Change resume token options to be empty interfaces

The ResumeToken property and SetResumeToken method on
options.ChangeStreamOptions now uses an empty interface instead of a
bsonx.Doc.

GODRIVER-644

Change-Id: Ibead5375c64061185d282222f991e83cac9fd693

Author: skriptble

mongo/change_stream.go

@@ -71,7 +71,11 @@ func newChangeStream(ctx context.Context, coll *Collection, pipeline interface{}
 		aggOpts.MaxAwaitTime = csOpts.MaxAwaitTime
 	}
 	if csOpts.ResumeAfter != nil {
-		changeStreamOptions = append(changeStreamOptions, bsonx.Elem{"resumeAfter", bsonx.Document(csOpts.ResumeAfter)})
+		rt, err := transformDocument(coll.registry, csOpts.ResumeAfter)
+		if err != nil {
+			return nil, err
+		}
+		changeStreamOptions = append(changeStreamOptions, bsonx.Elem{"resumeAfter", bsonx.Document(rt)})
 	}
 
 	pipelineArr = append(pipelineArr, bsonx.Val{})

mongo/options/changestreamoptions.go

@@ -8,8 +8,6 @@ package options
 
 import (
 	"time"
-
-	"github.com/mongodb/mongo-go-driver/x/bsonx"
 )
 
 // ChangeStreamOptions represents all possible options to a change stream
@@ -18,7 +16,7 @@ type ChangeStreamOptions struct {
 	Collation    *Collation     // Specifies a collation
 	FullDocument *FullDocument  // When set to ‘updateLookup’, the change notification for partial updates will include both a delta describing the changes to the document, as well as a copy of the entire document that was changed from some time after the change occurred.
 	MaxAwaitTime *time.Duration // The maximum amount of time for the server to wait on new documents to satisfy a change stream query
-	ResumeAfter  bsonx.Doc      // Specifies the logical starting point for the new change stream
+	ResumeAfter  interface{}    // Specifies the logical starting point for the new change stream
 }
 
 // ChangeStream returns a pointer to a new ChangeStreamOptions
@@ -55,8 +53,8 @@ func (cso *ChangeStreamOptions) SetMaxAwaitTime(d time.Duration) *ChangeStreamOp
 }
 
 // SetResumeAfter specifies the logical starting point for the new change stream
-func (cso *ChangeStreamOptions) SetResumeAfter(d bsonx.Doc) *ChangeStreamOptions {
-	cso.ResumeAfter = d
+func (cso *ChangeStreamOptions) SetResumeAfter(rt interface{}) *ChangeStreamOptions {
+	cso.ResumeAfter = rt
 	return cso
 }