Improve inheritance support in the CEF API (issue #1623).

- Support single parent inheritance in CEF API classes.
- Support non-virtual inheritance in CEF API classes.
- Support translation of CEF API sub-directories.
- Add test sub-directories for testing-only functionality that will be
  available to unit tests but not exposed via the binary distribution.
- Add unit tests for the translator tool.
- Fix parsing of template parameter types that include commas.

libcef_dll/ctocpp/request_handler_ctocpp.h

@@ -28,11 +28,9 @@ class CefRequestHandlerCToCpp
     : public CefCToCpp<CefRequestHandlerCToCpp, CefRequestHandler,
         cef_request_handler_t> {
  public:
-  explicit CefRequestHandlerCToCpp(cef_request_handler_t* str)
-      : CefCToCpp<CefRequestHandlerCToCpp, CefRequestHandler,
-          cef_request_handler_t>(str) {}
+  CefRequestHandlerCToCpp();
 
-  // CefRequestHandler methods
+  // CefRequestHandler methods.
   bool OnBeforeBrowse(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame,
       CefRefPtr<CefRequest> request, bool is_redirect) override;
   bool OnOpenURLFromTab(CefRefPtr<CefBrowser> browser,
@@ -74,4 +72,3 @@ class CefRequestHandlerCToCpp
 
 #endif  // BUILDING_CEF_SHARED
 #endif  // CEF_LIBCEF_DLL_CTOCPP_REQUEST_HANDLER_CTOCPP_H_
-