Add NativePixmapHandle type & interface for exporting them

ui/ozone/public/client_native_pixmap_factory.h

Index: ui/ozone/public/client_native_pixmap_factory.h
diff --git a/ui/ozone/public/client_native_pixmap_factory.h b/ui/ozone/public/client_native_pixmap_factory.h
index 1f216018d19b99818273b6db1bf2e482cb3ea4b4..7005e1cee564a7acc0bff0712eb8c06327d698f1 100644
--- a/ui/ozone/public/client_native_pixmap_factory.h
+++ b/ui/ozone/public/client_native_pixmap_factory.h
@@ -9,10 +9,14 @@
 
 #include "base/memory/scoped_ptr.h"
 #include "ui/gfx/buffer_types.h"
-#include "ui/gfx/geometry/size.h"
 #include "ui/ozone/ozone_export.h"
 #include "ui/ozone/public/client_native_pixmap.h"
 
+namespace gfx {
+struct NativePixmapHandle;
+class Size;
+}
+
 namespace base {
 
 struct FileDescriptor;
@@ -42,8 +46,9 @@ class OZONE_EXPORT ClientNativePixmapFactory {
 
   // TODO(dshwang): implement it. crbug.com/475633
   // Import the native pixmap from |handle| to be used in non-GPU processes.
-  virtual scoped_ptr<ClientNativePixmap> ImportNativePixmap(
-      const base::FileDescriptor& handle,
+  // This function takes ownership of any file descriptors in |handle|.
+  virtual scoped_ptr<ClientNativePixmap> ImportFromHandle(
+      const gfx::NativePixmapHandle& handle,
       const gfx::Size& size,
       gfx::BufferFormat format,
       gfx::BufferUsage usage) = 0;