[screen-orientation] Update implementation to match recent spec changes.

Source/modules/modules.gypi

 {
   'includes': [
     '../core/core_generated.gypi',
     'modules_generated.gypi',
   ],
   'variables': {
     # Experimental hooks for embedder to provide extra IDL and source files.
     #
     # Note: this is not a supported API. If you rely on this, you will be broken
     # from time to time as the code generator changes in backward incompatible
@@ skipping 101 matching lines @@
       'push_messaging/PushEvent.idl',
       'push_messaging/PushManager.idl',
       'push_messaging/PushRegistration.idl',
       'quota/DeprecatedStorageInfo.idl',
       'quota/DeprecatedStorageQuota.idl',
       'quota/StorageErrorCallback.idl',
       'quota/StorageInfo.idl',
       'quota/StorageQuota.idl',
       'quota/StorageQuotaCallback.idl',
       'quota/StorageUsageCallback.idl',
+      'screen_orientation/ScreenOrientation.idl',
       'serviceworkers/Client.idl',
       'serviceworkers/FetchEvent.idl',
       'serviceworkers/HeaderMap.idl',
       'serviceworkers/HeaderMapForEachCallback.idl',
       'serviceworkers/Headers.idl',
       'serviceworkers/HeadersForEachCallback.idl',
       'serviceworkers/InstallEvent.idl',
       'serviceworkers/InstallPhaseEvent.idl',
       'serviceworkers/Request.idl',
       'serviceworkers/Response.idl',
@@ skipping 95 matching lines @@
       'navigatorcontentutils/NavigatorContentUtils.idl',
       'netinfo/NavigatorNetworkInformation.idl',
       'netinfo/WorkerNavigatorNetworkInformation.idl',
       'performance/SharedWorkerPerformance.idl',
       'performance/WorkerGlobalScopePerformance.idl',
       'push_messaging/NavigatorPushManager.idl',
       'push_messaging/ServiceWorkerGlobalScopePush.idl',
       'quota/NavigatorStorageQuota.idl',
       'quota/WindowQuota.idl',
       'quota/WorkerNavigatorStorageQuota.idl',
-      'screen_orientation/ScreenOrientation.idl',
+      'screen_orientation/PartialScreenOrientation.idl',
       'serviceworkers/NavigatorServiceWorker.idl',
       'speech/WindowSpeech.idl',
       'speech/WindowSpeechSynthesis.idl',
       'vibration/NavigatorVibration.idl',
       'webaudio/WindowWebAudio.idl',
       'webdatabase/WindowWebDatabase.idl',
       'webdatabase/WorkerGlobalScopeWebDatabase.idl',
       'webmidi/NavigatorWebMIDI.idl',
     ],
     # interfaces that inherit from Event
@@ skipping 391 matching lines @@
       'quota/StorageQuotaCallback.h',
       'quota/StorageQuotaCallbacksImpl.cpp',
       'quota/StorageQuotaCallbacksImpl.h',
       'quota/StorageQuotaClient.cpp',
       'quota/StorageQuotaClient.h',
       'quota/StorageUsageCallback.h',
       'quota/WorkerNavigatorStorageQuota.cpp',
       'quota/WorkerNavigatorStorageQuota.h',
       'screen_orientation/LockOrientationCallback.cpp',
       'screen_orientation/LockOrientationCallback.h',
+      'screen_orientation/PartialScreenOrientation.cpp',
+      'screen_orientation/PartialScreenOrientation.h',
       'screen_orientation/ScreenOrientation.cpp',
       'screen_orientation/ScreenOrientation.h',
       'screen_orientation/ScreenOrientationController.cpp',
       'screen_orientation/ScreenOrientationController.h',
       'serviceworkers/Client.cpp',
       'serviceworkers/Client.h',
       'serviceworkers/FetchEvent.cpp',
       'serviceworkers/FetchEvent.h',
       'serviceworkers/FetchHeaderList.cpp',
       'serviceworkers/FetchHeaderList.h',
@@ skipping 325 matching lines @@
       'indexeddb/IDBRequestTest.cpp',
       'indexeddb/IDBTransactionTest.cpp',
       'websockets/WebSocketDeflaterTest.cpp',
       'websockets/WebSocketExtensionDispatcherTest.cpp',
       'websockets/WebSocketExtensionParserTest.cpp',
       'websockets/WebSocketPerMessageDeflateTest.cpp',
       'websockets/WebSocketTest.cpp',
     ],
   },
 }