Change wxWebRequest and related objects to hide ref counting

Don't force the application code to deal with wxObjectDataPtr<> or,
worse, calling {Inc,Dec}Ref() manually by hiding it inside the wx
objects themselves and giving the value-like semantics to them.

There should be no real changes in the behaviour, but the API does
change significantly. Notably, wxWebRequest is not a wxEvtHandler itself
any longer, as this would be incompatible with the value semantics, and
an event handler needs to be specified when creating it, so that it
could be notified about the request state changes.

include/wx/osx/private/webrequest_urlsession.h

@@ -19,12 +19,13 @@ DECLARE_WXCOCOA_OBJC_CLASS(NSURLSessionTask);
 DECLARE_WXCOCOA_OBJC_CLASS(wxWebSessionDelegate);
 
 class wxWebSessionURLSession;
+class wxWebRequestURLSession;
 class wxWebResponseURLSession;
 
-class WXDLLIMPEXP_NET wxWebResponseURLSession : public wxWebResponse
+class wxWebResponseURLSession : public wxWebResponseImpl
 {
 public:
-    wxWebResponseURLSession(wxWebRequest& request, WX_NSURLSessionTask task);
+    wxWebResponseURLSession(wxWebRequestURLSession& request, WX_NSURLSessionTask task);
 
     ~wxWebResponseURLSession();
 
@@ -44,12 +45,18 @@ public:
 
 private:
     WX_NSURLSessionTask m_task;
+
+    wxDECLARE_NO_COPY_CLASS(wxWebResponseURLSession);
 };
 
-class WXDLLIMPEXP_NET wxWebRequestURLSession : public wxWebRequest
+class wxWebRequestURLSession : public wxWebRequestImpl
 {
 public:
-    wxWebRequestURLSession(wxWebSessionURLSession& session, const wxString& url, int id);
+    wxWebRequestURLSession(wxWebSession& session,
+                           wxWebSessionURLSession& sessionImpl,
+                           wxEvtHandler* handler,
+                           const wxString& url,
+                           int winid);
 
     ~wxWebRequestURLSession();
 
@@ -57,10 +64,10 @@ public:
 
     void Cancel() wxOVERRIDE;
 
-    wxWebResponse* GetResponse() const wxOVERRIDE
-    { return m_response.get(); }
+    wxWebResponseImplPtr GetResponse() const wxOVERRIDE
+        { return m_response; }
 
-    wxWebAuthChallenge* GetAuthChallenge() const wxOVERRIDE;
+    wxWebAuthChallengeImplPtr GetAuthChallenge() const wxOVERRIDE;
 
     wxFileOffset GetBytesSent() const wxOVERRIDE;
 
@@ -72,22 +79,30 @@ public:
 
     void HandleCompletion();
 
+    wxWebResponseURLSession* GetResponseImplPtr() const
+        { return m_response.get(); }
+
 private:
+    wxWebSessionURLSession& m_sessionImpl;
     wxString m_url;
     WX_NSURLSessionTask m_task;
-    wxScopedPtr<wxWebResponseURLSession> m_response;
+    wxObjectDataPtr<wxWebResponseURLSession> m_response;
 
     wxDECLARE_NO_COPY_CLASS(wxWebRequestURLSession);
 };
 
-class WXDLLIMPEXP_NET wxWebSessionURLSession : public wxWebSession
+class wxWebSessionURLSession : public wxWebSessionImpl
 {
 public:
     wxWebSessionURLSession();
 
     ~wxWebSessionURLSession();
 
-    wxWebRequest* CreateRequest(const wxString& url, int id = wxID_ANY) wxOVERRIDE;
+    wxWebRequestImplPtr
+    CreateRequest(wxWebSession& session,
+                  wxEvtHandler* handler,
+                  const wxString& url,
+                  int winid = wxID_ANY) wxOVERRIDE;
 
     wxVersionInfo GetLibraryVersionInfo() wxOVERRIDE;
 
@@ -102,10 +117,10 @@ private:
     wxDECLARE_NO_COPY_CLASS(wxWebSessionURLSession);
 };
 
-class WXDLLIMPEXP_NET wxWebSessionFactoryURLSession : public wxWebSessionFactory
+class wxWebSessionFactoryURLSession : public wxWebSessionFactory
 {
 public:
-    wxWebSession* Create() wxOVERRIDE
+    wxWebSessionImpl* Create() wxOVERRIDE
     { return new wxWebSessionURLSession(); }
 };