Decouple VR Shell DPR and CSS size from Physical Displays.

chrome/browser/resources/vr_shell/vr_shell_ui_api.js

Index: chrome/browser/resources/vr_shell/vr_shell_ui_api.js
diff --git a/chrome/browser/resources/vr_shell/vr_shell_ui_api.js b/chrome/browser/resources/vr_shell/vr_shell_ui_api.js
index 8e2fca19573b11132be1c014c3eda7df38f803f0..de8c7fa3071bc7e3b9150e545512e1e117441951 100644
--- a/chrome/browser/resources/vr_shell/vr_shell_ui_api.js
+++ b/chrome/browser/resources/vr_shell/vr_shell_ui_api.js
@@ -101,6 +101,13 @@ var api = (function() {
   }
 
   /**
+   * Sets the CSS size for this page.
+   */
+  function setUiCssSize(width, height, dpr) {
+    chrome.send('setUiCssSize', [width, height, dpr]);
+  }
+
+  /**
    * Represents updates to UI element properties. Any properties set on this
    * object are relayed to an underlying native element via scene command.
    * Properties that are not set on this object are left unchanged.
@@ -306,5 +313,6 @@ var api = (function() {
     Animation: Animation,
     doAction: doAction,
     domLoaded: domLoaded,
+    setCssSize: setCssSize,
   };
 })();