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

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 "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace {
+
+const size_t kSize = 1024;
+
+// Test Lock() and Unlock() functionalities.
+TEST(DiscardableMemoryTest, LockAndUnLock) {
+  const scoped_ptr<DiscardableMemory> memory(
+      DiscardableMemory::CreateLockedMemory(kSize));
+  ASSERT_TRUE(memory);
+  void* addr = memory->Memory();
+  EXPECT_NE(nullptr, addr);
+  memory->Unlock();
+}
+
+// Test delete a discardable memory while it is locked.
+TEST(DiscardableMemoryTest, DeleteWhileLocked) {
+  const scoped_ptr<DiscardableMemory> memory(
+      DiscardableMemory::CreateLockedMemory(kSize));
+  ASSERT_TRUE(memory);
+}
+
+#if !defined(NDEBUG) && !defined(OS_ANDROID)
+// Death tests are not supported with Android APKs.
+TEST(DiscardableMemoryTest, UnlockedMemoryAccessCrashesInDebugMode) {
+  const scoped_ptr<DiscardableMemory> memory(
+      DiscardableMemory::CreateLockedMemory(kSize));
+  ASSERT_TRUE(memory);
+  memory->Unlock();
+  ASSERT_DEATH_IF_SUPPORTED(
+      { *static_cast<int*>(memory->Memory()) = 0xdeadbeef; }, ".*");
+}
+#endif
+
+// Test behavior when creating enough instances that could use up a 32-bit
+// address space.
+// This is disabled under AddressSanitizer on Windows as it crashes (by design)
+// on OOM. See http://llvm.org/PR22026 for the details.
+#if !defined(ADDRESS_SANITIZER) || !defined(OS_WIN)
+TEST(DiscardableMemoryTest, AddressSpace) {
+  const size_t kLargeSize = 4 * 1024 * 1024;  // 4MiB.
+  const size_t kNumberOfInstances = 1024 + 1;  // >4GiB total.
+
+  scoped_ptr<DiscardableMemory> instances[kNumberOfInstances];
+  for (auto& memory : instances) {
+    memory = DiscardableMemory::CreateLockedMemory(kLargeSize);
+    ASSERT_TRUE(memory);
+    void* addr = memory->Memory();
+    EXPECT_NE(nullptr, addr);
+    memory->Unlock();
+  }
+}
+#endif
+
+}  // namespace
+}  // namespace base