Create Response namespace for skiaserve response functions

tools/skiaserve/Response.h

+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef Reponse_DEFINED
+#define Reponse_DEFINED
+
+struct MHD_Connection;
+struct Request;
+class SkData;
+
+namespace Response {
+    // SendOK just sends an empty response with a 200 OK status code.
+    int SendOK(MHD_Connection* connection);
+
+    int SendError(MHD_Connection* connection, const char* msg);
+
+    int SendData(MHD_Connection* connection, const SkData* data, const char* type,
+                 bool setContentDisposition = false, const char* dispositionString = nullptr);
+
+    int SendJSON(MHD_Connection* connection, Request* request, int n);
+
+    int SendTemplate(MHD_Connection* connection, bool redirect = false,
+                     const char* redirectUrl = nullptr);
+}
+
+#endif