cc: Add gfx::BufferFormat to cc::ResourceProvider::Resource.

cc/resources/transferable_resource.h

Index: cc/resources/transferable_resource.h
diff --git a/cc/resources/transferable_resource.h b/cc/resources/transferable_resource.h
index ca623ad3c37a63c6065dd0ac41b9e48eac111cc7..5ff4bb4613edfbe528ac3ec800c5a9daf351a748 100644
--- a/cc/resources/transferable_resource.h
+++ b/cc/resources/transferable_resource.h
@@ -13,6 +13,7 @@
 #include "cc/base/resource_id.h"
 #include "cc/resources/resource_format.h"
 #include "gpu/command_buffer/common/mailbox_holder.h"
+#include "ui/gfx/buffer_types.h"
 #include "ui/gfx/color_space.h"
 #include "ui/gfx/geometry/size.h"
 
@@ -33,7 +34,9 @@ struct CC_EXPORT TransferableResource {
                               ReturnedResourceArray* output);
 
   ResourceId id;
+  // Refer to ResourceProvider::Resource for the meaning of the following data.
   ResourceFormat format;
+  gfx::BufferFormat buffer_format;
   uint32_t filter;
   gfx::Size size;
   gpu::MailboxHolder mailbox_holder;