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

media/audio/linux/audio_manager_linux.cc

Index: media/audio/linux/audio_manager_linux.cc
diff --git a/media/audio/linux/audio_manager_linux.cc b/media/audio/linux/audio_manager_linux.cc
index 53c0711d5456ec71038ab0303ddd7bb1b1f2c0db..ff6cbbd088934aa8c9fd87aef6f9db6c029f9ba3 100644
--- a/media/audio/linux/audio_manager_linux.cc
+++ b/media/audio/linux/audio_manager_linux.cc
@@ -92,14 +92,14 @@ void AudioManagerLinux::ShowAudioInputSettings() {
   CommandLine command_line(CommandLine::NO_PROGRAM);
   switch (base::nix::GetDesktopEnvironment(env.get())) {
     case base::nix::DESKTOP_ENVIRONMENT_GNOME:
-      command_line.SetProgram(FilePath("gnome-volume-control"));
+      command_line.SetProgram(base::FilePath("gnome-volume-control"));
       break;
     case base::nix::DESKTOP_ENVIRONMENT_KDE3:
     case base::nix::DESKTOP_ENVIRONMENT_KDE4:
-      command_line.SetProgram(FilePath("kmix"));
+      command_line.SetProgram(base::FilePath("kmix"));
       break;
     case base::nix::DESKTOP_ENVIRONMENT_UNITY:
-      command_line.SetProgram(FilePath("gnome-control-center"));
+      command_line.SetProgram(base::FilePath("gnome-control-center"));
       command_line.AppendArg("sound");
       command_line.AppendArg("input");
       break;