diff -up chromium-40.0.2214.91/media/base/media_posix.cc.0004 chromium-40.0.2214.91/media/base/media_posix.cc
--- chromium-40.0.2214.91/media/base/media_posix.cc.0004	2015-01-21 21:05:43.000000000 +0100
+++ chromium-40.0.2214.91/media/base/media_posix.cc	2015-01-21 23:06:05.682707382 +0100
@@ -10,12 +10,15 @@
 #include "base/logging.h"
 #include "base/strings/stringize_macros.h"
 #include "media/ffmpeg/ffmpeg_common.h"
+
+#if !defined(USE_SYSTEM_FFMPEG)
 #include "third_party/ffmpeg/ffmpeg_stubs.h"
 
 using third_party_ffmpeg::kNumStubModules;
 using third_party_ffmpeg::kModuleFfmpegsumo;
 using third_party_ffmpeg::InitializeStubs;
 using third_party_ffmpeg::StubPathMap;
+#endif  // !defined(USE_SYSTEM_FFMPEG)
 
 namespace media {
 namespace internal {
@@ -45,6 +48,11 @@ static const base::FilePath::CharType kS
 #endif
 
 bool InitializeMediaLibraryInternal(const base::FilePath& module_dir) {
+#if defined(USE_SYSTEM_FFMPEG)
+  // No initialization is necessary when using system ffmpeg,
+  // we just link directly with system ffmpeg libraries.
+  return true;
+#else
   StubPathMap paths;
 
   // First try to initialize with Chrome's sumo library.
@@ -60,6 +68,7 @@ bool InitializeMediaLibraryInternal(cons
       FILE_PATH_LITERAL(DSO_NAME("avformat", AVFORMAT_VERSION))).value());
 
   return InitializeStubs(paths);
+#endif  // !defined(USE_SYSTEM_FFMPEG)
 }
 
 }  // namespace internal