replace COMPILE_ASSERT with static_assert in ui/

ui/aura/window_tree_host_x11.cc

Index: ui/aura/window_tree_host_x11.cc
diff --git a/ui/aura/window_tree_host_x11.cc b/ui/aura/window_tree_host_x11.cc
index 5c9eb35852afb8c14be76a4a08894a87b8a00291..a74d0bb43bc64b57db35c68ae38957870e520b26 100644
--- a/ui/aura/window_tree_host_x11.cc
+++ b/ui/aura/window_tree_host_x11.cc
@@ -281,7 +281,8 @@ WindowTreeHostX11::WindowTreeHostX11(const gfx::Rect& bounds)
   // Likewise, the X server needs to know this window's pid so it knows which
   // program to kill if the window hangs.
   // XChangeProperty() expects "pid" to be long.
-  COMPILE_ASSERT(sizeof(long) >= sizeof(pid_t), pid_t_bigger_than_long);
+  static_assert(sizeof(long) >= sizeof(pid_t),
+                "pid_t should not be larger than long");
   long pid = getpid();
   XChangeProperty(xdisplay_,
                   xwindow_,