Revert 96974 - Remove mock_ffmpeg and update media unittests.

media/base/media_posix.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/base/media.h"
 
 #include <string>
 
 #include <dlfcn.h>
 
@@ skipping 74 matching lines @@
 
     // Add the more specific FFmpeg library name.
     FilePath path = module_dir.Append(GetDSOName(module));
     paths[module].push_back(path.value());
   }
 
   g_media_library_is_initialized = tp_ffmpeg::InitializeStubs(paths);
   return g_media_library_is_initialized;
 }
 
-void InitializeMediaLibraryForTesting() {
-  FilePath file_path;
-  CHECK(PathService::Get(base::DIR_EXE, &file_path));
-  CHECK(InitializeMediaLibrary(file_path));
-}
-
 bool IsMediaLibraryInitialized() {
   return g_media_library_is_initialized;
 }
 
 #if defined(OS_LINUX)
 namespace tp_openmax = third_party_openmax;
 bool InitializeOpenMaxLibrary(const FilePath& module_dir) {
   // TODO(ajwong): We need error resolution.
   tp_openmax::StubPathMap paths;
   for (int i = 0; i < static_cast<int>(tp_openmax::kNumStubModules); ++i) {
@@ skipping 11 matching lines @@
   return result;
 }
 #else
 bool InitializeOpenMaxLibrary(const FilePath& module_dir) {
   NOTIMPLEMENTED() << "OpenMAX is only used in Linux.";
   return false;
 }
 #endif
 
 }  // namespace media