[Ozone-Dri] Replace blend with copy to the modeset buffer

ui/ozone/platform/dri/screen_manager.cc

Index: ui/ozone/platform/dri/screen_manager.cc
diff --git a/ui/ozone/platform/dri/screen_manager.cc b/ui/ozone/platform/dri/screen_manager.cc
index 2a1eaeca91bbc85367322695050f1d1a5fc69281..fbf2edef55a95c9e75e694eb09fd5958aaf98bfe 100644
--- a/ui/ozone/platform/dri/screen_manager.cc
+++ b/ui/ozone/platform/dri/screen_manager.cc
@@ -54,7 +54,10 @@ void FillModesetBuffer(const scoped_refptr<DriWrapper>& dri,
     return;
 
   skia::RefPtr<SkImage> image = saved_buffer.image();
-  modeset_buffer.canvas()->drawImage(image.get(), 0, 0);
+  SkPaint paint;
+  // Copy the source buffer. Do not perform any blending.
+  paint.setXfermodeMode(SkXfermode::kSrc_Mode);
+  modeset_buffer.canvas()->drawImage(image.get(), 0, 0, &paint);
 }
 
 }  // namespace