Fix gpu_video_decode_accelerator include order by renaming enum with X11 name collision

media/gpu/ipc/service/gpu_video_decode_accelerator.cc

Index: media/gpu/ipc/service/gpu_video_decode_accelerator.cc
diff --git a/media/gpu/ipc/service/gpu_video_decode_accelerator.cc b/media/gpu/ipc/service/gpu_video_decode_accelerator.cc
index 6e6ba3155a91627f58e84cbba567dd7fac831dea..18a17de2725e456f53a3ba4c121cd2632c177619 100644
--- a/media/gpu/ipc/service/gpu_video_decode_accelerator.cc
+++ b/media/gpu/ipc/service/gpu_video_decode_accelerator.cc
@@ -2,15 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// TODO(markdittmer): This shouldn't be necessary.
-// Ensure that X11 headers don't poison environment before macro headers are
-// loaded.
-//
-// In particular, X11/Xlib.h defines "Status", which is the name of an enum
-// defined in "base/tracked_objects.h", which is eventually required by
-// "ipc/ipc_message_macros.h".
-#include "ipc/ipc_message_macros.h"

[dcheng, 2016/05/06 19:24:00]

I'm not sure which header is doing it, but that header probably shouldn't be
including X11. We try to remove X11 #includes from public headers as much as
possible, to prevent this very problem.

[piman, 2016/05/06 19:46:47]

Agreed - do we know what includes Xlib.h here?

[Mark Dittmer, 2016/05/09 15:12:41]

The relevant preprocessor trace is as follows:

# 19 "../../media/gpu/ipc/service/gpu_video_decode_accelerator.h" 2
# 22 "../../gpu/command_buffer/service/texture_manager.h" 2
# 14 "../../gpu/command_buffer/service/gl_utils.h"
# 22 "../../ui/gl/gl_bindings.h" 2
# 39 "../../third_party/khronos/EGL/egl.h"
# 106 "../../third_party/khronos/EGL/eglplatform.h"
# 1 "/usr/include/X11/Xlib.h" 1 3 4

This shows up on GYP chromeos builds (e.g., build [1] on issue [2]).

[1]
https://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium...
[2] https://codereview.chromium.org/1958903004

-
 #include "media/gpu/ipc/service/gpu_video_decode_accelerator.h"
 
 #include <memory>
@@ -28,6 +19,7 @@
 #include "gpu/command_buffer/service/gpu_preferences.h"
 #include "gpu/ipc/service/gpu_channel.h"
 #include "gpu/ipc/service/gpu_channel_manager.h"
+#include "ipc/ipc_message_macros.h"
 #include "ipc/ipc_message_utils.h"
 #include "ipc/message_filter.h"
 #include "media/base/limits.h"