Adds in-out easing type.

chrome/browser/resources/vr_shell/vr_shell_ui.js

Index: chrome/browser/resources/vr_shell/vr_shell_ui.js
diff --git a/chrome/browser/resources/vr_shell/vr_shell_ui.js b/chrome/browser/resources/vr_shell/vr_shell_ui.js
index d7d407d2cc403fcb7ffcd94fd01109b42e469393..360323a62c3d91c0bfbf2af0558f32d66f7b0f20 100644
--- a/chrome/browser/resources/vr_shell/vr_shell_ui.js
+++ b/chrome/browser/resources/vr_shell/vr_shell_ui.js
@@ -96,10 +96,11 @@ var vrShellUi = (function() {
       let anim;
       anim = new api.Animation(this.elementId, ANIM_DURATION);
       anim.setTranslation(0, y, z);
+      anim.setEasing(new api.InOutEasing(2));

[cjgrant, 2017/02/16 15:10:25]

We should probably have a module level constant EASING or EASING_POWER in place
of '2'.

[tiborg, 2017/02/16 18:39:33]

Set default values for the easing. So, we don't need the number here anymore.

[cjgrant, 2017/02/16 20:54:07]

Acknowledged.

       ui.addAnimation(anim);
       anim = new api.Animation(this.elementId, ANIM_DURATION);
       anim.setSize(height * this.SCREEN_RATIO, height);
-      anim.setEasing(new api.InEasing(2));
+      anim.setEasing(new api.InOutEasing(2));
       ui.addAnimation(anim);
     }