Revert "Change content-type for json stream to application/x-json-stream."

This reverts commit 10ab2089ce189d5bea3f7aaac3b5081471309478.

Conflicts:
	api/client/utils.go
	docs/sources/reference/api/docker_remote_api.md

Docker-DCO-1.1-Signed-off-by: Jessica Frazelle <jess@docker.com> (github: jfrazelle)
Upstream-commit: 4c6b7cd1b560c72f2c79c28f77644f05b3ee657e
Component: engine

components/engine/api/server/server.go

@@ -120,10 +120,6 @@ func writeJSON(w http.ResponseWriter, code int, v engine.Env) error {
 
 func streamJSON(job *engine.Job, w http.ResponseWriter, flush bool) {
 	w.Header().Set("Content-Type", "application/json")
-	if job.GetenvBool("lineDelim") {
-		w.Header().Set("Content-Type", "application/x-json-stream")
-	}
-
 	if flush {
 		job.Stdout.Add(utils.NewWriteFlusher(w))
 	} else {
@@ -993,9 +989,6 @@ func postBuild(eng *engine.Engine, version version.Version, w http.ResponseWrite
 		}
 	}
 
-	// This needs to be set before calls to streamJSON
-	job.SetenvBool("lineDelim", version.GreaterThanOrEqualTo("1.15"))
-
 	if version.GreaterThanOrEqualTo("1.8") {
 		job.SetenvBool("json", true)
 		streamJSON(job, w, true)

components/engine/api/server/server_unit_test.go

@@ -275,7 +275,7 @@ func TestGetEvents(t *testing.T) {
 	if !called {
 		t.Fatal("handler was not called")
 	}
-	assertContentType(r, "application/x-json-stream", t)
+	assertContentType(r, "application/json", t)
 	var stdout_json struct {
 		Since int
 		Until int