbitrary, but must match the
+  // unit used in animations.
+  void UpdateTransforms(int64_t time_in_micro);
 
   // Handle a batch of commands passed from the UI HTML.
   void HandleCommands(std::unique_ptr<base::ListValue> commands,
@@ -76,7 +76,7 @@ class UiScene {
 
  private:
   void ApplyRecursiveTransforms(const ContentRectangle& element,
-                                ReversibleTransform* transform,
+                                Transform* transform,
                                 float* opacity);
   void ApplyDictToElement(const base::DictionaryValue& dict,
                           ContentRectangle* element);