Call CefDoMessageLoopWork() even more aggressively

Calling this function from OnInternalIdle() is not always enough, so
call it before processing each and every event to ensure that CEF can
really do whatever it needs to be doing internally.

This doesn't seem to noticeably slow down the program and solves weird
problems, like embedded text boxes (e.g. search zones on the web sites)
not getting focus on click.

include/wx/webview_chromium.h

@@ -132,8 +132,6 @@ public:
     virtual void GTKHandleRealized() override;
 #endif
 
-    virtual void OnInternalIdle() override;
-
 protected:
     virtual void DoSetPage(const wxString& html, const wxString& baseUrl) override;