Make MediaPlayerEventRouter a PKS to decouple it from ExtensionService

chrome/browser/ui/ash/chrome_shell_delegate.cc

Index: chrome/browser/ui/ash/chrome_shell_delegate.cc
diff --git a/chrome/browser/ui/ash/chrome_shell_delegate.cc b/chrome/browser/ui/ash/chrome_shell_delegate.cc
index f93747d540e9d1638db63379cbb5839145c9eea1..90e1dc96e9b8e79b0faa165f9c1892d63de10d7b 100644
--- a/chrome/browser/ui/ash/chrome_shell_delegate.cc
+++ b/chrome/browser/ui/ash/chrome_shell_delegate.cc
@@ -50,7 +50,6 @@
 #include "base/chromeos/chromeos_version.h"
 #include "chrome/browser/chromeos/accessibility/accessibility_util.h"
 #include "chrome/browser/chromeos/background/ash_user_wallpaper_delegate.h"
-#include "chrome/browser/chromeos/extensions/media_player_event_router.h"
 #include "chrome/browser/chromeos/input_method/input_method_configuration.h"
 #include "chrome/browser/chromeos/input_method/input_method_manager.h"
 #include "chrome/browser/chromeos/login/user_manager.h"
@@ -63,6 +62,11 @@
 #include "chromeos/dbus/session_manager_client.h"
 #endif
 
+#if defined(OS_CHROMEOS) && defined(FILE_MANAGER_EXTENSION)
+#include "chrome/browser/chromeos/extensions/media_player_api.h"
+#include "chrome/browser/chromeos/extensions/media_player_event_router.h"
+#endif
+
 namespace {
 
 // Returns the browser that should handle accelerators.
@@ -491,20 +495,23 @@ void ChromeShellDelegate::RecordUserMetricsAction(
 }
 
 void ChromeShellDelegate::HandleMediaNextTrack() {
-#if defined(OS_CHROMEOS)
-  ExtensionMediaPlayerEventRouter::GetInstance()->NotifyNextTrack();
+#if defined(OS_CHROMEOS) && defined(FILE_MANAGER_EXTENSION)
+  extensions::MediaPlayerAPI::Get(GetTargetBrowser()->profile())->
+      media_player_event_router()->NotifyNextTrack();
 #endif
 }
 
 void ChromeShellDelegate::HandleMediaPlayPause() {
-#if defined(OS_CHROMEOS)
-  ExtensionMediaPlayerEventRouter::GetInstance()->NotifyTogglePlayState();
+#if defined(OS_CHROMEOS) && defined(FILE_MANAGER_EXTENSION)
+  extensions::MediaPlayerAPI::Get(GetTargetBrowser()->profile())->
+      media_player_event_router()->NotifyTogglePlayState();
 #endif
 }
 
 void ChromeShellDelegate::HandleMediaPrevTrack() {
-#if defined(OS_CHROMEOS)
-  ExtensionMediaPlayerEventRouter::GetInstance()->NotifyPrevTrack();
+#if defined(OS_CHROMEOS) && defined(FILE_MANAGER_EXTENSION)
+  extensions::MediaPlayerAPI::Get(GetTargetBrowser()->profile())->
+      media_player_event_router()->NotifyPrevTrack();
 #endif
 }