Issue #4694 - Add mutex protection to JS event handling

libadblockplus.gyp

 {
   'conditions': [[
     # We don't want to use curl on Windows and Android, skip the check there
     'OS=="win" or OS=="android"',
     {
       'variables': {
         'have_curl': 0
       }
     },
     {
@@ skipping 38 matching lines @@
       'include/AdblockPlus/ReferrerMapping.h',
       'include/AdblockPlus/WebRequest.h',
       'src/AllocatedArray.h',
       'src/AppInfoJsObject.cpp',
       'src/AppInfoJsObject.h',
       'src/ConsoleJsObject.cpp',
       'src/ConsoleJsObject.h',
       'src/DefaultLogSystem.cpp',
       'src/DefaultFileSystem.cpp',
       'src/DefaultWebRequestWinInet.h',
+      'src/Event.cpp',
+      'src/Event.h',
       'src/FileSystemJsObject.cpp',
       'src/FileSystemJsObject.h',
       'src/FilterEngine.cpp',
       'src/GlobalJsObject.cpp',
       'src/GlobalJsObject.h',
       'src/JsContext.cpp',
       'src/JsContext.h',
       'src/JsEngine.cpp',
       'src/JsEngineInternal.h',
       'src/JsEngineTransition.h',
@@ skipping 141 matching lines @@
       'test/WebRequest.cpp'
     ],
     'msvs_settings': {
       'VCLinkerTool': {
         'SubSystem': '1',   # Console
         'EntryPointSymbol': 'mainCRTStartup',
       },
     },
   }]
 }