Test refactors to allow for delaying response trailers.

net/tools/quic/quic_simple_server_stream.cc

Index: net/tools/quic/quic_simple_server_stream.cc
diff --git a/net/tools/quic/quic_simple_server_stream.cc b/net/tools/quic/quic_simple_server_stream.cc
index 8b10b752f12515b3b6719cc4f5160ea3d7b1270b..cd4e5ef135fef9225f4c65f8629086ab88324a48 100644
--- a/net/tools/quic/quic_simple_server_stream.cc
+++ b/net/tools/quic/quic_simple_server_stream.cc
@@ -28,9 +28,7 @@ namespace net {
 
 QuicSimpleServerStream::QuicSimpleServerStream(QuicStreamId id,
                                                QuicSpdySession* session)
-    : QuicSpdyStream(id, session),
-      content_length_(-1),
-      response_started_(false) {}
+    : QuicSpdyStream(id, session), content_length_(-1) {}
 
 QuicSimpleServerStream::~QuicSimpleServerStream() {}
 
@@ -105,10 +103,7 @@ void QuicSimpleServerStream::OnDataAvailable() {
     return;
   }
 
-  // Subclass could have manually invoked SendResponse earlier.
-  if (!response_started_) {
-    SendResponse();
-  }
+  SendResponse();
 }
 
 void QuicSimpleServerStream::PushResponse(
@@ -127,9 +122,6 @@ void QuicSimpleServerStream::PushResponse(
 }
 
 void QuicSimpleServerStream::SendResponse() {
-  DCHECK(!response_started_);
-  response_started_ = true;
-
   if (request_headers_.empty()) {
     DVLOG(1) << "Request headers empty.";
     SendErrorResponse();