Update from https://crrev.com/316786

base/memory/discardable_memory_unittest.cc

 // Copyright (c) 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 "base/memory/discardable_memory.h"
 
 #include <algorithm>
 
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 64 matching lines @@
 
   memory->Unlock();
 }
 
 // Test delete a discardable memory while it is locked.
 TEST_P(DiscardableMemoryTest, DeleteWhileLocked) {
   const scoped_ptr<DiscardableMemory> memory(CreateLockedMemory(kSize));
   ASSERT_TRUE(memory);
 }
 
-// Test forced purging.
-TEST_P(DiscardableMemoryTest, Purge) {
-  const scoped_ptr<DiscardableMemory> memory(CreateLockedMemory(kSize));
-  ASSERT_TRUE(memory);
-  memory->Unlock();
-
-  DiscardableMemory::PurgeForTesting();
-  EXPECT_EQ(DISCARDABLE_MEMORY_LOCK_STATUS_PURGED, memory->Lock());
-}
-
 #if !defined(NDEBUG) && !defined(OS_ANDROID)
 // Death tests are not supported with Android APKs.
 TEST_P(DiscardableMemoryTest, UnlockedMemoryAccessCrashesInDebugMode) {
   const scoped_ptr<DiscardableMemory> memory(CreateLockedMemory(kSize));
   ASSERT_TRUE(memory);
   memory->Unlock();
   ASSERT_DEATH_IF_SUPPORTED(
       { *static_cast<int*>(memory->Memory()) = 0xdeadbeef; }, ".*");
 }
 #endif
@@ skipping 24 matching lines @@
   return supported_types;
 }
 
 INSTANTIATE_TEST_CASE_P(
     DiscardableMemoryTests,
     DiscardableMemoryTest,
     ::testing::ValuesIn(GetSupportedDiscardableMemoryTypes()));
 
 }  // namespace
 }  // namespace base