Do not use overlays when VR shell is enabled.

content/public/common/screen_info.h

 // Copyright 2016 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 CONTENT_PUBLIC_COMMON_SCREEN_INFO_H_
 #define CONTENT_PUBLIC_COMMON_SCREEN_INFO_H_
 
 #include "content/common/content_export.h"
 #include "content/public/common/screen_orientation_values.h"
 #include "ui/gfx/geometry/rect.h"
@@ skipping 18 matching lines @@
     // The screen depth in bits per pixel
     uint32_t depth = 0;
 
     // The bits per colour component. This assumes that the colours are balanced
     // equally.
     uint32_t depth_per_component = 0;
 
     // This can be true for black and white printers
     bool is_monochrome = false;
 
+    // This is true when display is a virtual display.
+    bool in_vr = false;
+
     // The display monitor rectangle in virtual-screen coordinates. Note that
     // this may be negative.
     gfx::Rect rect;
 
     // The portion of the monitor's rectangle that can be used by applications.
     gfx::Rect available_rect;
 
     // The monitor's orientation.
     ScreenOrientationValues orientation_type =
         SCREEN_ORIENTATION_VALUES_DEFAULT;
 
     // This is the orientation angle of the displayed content in degrees.
     // It is the opposite of the physical rotation.
     uint16_t orientation_angle = 0;
 
     bool operator==(const ScreenInfo& other) const;
     bool operator!=(const ScreenInfo& other) const;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_COMMON_SCREEN_INFO_H_