Allow the VR omnibox to be transient.

chrome/browser/resources/vr_shell/vr_shell_ui.css

Index: chrome/browser/resources/vr_shell/vr_shell_ui.css
diff --git a/chrome/browser/resources/vr_shell/vr_shell_ui.css b/chrome/browser/resources/vr_shell/vr_shell_ui.css
index 07daf35f377ba028e087079d67356722347bb27f..b0ad92bbbfc89dd0b04bc8f3961053ad40c62f0f 100644
--- a/chrome/browser/resources/vr_shell/vr_shell_ui.css
+++ b/chrome/browser/resources/vr_shell/vr_shell_ui.css
@@ -139,10 +139,13 @@ html {
   padding: 12px;
 }
 
-#omni {
+#omni-container {
   --tranX: 0;
-  --tranY: -0.5;
-  --tranZ: -1.0;
+  --tranY: -0.65;
+  --tranZ: -1.2;
+}
+
+#omni {
   align-items: center;
   background-color: rgba(255, 255, 255, 0.9);
   border-radius: 100px;
@@ -153,7 +156,7 @@ html {
   margin-bottom: 60px;
   margin-top: 0;
   opacity: 1;
-  transition: opacity 250ms ease, margin-top 250ms ease;
+  transition: opacity 500ms ease, margin-top 500ms ease;
   white-space: nowrap;
   width: 512px;
 }