VrShell: Add test for fullscreen transitions.

chrome/browser/android/vr_shell/ui_elements/ui_element_debug_id.h

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_ANDROID_VR_SHELL_UI_ELEMENTS_UI_ELEMENT_DEBUG_ID_H_
 #define CHROME_BROWSER_ANDROID_VR_SHELL_UI_ELEMENTS_UI_ELEMENT_DEBUG_ID_H_
 
 namespace vr_shell {
 
 // These identifiers may be used by UI elements to tag themselves for purposes
 // of testing or debugging.
 enum UiElementDebugId {
   kNone = 0,
   kWebVrPermanentHttpSecurityWarning,
   kWebVrTransientHttpSecurityWarning,
+  kContentQuad,
+  kCeiling,
+  kFloor,
+  kGrid,

[cjgrant, 2017/05/23 18:58:11]

Maybe kFloorGrid just to be clear?

[amp, 2017/05/23 20:56:02]

Done.  I think I actually refered to it as FloorGrid somewhere else too.

+  kBrowserBar,

[cjgrant, 2017/05/23 18:58:11]

This is called the URL bar everywhere else. kUrlBar?

[amp, 2017/05/23 20:56:02]

Done.

+  kLoadingIndicator,
+  kAudioCaptureIndicator,
+  kVideoCaptureIndicator,
   kCloseButton,
 };
 
 }  // namespace vr_shell
 
 #endif  // CHROME_BROWSER_ANDROID_VR_SHELL_UI_ELEMENTS_UI_ELEMENT_DEBUG_ID_H_