Ozone GBM: support R_8 format to GpuMemoryBuffers

ui/ozone/platform/drm/client_native_pixmap_factory_gbm.cc

 // Copyright 2015 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.
 
 #include "ui/ozone/platform/drm/client_native_pixmap_factory_gbm.h"
 
 #include <utility>
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
@@ skipping 31 matching lines @@
     switch (usage) {
       case gfx::BufferUsage::GPU_READ:
       case gfx::BufferUsage::SCANOUT:
         return format == gfx::BufferFormat::RGBA_8888 ||
                format == gfx::BufferFormat::RGBX_8888 ||
                format == gfx::BufferFormat::BGRA_8888 ||
                format == gfx::BufferFormat::BGRX_8888;
       case gfx::BufferUsage::GPU_READ_CPU_READ_WRITE:
       case gfx::BufferUsage::GPU_READ_CPU_READ_WRITE_PERSISTENT: {
 #if defined(OS_CHROMEOS)
-        return format == gfx::BufferFormat::BGRA_8888;
+        return
+#if defined(ARCH_CPU_X86_FAMILY)

[reveman, 2016/05/05 09:29:24]

what does it take to not have this ifdef? ie. what's missing to support this on
all devices that support native GMBs.

[dshwang, 2016/05/05 12:22:13]

gbm bo creation fails on ARM device.

ARM has to support R8 format in the 3D driver. e.g. Mesa
https://lists.freedesktop.org/archives/mesa-commit/2015-July/057676.html

+            // Currently only Intel driver (i.e. minigbm and Mesa) supports R_8.
+            // crbug.com/356871
+            format == gfx::BufferFormat::R_8 ||
+#endif
+            format == gfx::BufferFormat::BGRA_8888;
 #else
         return false;
 #endif
       }
     }
     NOTREACHED();
     return false;
   }
   std::unique_ptr<ClientNativePixmap> ImportFromHandle(
       const gfx::NativePixmapHandle& handle,
@@ skipping 21 matching lines @@
   }
 
   DISALLOW_COPY_AND_ASSIGN(ClientNativePixmapFactoryGbm);
 };
 
 ClientNativePixmapFactory* CreateClientNativePixmapFactoryGbm() {
   return new ClientNativePixmapFactoryGbm();
 }
 
 }  // namespace ui