Extract TestFile class in a separate header.

This allows to reuse it in the other tests which need to create a temporary
file automatically destroyed on test exit.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@61897 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

tests/streams/tempfile.cpp

@@ -24,29 +24,7 @@
 
 #if wxUSE_STREAMS && wxUSE_FILE
 
-
-///////////////////////////////////////////////////////////////////////////////
-// Self deleting test file
-
-class TestFile
-{
-public:
-    TestFile();
-    ~TestFile() { if (wxFileExists(m_name)) wxRemoveFile(m_name); }
-    wxString GetName() const { return m_name; }
-private:
-    wxString m_name;
-};
-
-// Initialise with a test pattern so we can see if the file is replaced
-//
-TestFile::TestFile()
-{
-    wxFile file;
-    m_name = wxFileName::CreateTempFileName(wxT("wxtest"), &file);
-    file.Write("Before", 6);
-}
-
+#include "testfile.h"
 
 ///////////////////////////////////////////////////////////////////////////////
 // The test case