Move all components/offline_pages/ files into component/offline_pages/core

components/offline_pages/request_header/BUILD.gn

Index: components/offline_pages/request_header/BUILD.gn
diff --git a/components/offline_pages/request_header/BUILD.gn b/components/offline_pages/request_header/BUILD.gn
deleted file mode 100644
index 711623cc3481ce69aee7d0bf41b1812ca406ff85..0000000000000000000000000000000000000000
--- a/components/offline_pages/request_header/BUILD.gn
+++ /dev/null
@@ -1,32 +0,0 @@
-# Copyright 2016 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.
-
-if (is_android) {
-  import("//build/config/android/rules.gni")
-}
-
-static_library("request_header") {
-  sources = [
-    "offline_page_header.cc",
-    "offline_page_header.h",
-  ]
-
-  deps = [
-    "//base",
-  ]
-}
-
-source_set("unit_tests") {
-  testonly = true
-  sources = [
-    "offline_page_header_unittest.cc",
-  ]
-
-  deps = [
-    ":request_header",
-    "//base",
-    "//base/test:test_support",
-    "//testing/gtest",
-  ]
-}