Moving mediaplayer to the chrome filebrowser. Observable behaviour should not change.

chrome/chrome_browser.gypi

Index: chrome/chrome_browser.gypi
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 5d8ceb64584e9359b1e53634c68dd8667402c2b5..85eb4d65a7451bae425ef5ae7d1962e77704d1f8 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -414,6 +414,8 @@
         'browser/chromeos/enterprise_extension_observer.h',
         'browser/chromeos/extensions/file_browser_event_router.cc',
         'browser/chromeos/extensions/file_browser_event_router.h',
+        'browser/chromeos/extensions/media_player_event_router.cc',
+        'browser/chromeos/extensions/media_player_event_router.h',
         'browser/chromeos/external_metrics.cc',
         'browser/chromeos/external_metrics.h',
         'browser/chromeos/external_protocol_dialog.cc',
@@ -621,6 +623,8 @@
         'browser/chromeos/login/wizard_screen.h',
         'browser/chromeos/low_battery_observer.cc',
         'browser/chromeos/low_battery_observer.h',
+        'browser/chromeos/media/media_player.cc',
+        'browser/chromeos/media/media_player.h',
         'browser/chromeos/metrics_cros_settings_provider.cc',
         'browser/chromeos/metrics_cros_settings_provider.h',
         'browser/chromeos/name_value_pairs_parser.cc',
@@ -960,6 +964,8 @@
         'browser/extensions/extension_management_api.h',
         'browser/extensions/extension_menu_manager.cc',
         'browser/extensions/extension_menu_manager.h',
+        'browser/extensions/extension_mediaplayer_private_api.h',
+        'browser/extensions/extension_mediaplayer_private_api.cc',
         'browser/extensions/extension_message_handler.cc',
         'browser/extensions/extension_message_handler.h',
         'browser/extensions/extension_message_service.cc',
@@ -3332,8 +3338,6 @@
         'browser/ui/webui/html_dialog_ui.h',
         'browser/ui/webui/keyboard_ui.cc',
         'browser/ui/webui/keyboard_ui.h',
-        'browser/ui/webui/mediaplayer_ui.cc',
-        'browser/ui/webui/mediaplayer_ui.h',
         'browser/ui/webui/net_internals_ui.cc',
         'browser/ui/webui/net_internals_ui.h',
         'browser/ui/webui/ntp/app_launcher_handler.cc',
@@ -3539,6 +3543,8 @@
             ['exclude', '^browser/ui/webui/options/chromeos'],
             ['exclude', 'browser/extensions/extension_file_browser_private_api.cc'],
             ['exclude', 'browser/extensions/extension_file_browser_private_api.h'],
+            ['exclude', 'browser/extensions/extension_mediaplayer_private_api.cc'],
+            ['exclude', 'browser/extensions/extension_mediaplayer_private_api.h'],
             ['exclude', 'browser/extensions/extension_tts_api_chromeos.cc'],
             ['exclude', 'browser/extensions/file_manager_util.h'],
             ['exclude', 'browser/extensions/file_manager_util.cc'],
@@ -3560,7 +3566,6 @@
             ['exclude', 'browser/ui/webui/collected_cookies_ui_delegate.h'],
             ['exclude', 'browser/ui/webui/cookies_tree_model_adapter.cc'],
             ['exclude', 'browser/ui/webui/cookies_tree_model_adapter.h'],
-            ['exclude', 'browser/ui/webui/mediaplayer_ui.cc'],
           ],
         }],
         ['chromeos==1', {