Move the serial API to extensions/.

extensions/extensions.gyp

Index: extensions/extensions.gyp
diff --git a/extensions/extensions.gyp b/extensions/extensions.gyp
index 61288863158f7c4b2897daf376f7dc5d373778a0..b0cb673dcb9b342f304799ae6f08ac8b4c660b90 100644
--- a/extensions/extensions.gyp
+++ b/extensions/extensions.gyp
@@ -234,6 +234,7 @@
         '../components/components.gyp:pref_registry',
         '../components/components.gyp:usb_service',
         '../content/content.gyp:content_browser',
+        '../device/serial/serial.gyp:device_serial',
         '../skia/skia.gyp:skia',
         '../third_party/leveldatabase/leveldatabase.gyp:leveldatabase',
         'common/api/api.gyp:extensions_api',
@@ -274,6 +275,12 @@
         'browser/api/runtime/runtime_api.h',
         'browser/api/runtime/runtime_api_delegate.cc',
         'browser/api/runtime/runtime_api_delegate.h',
+        'browser/api/serial/serial_api.cc',
+        'browser/api/serial/serial_api.h',
+        'browser/api/serial/serial_connection.cc',
+        'browser/api/serial/serial_connection.h',
+        'browser/api/serial/serial_event_dispatcher.cc',
+        'browser/api/serial/serial_event_dispatcher.h',
         'browser/api/socket/socket.cc',
         'browser/api/socket/socket.h',
         'browser/api/socket/socket_api.cc',
@@ -464,6 +471,7 @@
           ],
           'dependencies!': [
             '../components/components.gyp:usb_service',
+            '../device/serial/serial.gyp:device_serial',
           ],
         }],
       ],