Add initial dump() method to NetdNativeService

This is called by "dumpsys netd".

Bug: 27239233
Change-Id: I27fb308f8067243ff241a6f8fd6a83f406087d2a
diff --git a/server/DumpWriter.h b/server/DumpWriter.h
new file mode 100644
index 0000000..3bdad4f
--- /dev/null
+++ b/server/DumpWriter.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef NETD_SERVER_DUMPWRITER_H_
+#define NETD_SERVER_DUMPWRITER_H_
+
+#include <string>
+#include <utils/String16.h>
+#include <utils/Vector.h>
+
+
+class DumpWriter {
+public:
+    DumpWriter(int fd);
+
+    void incIndent();
+    void decIndent();
+
+    void println(const std::string& line);
+    void println(const char* fmt, ...);
+    void blankline() { println(""); }
+
+private:
+    uint8_t mIndentLevel;
+    int mFd;
+};
+
+#endif  // NETD_SERVER_DUMPWRITER_H_