Remove unused mojo binding.h includes in //ui/ozone

This CL cleans up unnecessary mojo/public/cpp/bindings/binding.h
includes in //ui/ozone.

Bug: 955171
Change-Id: I55221d9c2b72d3223940292e96c4f4d16f7b832c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1978479Reviewed-by: Maksim Sisov <msisov@igalia.com>
Reviewed-by: Ken Rockot <rockot@google.com>
Reviewed-by: Michael Spang <spang@chromium.org>
Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
Commit-Queue: Gyuyoung Kim <gyuyoung@igalia.com>
Cr-Commit-Position: refs/heads/master@{#728750}

ui/ozone/platform/wayland/host/wayland_input_method_context_unittest.cc

@@ -6,7 +6,6 @@
 #include <wayland-server.h>
 #include <memory>
 
-#include "mojo/public/cpp/bindings/binding.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/base/ime/linux/linux_input_method_context.h"

ui/ozone/public/gpu_platform_support_host.h

@@ -12,7 +12,7 @@
 #include "base/single_thread_task_runner.h"
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_sender.h"
-#include "mojo/public/cpp/bindings/binding.h"
+#include "mojo/public/cpp/system/message_pipe.h"
 
 namespace ui {