ozone: Create GbmBuffers from fourcc formats and gbm flags.

ui/ozone/platform/drm/gpu/screen_manager_unittest.cc

Index: ui/ozone/platform/drm/gpu/screen_manager_unittest.cc
diff --git a/ui/ozone/platform/drm/gpu/screen_manager_unittest.cc b/ui/ozone/platform/drm/gpu/screen_manager_unittest.cc
index 5e009fddef2d81fe0b127d9c698a1edba8508b79..c35b3808ccbdf90115917cbcfea8eff747de4763 100644
--- a/ui/ozone/platform/drm/gpu/screen_manager_unittest.cc
+++ b/ui/ozone/platform/drm/gpu/screen_manager_unittest.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <drm_fourcc.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ -499,7 +500,7 @@ TEST_F(ScreenManagerTest, EnableControllerWhenWindowHasBuffer) {
   window->Initialize(buffer_generator_.get());
   window->SetBounds(GetPrimaryBounds());
   scoped_refptr<ui::ScanoutBuffer> buffer = buffer_generator_->Create(
-      drm_, gfx::BufferFormat::BGRA_8888, GetPrimaryBounds().size());
+      drm_, DRM_FORMAT_XRGB8888, GetPrimaryBounds().size());

[tfiga, 2016/12/06 07:20:37]

Shouldn't the new format be DRM_FORMAT_ARGB8888?

[Daniele Castagna, 2016/12/06 18:31:10]

At this point Chrome doesn't support overlays with alpha. That means if a gfx
format with alpha arrives here we know we can discard the alpha channel and we
use a fourcc format without alpha to create the framebuffer. You can see that in
drm_util.cc GetFourCCFormatForFramebuffer.

Since we changed the gbmbuffer format from gfx::BufferFormat to a fourcc format,
this change reflects that.

   window->SchedulePageFlip(
       std::vector<ui::OverlayPlane>(1, ui::OverlayPlane(buffer)),
       base::Bind(&EmptySwapCallback));