Document fullscreen/ESC behaviour.

chrome/common/extensions/api/app_window.idl

Index: chrome/common/extensions/api/app_window.idl
diff --git a/chrome/common/extensions/api/app_window.idl b/chrome/common/extensions/api/app_window.idl
index 9b3dabd9a4dda55613c57a8eeff2def3c4b28ef2..9f6a6acb7992efff7cb3fef7a4754139a0c2f84b 100644
--- a/chrome/common/extensions/api/app_window.idl
+++ b/chrome/common/extensions/api/app_window.idl
@@ -135,7 +135,13 @@ namespace app.window {
     // Focus the window.
     static void focus();
 
-    // Fullscreens the window.
+    // Fullscreens the window.<br>
+    // The user will be able to restore the window by pressing ESC. An
+    // application can prevent the fullscreen state to be left when ESC is
+    // pressed by requesting the <b>overrideEscFullscreen</b> permission and
+    // canceling the event by calling .preventDefault(), like this:<br>
+    // <code>window.onKeyDown = function(e) { if (e.keyCode == 27 /* ESC */) {
+    // e.preventDefault(); } };</code>
     static void fullscreen();
 
     // Is the window fullscreen?