Decouple VR Shell DPR and CSS size from Physical Displays.

content/browser/renderer_host/render_widget_host_view_android.cc

Index: content/browser/renderer_host/render_widget_host_view_android.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index 9e33733cc4b55e355ebe6a7236dd285ac4695e6c..24432ff2614d5378f2b5085e3cb29fd8f1ad9555 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -556,7 +556,7 @@ void RenderWidgetHostViewAndroid::GetScaledContentBitmap(
   DCHECK_LE(src_subrect.width() + src_subrect.x(), bounds.width());
   DCHECK_LE(src_subrect.height() + src_subrect.y(), bounds.height());
   const display::Display& display =
-      display::Screen::GetScreen()->GetPrimaryDisplay();
+      display::Screen::GetScreen()->GetDisplayNearestWindow(GetNativeView());
   float device_scale_factor = display.device_scale_factor();
   DCHECK_GT(device_scale_factor, 0);
   gfx::Size dst_size(
@@ -989,7 +989,7 @@ void RenderWidgetHostViewAndroid::CopyFromCompositingSurface(
 
   base::TimeTicks start_time = base::TimeTicks::Now();
   const display::Display& display =
-      display::Screen::GetScreen()->GetPrimaryDisplay();
+      display::Screen::GetScreen()->GetDisplayNearestWindow(GetNativeView());
   float device_scale_factor = display.device_scale_factor();
   gfx::Size dst_size_in_pixel =
       gfx::ConvertRectToPixel(device_scale_factor, gfx::Rect(dst_size)).size();