ozone: Implement support for CreateGpuMemoryBufferFromHandle for OzoneNativePixmap backed GMBs.

ui/ozone/platform/drm/gpu/gbm_buffer.h

Index: ui/ozone/platform/drm/gpu/gbm_buffer.h
diff --git a/ui/ozone/platform/drm/gpu/gbm_buffer.h b/ui/ozone/platform/drm/gpu/gbm_buffer.h
index 0c426d7551c5205dfc4eb02495dfd176b3556dfd..4c2f242d314d9d1dd6f90fb26e721d6db83bb8c3 100644
--- a/ui/ozone/platform/drm/gpu/gbm_buffer.h
+++ b/ui/ozone/platform/drm/gpu/gbm_buffer.h
@@ -41,9 +41,9 @@ class GbmBuffer : public GbmBufferBase {
 
 class GbmPixmap : public NativePixmap {
  public:
-  GbmPixmap(const scoped_refptr<GbmBuffer>& buffer,
-            GbmSurfaceFactory* surface_manager);
-  bool Initialize();
+  explicit GbmPixmap(GbmSurfaceFactory* surface_manager);
+  void Initialize(int dma_buf, int dma_buf_pitch);

[spang, 2015/10/09 17:29:21]

I think we should use ScopedFD instead of int here since ownership is
transferred.

[reveman, 2015/10/09 18:45:32]

Done. I also included the GbmPixmap::dma_buf_ change to ScopedFD as it's awkward
to mix.

+  bool InitializeFromBuffer(const scoped_refptr<GbmBuffer>& buffer);
   void SetScalingCallback(const ScalingCallback& scaling_callback) override;
   scoped_refptr<NativePixmap> GetScaledPixmap(gfx::Size new_size) override;
 
@@ -68,6 +68,7 @@ class GbmPixmap : public NativePixmap {
 
   scoped_refptr<GbmBuffer> buffer_;
   int dma_buf_ = -1;
+  int dma_buf_pitch_ = -1;
 
   GbmSurfaceFactory* surface_manager_;