Add passive and FOV-locked properties to UI elements.

chrome/browser/android/vr_shell/ui_elements.h

Index: chrome/browser/android/vr_shell/ui_elements.h
diff --git a/chrome/browser/android/vr_shell/ui_elements.h b/chrome/browser/android/vr_shell/ui_elements.h
index 7316eaa34cd2d97c01702426e30582d14c6de857..2edf2173347cdbce9f7aac6b5b2b179af2fb720e 100644
--- a/chrome/browser/android/vr_shell/ui_elements.h
+++ b/chrome/browser/android/vr_shell/ui_elements.h
@@ -73,6 +73,13 @@ struct ContentRectangle : public WorldRectangle {
   // If true, this object will be visible and accept input.
   bool visible = true;
 
+  // If true, input will be ignored, even if visible.
+  bool passive = false;

[mthiesse, 2016/10/20 18:15:31]

I think a more common property would be something like hit_test_visible or
hit_test_enabled. Passive isn't very descriptive.

[cjgrant, 2016/10/21 14:14:50]

Done.

+
+  // If true, transformations will be applied relative to the field of view,
+  // rather than the world.
+  bool lock_to_fov = false;
+
   // Specifies the region (in pixels) of a texture to render.
   Recti copy_rect = {0, 0, 0, 0};