Revert "base: Implement browser process support for discardable memory."

chrome/test/base/chrome_unit_test_suite.cc

 // Copyright 2013 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.
 
 #include "chrome/test/base/chrome_unit_test_suite.h"
 
 #include "base/path_service.h"
 #include "base/process/process_handle.h"
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/chrome_content_browser_client.h"
@@ skipping 92 matching lines @@
   listeners.Append(new ChromeUnitTestSuiteInitializer);
 
   InitializeProviders();
   RegisterInProcessThreads();
 
   ChromeTestSuite::Initialize();
 
   // This needs to run after ChromeTestSuite::Initialize which calls content's
   // intialization which calls base's which initializes ICU.
   InitializeResourceBundle();
-
-  base::DiscardableMemoryShmemAllocator::SetInstance(
-      &discardable_memory_allocator_);
 }
 
 void ChromeUnitTestSuite::Shutdown() {
   ResourceBundle::CleanupSharedInstance();
   ChromeTestSuite::Shutdown();
 }
 
 void ChromeUnitTestSuite::InitializeProviders() {
   {
     ChromeContentClient content_client;
@@ skipping 40 matching lines @@
 #if defined(OS_MACOSX) && !defined(OS_IOS)
   PathService::Get(base::DIR_MODULE, &resources_pack_path);
   resources_pack_path =
       resources_pack_path.Append(FILE_PATH_LITERAL("resources.pak"));
 #else
   PathService::Get(chrome::FILE_RESOURCES_PACK, &resources_pack_path);
 #endif
   ResourceBundle::GetSharedInstance().AddDataPackFromPath(
       resources_pack_path, ui::SCALE_FACTOR_NONE);
 }