ozone: Add an opaque fb to ScanoutBuffer for primary planes.

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

Index: ui/ozone/platform/drm/gpu/gbm_buffer_base.h
diff --git a/ui/ozone/platform/drm/gpu/gbm_buffer_base.h b/ui/ozone/platform/drm/gpu/gbm_buffer_base.h
index a4732c75f9cbaa52afca5c83685f786555b2431b..1aca1bb7fac4bd35bea0ef2e5af7e0580d196388 100644
--- a/ui/ozone/platform/drm/gpu/gbm_buffer_base.h
+++ b/ui/ozone/platform/drm/gpu/gbm_buffer_base.h
@@ -27,9 +27,11 @@ class GbmBufferBase : public ScanoutBuffer {
 
   // ScanoutBuffer:
   uint32_t GetFramebufferId() const override;
+  uint32_t GetOpaqueFramebufferId() const override;
   uint32_t GetHandle() const override;
   gfx::Size GetSize() const override;
   uint32_t GetFramebufferPixelFormat() const override;
+  uint32_t GetOpaqueFramebufferPixelFormat() const override;
   const DrmDevice* GetDrmDevice() const override;
   bool RequiresGlFinish() const override;
 
@@ -47,6 +49,11 @@ class GbmBufferBase : public ScanoutBuffer {
   gbm_bo* bo_;
   uint32_t framebuffer_ = 0;
   uint32_t framebuffer_pixel_format_ = 0;
+  // If |opaque_framebuffer_pixel_format_| differs from
+  // |framebuffer_pixel_format_| the following member is set to a valid fb,
+  // otherwise it is set to 0.
+  uint32_t opaque_framebuffer_ = 0;
+  uint32_t opaque_framebuffer_pixel_format_ = 0;
 
   DISALLOW_COPY_AND_ASSIGN(GbmBufferBase);
 };