Move SkTDArray to private.

TBR=reed
Moving to private is good.

Review URL: https://codereview.chromium.org/1707213002
diff --git a/tools/flags/SkCommandLineFlags.h b/tools/flags/SkCommandLineFlags.h
index a2d3ba9..78919c1 100644
--- a/tools/flags/SkCommandLineFlags.h
+++ b/tools/flags/SkCommandLineFlags.h
@@ -9,8 +9,8 @@
 #define SK_COMMAND_LINE_FLAGS_H
 
 #include "../private/SkTArray.h"
+#include "../private/SkTDArray.h"
 #include "SkString.h"
-#include "SkTDArray.h"
 
 /**
  *  Including this file (and compiling SkCommandLineFlags.cpp) provides command line