Remove screen_orientation_messages.h.

This CL is a follow-up of https://codereview.chromium.org/2745443002.

blink::WebScreenOrientationLockType traits is defined in
screen_orientation_messages.h but has only one user: manifest_manager_messages.h,
so we just move it into manifest_manager_messages.h, thus
screen_orientation_messages.h becomes empty and we can remove it completely.

BUG=678545

Review-Url: https://codereview.chromium.org/2749863004
Cr-Commit-Position: refs/heads/master@{#457344}

content/common/BUILD.gn

@@ -306,7 +306,6 @@ source_set("common") {
     "sandbox_win.cc",
     "sandbox_win.h",
     "savable_subframe.h",
-    "screen_orientation_messages.h",
     "send_zygote_child_ping_linux.cc",
     "service_manager/embedded_service_runner.cc",
     "service_manager/embedded_service_runner.h",

content/common/content_message_generator.h

@@ -37,7 +37,6 @@
 #include "content/common/quota_messages.h"
 #include "content/common/render_process_messages.h"
 #include "content/common/resource_messages.h"
-#include "content/common/screen_orientation_messages.h"
 #include "content/common/service_worker/embedded_worker_messages.h"
 #include "content/common/service_worker/service_worker_messages.h"
 #include "content/common/speech_recognition_messages.h"

content/common/manifest_manager_messages.h

@@ -8,12 +8,16 @@
 #include "content/common/content_export.h"
 #include "content/public/common/manifest.h"
 #include "ipc/ipc_message_macros.h"
+#include "third_party/WebKit/public/platform/modules/screen_orientation/WebScreenOrientationLockType.h"
 
 #undef IPC_MESSAGE_EXPORT
 #define IPC_MESSAGE_EXPORT CONTENT_EXPORT
 
 #define IPC_MESSAGE_START ManifestManagerMsgStart
 
+IPC_ENUM_TRAITS_MIN_MAX_VALUE(blink::WebScreenOrientationLockType,
+                              blink::WebScreenOrientationLockDefault,
+                              blink::WebScreenOrientationLockNatural)
 IPC_ENUM_TRAITS_MAX_VALUE(
     content::Manifest::Icon::IconPurpose,
     content::Manifest::Icon::IconPurpose::ICON_PURPOSE_LAST)

content/common/screen_orientation_messages.h

-// Copyright 2014 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.
-
-// IPC messages for screen orientation.
-// Multiply-included message file, hence no include guard.
-
-#include "content/common/content_export.h"
-#include "ipc/ipc_message_macros.h"
-#include "third_party/WebKit/public/platform/modules/screen_orientation/WebLockOrientationError.h"
-#include "third_party/WebKit/public/platform/modules/screen_orientation/WebScreenOrientationLockType.h"
-
-#undef IPC_MESSAGE_EXPORT
-#define IPC_MESSAGE_EXPORT CONTENT_EXPORT
-
-// Only used by content/common/manifest_manager_messages.h.
-IPC_ENUM_TRAITS_MIN_MAX_VALUE(blink::WebScreenOrientationLockType,
-                              blink::WebScreenOrientationLockDefault,
-                              blink::WebScreenOrientationLockNatural)