Requirements
qmake.exe folder to system pathpython.exe folder to system pathgit.exe folder to system pathgperf.exe folder to system pathwin_bison.exe folder to system path, and rename it to bison.exeNote: I didn't test for Visual Studio versions, all Qt versions.. Let's just take an example here, other versions should be about the same.
Steps to build
ROOTDeveloper Command Prompt for VS2013, and go to ROOT folderqmake WEBENGINE_CONFIG+=use_proprietary_codecs qtwebengine.pro. We add this flag to enable mp3 support.nmakeNote: Mp3 is not supported by QtWebEngine by default, due to license issue. Please make sure to get a license for the codec you added.