fix build when ffmpeg, libvpx and libwebm are disabled

chrome/utility/extensions/extensions_handler.cc

Index: chrome/utility/extensions/extensions_handler.cc
diff --git a/chrome/utility/extensions/extensions_handler.cc b/chrome/utility/extensions/extensions_handler.cc
index 25586e9b3a2a8ca919b4e94757e2ab19337474b8..c78097123aa292db09fddfc465c42034a25ded94 100644
--- a/chrome/utility/extensions/extensions_handler.cc
+++ b/chrome/utility/extensions/extensions_handler.cc
@@ -120,11 +120,15 @@ bool ExtensionsHandler::OnMessageReceived(const IPC::Message& message) {
 void ExtensionsHandler::OnCheckMediaFile(
     int64 milliseconds_of_decoding,
     const IPC::PlatformFileForTransit& media_file) {
+#if !defined(MEDIA_DISABLE_FFMPEG)
   media::MediaFileChecker checker(
       IPC::PlatformFileForTransitToFile(media_file));
   const bool check_success = checker.Start(
       base::TimeDelta::FromMilliseconds(milliseconds_of_decoding));
   Send(new ChromeUtilityHostMsg_CheckMediaFile_Finished(check_success));
+#else
+  Send(new ChromeUtilityHostMsg_CheckMediaFile_Finished(false));

[xhwang, 2015/11/02 18:11:51]

I suppose we'll never reach here (since nobody complaints so far), maybe
NOTREACHED()? +Reilly Grant

[Julien Isorce Samsung, 2015/11/03 16:02:27]

You are right, I'll add NOTREACHED() so that it won't be silent if actually
reached.

+#endif
   ReleaseProcessIfNeeded();
 }