Replace FilePath with base::FilePath in some more top level directories.

media/ffmpeg/ffmpeg_unittest.cc

Index: media/ffmpeg/ffmpeg_unittest.cc
diff --git a/media/ffmpeg/ffmpeg_unittest.cc b/media/ffmpeg/ffmpeg_unittest.cc
index 4de80cef9b2048698b8cbeaf73910d59bc0ea884..f1653c4a9cff62018795c0aab54041ee038e27da 100644
--- a/media/ffmpeg/ffmpeg_unittest.cc
+++ b/media/ffmpeg/ffmpeg_unittest.cc
@@ -106,7 +106,7 @@ class FFmpegTest : public testing::TestWithParam<const char*> {
   }
 
   void OpenFile(const std::string& name) {
-    FilePath path;
+    base::FilePath path;
     PathService::Get(base::DIR_SOURCE_ROOT, &path);
     path = path.AppendASCII("media")
         .AppendASCII("test")
@@ -369,7 +369,7 @@ class FFmpegTest : public testing::TestWithParam<const char*> {
       return;
     }
 
-    FilePath path;
+    base::FilePath path;
     PathService::Get(base::DIR_MODULE, &path);
     EXPECT_TRUE(InitializeMediaLibrary(path))
         << "Could not initialize media library.";