Clarify resolution change behaviors of video capture devices

content/common/media/video_capture_messages.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/memory/shared_memory.h"
 #include "content/common/content_export.h"
 #include "content/common/media/video_capture.h"
 #include "content/public/common/common_param_traits.h"
 #include "gpu/command_buffer/common/mailbox_holder.h"
 #include "ipc/ipc_message_macros.h"
 #include "media/video/capture/video_capture_types.h"
 
 #undef IPC_MESSAGE_EXPORT
 #define IPC_MESSAGE_EXPORT CONTENT_EXPORT
 #define IPC_MESSAGE_START VideoCaptureMsgStart
 
 IPC_ENUM_TRAITS_MAX_VALUE(content::VideoCaptureState,
                           content::VIDEO_CAPTURE_STATE_LAST)
 
+IPC_ENUM_TRAITS_MAX_VALUE(media::ResolutionChangePolicy,
+                          media::RESOLUTION_POLICY_LAST)
+
 IPC_STRUCT_TRAITS_BEGIN(media::VideoCaptureParams)
   IPC_STRUCT_TRAITS_MEMBER(requested_format)
-  IPC_STRUCT_TRAITS_MEMBER(allow_resolution_change)
+  IPC_STRUCT_TRAITS_MEMBER(resolution_change_policy)
 IPC_STRUCT_TRAITS_END()
 
 // TODO(nick): device_id in these messages is basically just a route_id. We
 // should shift to IPC_MESSAGE_ROUTED and use MessageRouter in the filter impls.
 
 // Notify the renderer process about the state update such as
 // Start/Pause/Stop.
 IPC_MESSAGE_CONTROL2(VideoCaptureMsg_StateChanged,
                      int /* device id */,
                      content::VideoCaptureState /* new state */)
@@ skipping 64 matching lines @@
 
 // Get the formats supported by a device referenced by |capture_session_id|.
 IPC_MESSAGE_CONTROL2(VideoCaptureHostMsg_GetDeviceSupportedFormats,
                      int /* device_id */,
                      media::VideoCaptureSessionId /* session_id */)
 
 // Get the format(s) in use by a device referenced by |capture_session_id|.
 IPC_MESSAGE_CONTROL2(VideoCaptureHostMsg_GetDeviceFormatsInUse,
                      int /* device_id */,
                      media::VideoCaptureSessionId /* session_id */)