Refactor "track options" to be a dictionary.

third_party/WebKit/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 438 matching lines @@
       'filesystem/FileSystemFlags.idl',
       'gamepad/GamepadEventInit.idl',
       'geofencing/CircularGeofencingRegionInit.idl',
       'geolocation/PositionOptions.idl',
       'indexeddb/IDBIndexParameters.idl',
       'indexeddb/IDBObjectStoreParameters.idl',
       'indexeddb/IDBVersionChangeEventInit.idl',
       'mediarecorder/BlobEventInit.idl',
       'mediastream/MediaStreamConstraints.idl',
       'mediastream/MediaStreamEventInit.idl',
+      'mediastream/MediaTrackConstraintSet.idl',
       'mediastream/RTCDTMFToneChangeEventInit.idl',
       'mediastream/RTCIceCandidateInit.idl',
       'mediastream/RTCSessionDescriptionInit.idl',
       'navigatorconnect/ServicePortConnectEventInit.idl',
       'navigatorconnect/ServicePortConnectOptions.idl',
       'navigatorconnect/ServicePortConnectResponse.idl',
       'navigatorconnect/ServicePortMatchOptions.idl',
       'notifications/GetNotificationOptions.idl',
       'notifications/NotificationAction.idl',
       'notifications/NotificationEventInit.idl',
@@ skipping 95 matching lines @@
       '<(blink_modules_output_dir)/indexeddb/IDBObjectStoreParameters.cpp',
       '<(blink_modules_output_dir)/indexeddb/IDBObjectStoreParameters.h',
       '<(blink_modules_output_dir)/indexeddb/IDBVersionChangeEventInit.cpp',
       '<(blink_modules_output_dir)/indexeddb/IDBVersionChangeEventInit.h',
       '<(blink_modules_output_dir)/mediarecorder/BlobEventInit.cpp',
       '<(blink_modules_output_dir)/mediarecorder/BlobEventInit.h',
       '<(blink_modules_output_dir)/mediastream/MediaStreamConstraints.cpp',
       '<(blink_modules_output_dir)/mediastream/MediaStreamConstraints.h',
       '<(blink_modules_output_dir)/mediastream/MediaStreamEventInit.cpp',
       '<(blink_modules_output_dir)/mediastream/MediaStreamEventInit.h',
+      '<(blink_modules_output_dir)/mediastream/MediaTrackConstraintSet.cpp',
+      '<(blink_modules_output_dir)/mediastream/MediaTrackConstraintSet.h',
       '<(blink_modules_output_dir)/mediastream/RTCDTMFToneChangeEventInit.cpp',
       '<(blink_modules_output_dir)/mediastream/RTCDTMFToneChangeEventInit.h',
       '<(blink_modules_output_dir)/mediastream/RTCIceCandidateInit.cpp',
       '<(blink_modules_output_dir)/mediastream/RTCIceCandidateInit.h',
       '<(blink_modules_output_dir)/mediastream/RTCSessionDescriptionInit.cpp',
       '<(blink_modules_output_dir)/mediastream/RTCSessionDescriptionInit.h',
       '<(blink_modules_output_dir)/navigatorconnect/ServicePortConnectEventInit.cpp',
       '<(blink_modules_output_dir)/navigatorconnect/ServicePortConnectEventInit.h',
       '<(blink_modules_output_dir)/navigatorconnect/ServicePortConnectOptions.cpp',
       '<(blink_modules_output_dir)/navigatorconnect/ServicePortConnectOptions.h',
@@ skipping 1245 matching lines @@
       'webaudio/AudioBasicProcessorHandlerTest.cpp',
       'webaudio/ConvolverNodeTest.cpp',
       'webaudio/DynamicsCompressorNodeTest.cpp',
       'webaudio/ScriptProcessorNodeTest.cpp',
       'webaudio/StereoPannerNodeTest.cpp',
       'websockets/DOMWebSocketTest.cpp',
       'websockets/DocumentWebSocketChannelTest.cpp',
     ],
   },
 }