Move discardable memory to //components from //content

components/discardable_memory/service/BUILD.gn

 # 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")
-}
+import("//testing/test.gni")
 
-static_library("request_header") {
+component("service") {
+  output_name = "discardable_memory_service"
+
+  defines = [ "DISCARDABLE_MEMORY_IMPLEMENTATION" ]
+
   sources = [
-    "offline_page_header.cc",
-    "offline_page_header.h",
+    "discardable_shared_memory_manager.cc",
+    "discardable_shared_memory_manager.h",
   ]
 
   deps = [
     "//base",
   ]
 }
 
 source_set("unit_tests") {
   testonly = true
+
   sources = [
-    "offline_page_header_unittest.cc",
+    "discardable_shared_memory_manager_unittest.cc",
   ]
 
   deps = [
-    ":request_header",
+    ":service",
     "//base",
-    "//base/test:test_support",
     "//testing/gtest",
   ]
 }