media/capabilities/in_memory_video_decode_stats_db_unittest.cc - chromium/src - Git at Google

 // Copyright 2018 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 <memory>

 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/test/gtest_util.h"
 #include "base/test/scoped_task_environment.h"
 #include "media/capabilities/in_memory_video_decode_stats_db_impl.h"
 #include "media/capabilities/video_decode_stats_db_impl.h"
 #include "media/capabilities/video_decode_stats_db_provider.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"

 using testing::_;
 using testing::Eq;
 using testing::Pointee;
 using testing::IsNull;

 namespace media {

 static VideoDecodeStatsDB::VideoDescKey kTestKey() {
   return VideoDecodeStatsDB::VideoDescKey::MakeBucketedKey(
       VP9PROFILE_PROFILE3, gfx::Size(1024, 768), 60, "com.widevine.alpha",
       false);
 }

 static VideoDecodeStatsDB::DecodeStatsEntry kEmtpyEntry() {
   return VideoDecodeStatsDB::DecodeStatsEntry(0, 0, 0);
 }

 class MockSeedDB : public VideoDecodeStatsDB {
  public:
   MockSeedDB() = default;
   ~MockSeedDB() override = default;

   MOCK_METHOD1(Initialize, void(InitializeCB init_cb));
   MOCK_METHOD3(AppendDecodeStats,
                void(const VideoDescKey& key,
                     const DecodeStatsEntry& entry,
                     AppendDecodeStatsCB append_done_cb));
   MOCK_METHOD2(GetDecodeStats,
                void(const VideoDescKey& key, GetDecodeStatsCB get_stats_cb));
   MOCK_METHOD1(ClearStats, void(base::OnceClosure destroy_done_cb));
 };

 class MockDBProvider : public VideoDecodeStatsDBProvider {
  public:
   MockDBProvider() = default;
   ~MockDBProvider() override = default;

   MOCK_METHOD1(GetVideoDecodeStatsDB, void(GetCB get_db_b));
 };

 template <bool WithSeedDB>
 class InMemoryDBTestBase : public testing::Test {
  public:
   InMemoryDBTestBase()
       : seed_db_(WithSeedDB ? new MockSeedDB() : nullptr),
         db_provider_(WithSeedDB ? new MockDBProvider() : nullptr),
         in_memory_db_(new InMemoryVideoDecodeStatsDBImpl(db_provider_.get())) {
     // Setup MockDBProvider to provide the seed DB. No need to initialize the
     // DB here since it too is a Mock.
     if (db_provider_) {
       using GetCB = VideoDecodeStatsDBProvider::GetCB;
       ON_CALL(*db_provider_, GetVideoDecodeStatsDB(_))
           .WillByDefault([&](GetCB cb) { std::move(cb).Run(seed_db_.get()); });
     }

     // The InMemoryDB should NEVER modify the seed DB.
     if (seed_db_) {
       EXPECT_CALL(*seed_db_, AppendDecodeStats(_, _, _)).Times(0);
       EXPECT_CALL(*seed_db_, ClearStats(_)).Times(0);
     }
   }

   void InitializeEmptyDB() {
     if (seed_db_)
       EXPECT_CALL(*db_provider_, GetVideoDecodeStatsDB(_));

     EXPECT_CALL(*this, InitializeCB(true));

     in_memory_db_->Initialize(base::BindOnce(&InMemoryDBTestBase::InitializeCB,
                                              base::Unretained(this)));
     scoped_task_environment_.RunUntilIdle();
   }

   MOCK_METHOD1(InitializeCB, void(bool success));
   MOCK_METHOD1(AppendDecodeStatsCB, void(bool success));
   MOCK_METHOD2(
       GetDecodeStatsCB,
       void(bool success,
            std::unique_ptr<VideoDecodeStatsDB::DecodeStatsEntry> entry));
   MOCK_METHOD0(ClearStatsCB, void());

  protected:
   using VideoDescKey = media::VideoDecodeStatsDB::VideoDescKey;
   using DecodeStatsEntry = media::VideoDecodeStatsDB::DecodeStatsEntry;

   base::test::ScopedTaskEnvironment scoped_task_environment_;
   std::unique_ptr<MockSeedDB> seed_db_;
   std::unique_ptr<MockDBProvider> db_provider_;
   std::unique_ptr<InMemoryVideoDecodeStatsDBImpl> in_memory_db_;
 };

 // Specialization for tests that have/lack a seed DB. Some tests only make sense
 // with seed DB, so we separate them.
 class SeededInMemoryDBTest : public InMemoryDBTestBase<true> {};
 class SeedlessInMemoryDBTest : public InMemoryDBTestBase<false> {};

 TEST_F(SeedlessInMemoryDBTest, ReadExpectingEmpty) {
   InitializeEmptyDB();

   // Database is empty, seed DB is empty => expect empty stats entry.
   EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(kEmtpyEntry()))));

   in_memory_db_->GetDecodeStats(
       kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
                                  base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
 }

 TEST_F(SeededInMemoryDBTest, ReadExpectingEmpty) {
   InitializeEmptyDB();

   // Make seed DB return null (empty) for this request.
   EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _))
       .WillOnce([](const auto& key, auto get_cb) {
         std::move(get_cb).Run(true, nullptr);
       });

   // Database is empty, seed DB is empty => expect empty stats entry.
   EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(kEmtpyEntry()))));

   in_memory_db_->GetDecodeStats(
       kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
                                  base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
 }

 TEST_F(SeededInMemoryDBTest, ReadExpectingSeedData) {
   InitializeEmptyDB();

   // Setup seed DB to return an entry for the test key.
   DecodeStatsEntry seed_entry(1000, 2, 10);

   EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _))
       .WillOnce([&](const auto& key, auto get_cb) {
         std::move(get_cb).Run(true,
                               std::make_unique<DecodeStatsEntry>(seed_entry));
       });

   // Seed DB has a an entry for the test key. Expect it!
   EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(seed_entry))));

   in_memory_db_->GetDecodeStats(
       kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
                                  base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
   ::testing::Mock::VerifyAndClear(this);

   // Verify a second GetDecodeStats() call with the same key does not trigger a
   // second call to the seed DB (we cache it).
   EXPECT_CALL(*seed_db_, GetDecodeStats(_, _)).Times(0);
   EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(seed_entry))));
   in_memory_db_->GetDecodeStats(
       kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
                                  base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
 }

 TEST_F(SeededInMemoryDBTest, AppendReadAndClear) {
   const DecodeStatsEntry seed_entry(1000, 2, 10);
   const DecodeStatsEntry double_seed_entry(2000, 4, 20);
   const DecodeStatsEntry triple_seed_entry(3000, 6, 30);

   InitializeEmptyDB();

   // Setup seed DB to always return an entry for the test key.
   ON_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _))
       .WillByDefault([&](const auto& key, auto get_cb) {
         std::move(get_cb).Run(true,
                               std::make_unique<DecodeStatsEntry>(seed_entry));
       });

   // First append should trigger a request for the same key from the seed DB.
   // Simulate a successful read providing seed_entry for that key.
   EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _));

   // Append the same seed entry, doubling the stats for this key.
   EXPECT_CALL(*this, AppendDecodeStatsCB(true));
   in_memory_db_->AppendDecodeStats(
       kTestKey(), seed_entry,
       base::BindOnce(&InMemoryDBTestBase::AppendDecodeStatsCB,
                      base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
   ::testing::Mock::VerifyAndClear(this);

   // Seed DB should not be queried again for this key.
   EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _)).Times(0);

   // Now verify that the stats were doubled by the append above.
   EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(double_seed_entry))));
   in_memory_db_->GetDecodeStats(
       kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
                                  base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
   ::testing::Mock::VerifyAndClear(this);

   // Append the same seed entry again to triple the stats. Additional appends
   // should not trigger queries the seed DB for this key.
   EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _)).Times(0);
   in_memory_db_->AppendDecodeStats(
       kTestKey(), seed_entry,
       base::BindOnce(&InMemoryDBTestBase::AppendDecodeStatsCB,
                      base::Unretained(this)));

   // Verify we have 3x the stats.
   EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(triple_seed_entry))));
   in_memory_db_->GetDecodeStats(
       kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
                                  base::Unretained(this)));

   // Now destroy the in-memory stats...
   EXPECT_CALL(*this, ClearStatsCB());
   in_memory_db_->ClearStats(base::BindOnce(&InMemoryDBTestBase::ClearStatsCB,
                                            base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
   ::testing::Mock::VerifyAndClear(this);

   // With in-memory stats now gone, GetDecodeStats(kTestKey()) should again
   // trigger a call to the seed DB and return the un-doubled seed stats.
   EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _));
   EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(seed_entry))));
   in_memory_db_->GetDecodeStats(
       kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
                                  base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
 }

 TEST_F(SeedlessInMemoryDBTest, AppendReadAndClear) {
   const DecodeStatsEntry entry(50, 1, 5);
   const DecodeStatsEntry double_entry(100, 2, 10);

   InitializeEmptyDB();

   // Expect successful append to the empty seedless DB.
   EXPECT_CALL(*this, AppendDecodeStatsCB(true));
   in_memory_db_->AppendDecodeStats(
       kTestKey(), entry,
       base::BindOnce(&InMemoryDBTestBase::AppendDecodeStatsCB,
                      base::Unretained(this)));

   // Verify stats can be read back.
   EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(entry))));
   in_memory_db_->GetDecodeStats(
       kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
                                  base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
   ::testing::Mock::VerifyAndClear(this);

   // Append same stats again to test summation.
   EXPECT_CALL(*this, AppendDecodeStatsCB(true));
   in_memory_db_->AppendDecodeStats(
       kTestKey(), entry,
       base::BindOnce(&InMemoryDBTestBase::AppendDecodeStatsCB,
                      base::Unretained(this)));

   // Verify doubled stats can be read back.
   EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(double_entry))));
   in_memory_db_->GetDecodeStats(
       kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
                                  base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
   ::testing::Mock::VerifyAndClear(this);

   // Now destroy the in-memory stats...
   EXPECT_CALL(*this, ClearStatsCB());
   in_memory_db_->ClearStats(base::BindOnce(&InMemoryDBTestBase::ClearStatsCB,
                                            base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
   ::testing::Mock::VerifyAndClear(this);

   // Verify DB now empty for this key.
   EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(kEmtpyEntry()))));
   in_memory_db_->GetDecodeStats(
       kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
                                  base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
 }

 TEST_F(SeededInMemoryDBTest, ProvidedNullSeedDB) {
   // DB provider may provide a null seed DB if it encounters some error.
   EXPECT_CALL(*db_provider_, GetVideoDecodeStatsDB(_))
       .WillOnce([](auto get_db_cb) { std::move(get_db_cb).Run(nullptr); });

   // Failing to obtain the seed DB is not a show stopper. The in-memory DB
   // should simply carry on in a seedless fashion.
   EXPECT_CALL(*this, InitializeCB(true));
   in_memory_db_->Initialize(base::BindOnce(&InMemoryDBTestBase::InitializeCB,
                                            base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
   ::testing::Mock::VerifyAndClear(this);

   // Writes still succeed.
   EXPECT_CALL(*this, AppendDecodeStatsCB(true));
   const DecodeStatsEntry entry(50, 1, 5);
   in_memory_db_->AppendDecodeStats(
       kTestKey(), entry,
       base::BindOnce(&InMemoryDBTestBase::AppendDecodeStatsCB,
                      base::Unretained(this)));

   // Reads should still succeed.
   EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(entry))));
   in_memory_db_->GetDecodeStats(
       kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
                                  base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
 }

 TEST_F(SeededInMemoryDBTest, SeedReadFailureOnGettingStats) {
   // Everything seems fine at initialization...
   InitializeEmptyDB();

   // But seed DB will repeatedly fail to provide stats.
   ON_CALL(*seed_db_, GetDecodeStats(_, _))
       .WillByDefault([](const auto& key, auto get_cb) {
         std::move(get_cb).Run(false, nullptr);
       });

   // Reading the in-memory will still try to read the seed DB, and the read
   // callback will simply report that the DB is empty for this key.
   EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _));
   EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(kEmtpyEntry()))));
   in_memory_db_->GetDecodeStats(
       kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
                                  base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
 }

 TEST_F(SeededInMemoryDBTest, SeedReadFailureOnAppendingingStats) {
   // Everything seems fine at initialization...
   InitializeEmptyDB();

   // But seed DB will repeatedly fail to provide stats.
   ON_CALL(*seed_db_, GetDecodeStats(_, _))
       .WillByDefault([](const auto& key, auto get_cb) {
         std::move(get_cb).Run(false, nullptr);
       });

   // Appending to the in-memory will still try to read the seed DB, and the
   // append will proceed successfully as if the seed DB were empty.
   EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _));
   EXPECT_CALL(*this, AppendDecodeStatsCB(true));
   const DecodeStatsEntry entry(50, 1, 5);
   in_memory_db_->AppendDecodeStats(
       kTestKey(), entry,
       base::BindOnce(&InMemoryDBTestBase::AppendDecodeStatsCB,
                      base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
   ::testing::Mock::VerifyAndClear(this);

   // Reading the appended data works without issue and does not trigger new
   // queries to the seed DB.
   EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _)).Times(0);
   EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(entry))));
   in_memory_db_->GetDecodeStats(
       kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
                                  base::Unretained(this)));

   scoped_task_environment_.RunUntilIdle();
 }

 TEST_F(SeededInMemoryDBTest, SeedDBTearDownRace) {
   ::testing::FLAGS_gtest_death_test_style = "threadsafe";

   // Establish depends-on connection from InMemoryDB to SeedDB.
   InitializeEmptyDB();

   // Clearing the seed-db dependency should trigger a crash.
   EXPECT_CHECK_DEATH(seed_db_.reset());
 }

 }  // namespace media
	// Copyright 2018 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 <memory>

	#include "base/bind.h"
	#include "base/bind_helpers.h"
	#include "base/logging.h"
	#include "base/memory/ptr_util.h"
	#include "base/test/gtest_util.h"
	#include "base/test/scoped_task_environment.h"
	#include "media/capabilities/in_memory_video_decode_stats_db_impl.h"
	#include "media/capabilities/video_decode_stats_db_impl.h"
	#include "media/capabilities/video_decode_stats_db_provider.h"
	#include "testing/gmock/include/gmock/gmock.h"
	#include "testing/gtest/include/gtest/gtest.h"

	using testing::_;
	using testing::Eq;
	using testing::Pointee;
	using testing::IsNull;

	namespace media {

	static VideoDecodeStatsDB::VideoDescKey kTestKey() {
	return VideoDecodeStatsDB::VideoDescKey::MakeBucketedKey(
	VP9PROFILE_PROFILE3, gfx::Size(1024, 768), 60, "com.widevine.alpha",
	false);
	}

	static VideoDecodeStatsDB::DecodeStatsEntry kEmtpyEntry() {
	return VideoDecodeStatsDB::DecodeStatsEntry(0, 0, 0);
	}

	class MockSeedDB : public VideoDecodeStatsDB {
	public:
	MockSeedDB() = default;
	~MockSeedDB() override = default;

	MOCK_METHOD1(Initialize, void(InitializeCB init_cb));
	MOCK_METHOD3(AppendDecodeStats,
	void(const VideoDescKey& key,
	const DecodeStatsEntry& entry,
	AppendDecodeStatsCB append_done_cb));
	MOCK_METHOD2(GetDecodeStats,
	void(const VideoDescKey& key, GetDecodeStatsCB get_stats_cb));
	MOCK_METHOD1(ClearStats, void(base::OnceClosure destroy_done_cb));
	};

	class MockDBProvider : public VideoDecodeStatsDBProvider {
	public:
	MockDBProvider() = default;
	~MockDBProvider() override = default;

	MOCK_METHOD1(GetVideoDecodeStatsDB, void(GetCB get_db_b));
	};

	template <bool WithSeedDB>
	class InMemoryDBTestBase : public testing::Test {
	public:
	InMemoryDBTestBase()
	: seed_db_(WithSeedDB ? new MockSeedDB() : nullptr),
	db_provider_(WithSeedDB ? new MockDBProvider() : nullptr),
	in_memory_db_(new InMemoryVideoDecodeStatsDBImpl(db_provider_.get())) {
	// Setup MockDBProvider to provide the seed DB. No need to initialize the
	// DB here since it too is a Mock.
	if (db_provider_) {
	using GetCB = VideoDecodeStatsDBProvider::GetCB;
	ON_CALL(*db_provider_, GetVideoDecodeStatsDB(_))
	.WillByDefault([&](GetCB cb) { std::move(cb).Run(seed_db_.get()); });
	}

	// The InMemoryDB should NEVER modify the seed DB.
	if (seed_db_) {
	EXPECT_CALL(*seed_db_, AppendDecodeStats(_, _, _)).Times(0);
	EXPECT_CALL(*seed_db_, ClearStats(_)).Times(0);
	}
	}

	void InitializeEmptyDB() {
	if (seed_db_)
	EXPECT_CALL(*db_provider_, GetVideoDecodeStatsDB(_));

	EXPECT_CALL(*this, InitializeCB(true));

	in_memory_db_->Initialize(base::BindOnce(&InMemoryDBTestBase::InitializeCB,
	base::Unretained(this)));
	scoped_task_environment_.RunUntilIdle();
	}

	MOCK_METHOD1(InitializeCB, void(bool success));
	MOCK_METHOD1(AppendDecodeStatsCB, void(bool success));
	MOCK_METHOD2(
	GetDecodeStatsCB,
	void(bool success,
	std::unique_ptr<VideoDecodeStatsDB::DecodeStatsEntry> entry));
	MOCK_METHOD0(ClearStatsCB, void());

	protected:
	using VideoDescKey = media::VideoDecodeStatsDB::VideoDescKey;
	using DecodeStatsEntry = media::VideoDecodeStatsDB::DecodeStatsEntry;

	base::test::ScopedTaskEnvironment scoped_task_environment_;
	std::unique_ptr<MockSeedDB> seed_db_;
	std::unique_ptr<MockDBProvider> db_provider_;
	std::unique_ptr<InMemoryVideoDecodeStatsDBImpl> in_memory_db_;
	};

	// Specialization for tests that have/lack a seed DB. Some tests only make sense
	// with seed DB, so we separate them.
	class SeededInMemoryDBTest : public InMemoryDBTestBase<true> {};
	class SeedlessInMemoryDBTest : public InMemoryDBTestBase<false> {};

	TEST_F(SeedlessInMemoryDBTest, ReadExpectingEmpty) {
	InitializeEmptyDB();

	// Database is empty, seed DB is empty => expect empty stats entry.
	EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(kEmtpyEntry()))));

	in_memory_db_->GetDecodeStats(
	kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	}

	TEST_F(SeededInMemoryDBTest, ReadExpectingEmpty) {
	InitializeEmptyDB();

	// Make seed DB return null (empty) for this request.
	EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _))
	.WillOnce([](const auto& key, auto get_cb) {
	std::move(get_cb).Run(true, nullptr);
	});

	// Database is empty, seed DB is empty => expect empty stats entry.
	EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(kEmtpyEntry()))));

	in_memory_db_->GetDecodeStats(
	kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	}

	TEST_F(SeededInMemoryDBTest, ReadExpectingSeedData) {
	InitializeEmptyDB();

	// Setup seed DB to return an entry for the test key.
	DecodeStatsEntry seed_entry(1000, 2, 10);

	EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _))
	.WillOnce([&](const auto& key, auto get_cb) {
	std::move(get_cb).Run(true,
	std::make_unique<DecodeStatsEntry>(seed_entry));
	});

	// Seed DB has a an entry for the test key. Expect it!
	EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(seed_entry))));

	in_memory_db_->GetDecodeStats(
	kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	::testing::Mock::VerifyAndClear(this);

	// Verify a second GetDecodeStats() call with the same key does not trigger a
	// second call to the seed DB (we cache it).
	EXPECT_CALL(*seed_db_, GetDecodeStats(_, _)).Times(0);
	EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(seed_entry))));
	in_memory_db_->GetDecodeStats(
	kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	}

	TEST_F(SeededInMemoryDBTest, AppendReadAndClear) {
	const DecodeStatsEntry seed_entry(1000, 2, 10);
	const DecodeStatsEntry double_seed_entry(2000, 4, 20);
	const DecodeStatsEntry triple_seed_entry(3000, 6, 30);

	InitializeEmptyDB();

	// Setup seed DB to always return an entry for the test key.
	ON_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _))
	.WillByDefault([&](const auto& key, auto get_cb) {
	std::move(get_cb).Run(true,
	std::make_unique<DecodeStatsEntry>(seed_entry));
	});

	// First append should trigger a request for the same key from the seed DB.
	// Simulate a successful read providing seed_entry for that key.
	EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _));

	// Append the same seed entry, doubling the stats for this key.
	EXPECT_CALL(*this, AppendDecodeStatsCB(true));
	in_memory_db_->AppendDecodeStats(
	kTestKey(), seed_entry,
	base::BindOnce(&InMemoryDBTestBase::AppendDecodeStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	::testing::Mock::VerifyAndClear(this);

	// Seed DB should not be queried again for this key.
	EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _)).Times(0);

	// Now verify that the stats were doubled by the append above.
	EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(double_seed_entry))));
	in_memory_db_->GetDecodeStats(
	kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	::testing::Mock::VerifyAndClear(this);

	// Append the same seed entry again to triple the stats. Additional appends
	// should not trigger queries the seed DB for this key.
	EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _)).Times(0);
	in_memory_db_->AppendDecodeStats(
	kTestKey(), seed_entry,
	base::BindOnce(&InMemoryDBTestBase::AppendDecodeStatsCB,
	base::Unretained(this)));

	// Verify we have 3x the stats.
	EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(triple_seed_entry))));
	in_memory_db_->GetDecodeStats(
	kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
	base::Unretained(this)));

	// Now destroy the in-memory stats...
	EXPECT_CALL(*this, ClearStatsCB());
	in_memory_db_->ClearStats(base::BindOnce(&InMemoryDBTestBase::ClearStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	::testing::Mock::VerifyAndClear(this);

	// With in-memory stats now gone, GetDecodeStats(kTestKey()) should again
	// trigger a call to the seed DB and return the un-doubled seed stats.
	EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _));
	EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(seed_entry))));
	in_memory_db_->GetDecodeStats(
	kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	}

	TEST_F(SeedlessInMemoryDBTest, AppendReadAndClear) {
	const DecodeStatsEntry entry(50, 1, 5);
	const DecodeStatsEntry double_entry(100, 2, 10);

	InitializeEmptyDB();

	// Expect successful append to the empty seedless DB.
	EXPECT_CALL(*this, AppendDecodeStatsCB(true));
	in_memory_db_->AppendDecodeStats(
	kTestKey(), entry,
	base::BindOnce(&InMemoryDBTestBase::AppendDecodeStatsCB,
	base::Unretained(this)));

	// Verify stats can be read back.
	EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(entry))));
	in_memory_db_->GetDecodeStats(
	kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	::testing::Mock::VerifyAndClear(this);

	// Append same stats again to test summation.
	EXPECT_CALL(*this, AppendDecodeStatsCB(true));
	in_memory_db_->AppendDecodeStats(
	kTestKey(), entry,
	base::BindOnce(&InMemoryDBTestBase::AppendDecodeStatsCB,
	base::Unretained(this)));

	// Verify doubled stats can be read back.
	EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(double_entry))));
	in_memory_db_->GetDecodeStats(
	kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	::testing::Mock::VerifyAndClear(this);

	// Now destroy the in-memory stats...
	EXPECT_CALL(*this, ClearStatsCB());
	in_memory_db_->ClearStats(base::BindOnce(&InMemoryDBTestBase::ClearStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	::testing::Mock::VerifyAndClear(this);

	// Verify DB now empty for this key.
	EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(kEmtpyEntry()))));
	in_memory_db_->GetDecodeStats(
	kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	}

	TEST_F(SeededInMemoryDBTest, ProvidedNullSeedDB) {
	// DB provider may provide a null seed DB if it encounters some error.
	EXPECT_CALL(*db_provider_, GetVideoDecodeStatsDB(_))
	.WillOnce([](auto get_db_cb) { std::move(get_db_cb).Run(nullptr); });

	// Failing to obtain the seed DB is not a show stopper. The in-memory DB
	// should simply carry on in a seedless fashion.
	EXPECT_CALL(*this, InitializeCB(true));
	in_memory_db_->Initialize(base::BindOnce(&InMemoryDBTestBase::InitializeCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	::testing::Mock::VerifyAndClear(this);

	// Writes still succeed.
	EXPECT_CALL(*this, AppendDecodeStatsCB(true));
	const DecodeStatsEntry entry(50, 1, 5);
	in_memory_db_->AppendDecodeStats(
	kTestKey(), entry,
	base::BindOnce(&InMemoryDBTestBase::AppendDecodeStatsCB,
	base::Unretained(this)));

	// Reads should still succeed.
	EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(entry))));
	in_memory_db_->GetDecodeStats(
	kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	}

	TEST_F(SeededInMemoryDBTest, SeedReadFailureOnGettingStats) {
	// Everything seems fine at initialization...
	InitializeEmptyDB();

	// But seed DB will repeatedly fail to provide stats.
	ON_CALL(*seed_db_, GetDecodeStats(_, _))
	.WillByDefault([](const auto& key, auto get_cb) {
	std::move(get_cb).Run(false, nullptr);
	});

	// Reading the in-memory will still try to read the seed DB, and the read
	// callback will simply report that the DB is empty for this key.
	EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _));
	EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(kEmtpyEntry()))));
	in_memory_db_->GetDecodeStats(
	kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	}

	TEST_F(SeededInMemoryDBTest, SeedReadFailureOnAppendingingStats) {
	// Everything seems fine at initialization...
	InitializeEmptyDB();

	// But seed DB will repeatedly fail to provide stats.
	ON_CALL(*seed_db_, GetDecodeStats(_, _))
	.WillByDefault([](const auto& key, auto get_cb) {
	std::move(get_cb).Run(false, nullptr);
	});

	// Appending to the in-memory will still try to read the seed DB, and the
	// append will proceed successfully as if the seed DB were empty.
	EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _));
	EXPECT_CALL(*this, AppendDecodeStatsCB(true));
	const DecodeStatsEntry entry(50, 1, 5);
	in_memory_db_->AppendDecodeStats(
	kTestKey(), entry,
	base::BindOnce(&InMemoryDBTestBase::AppendDecodeStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	::testing::Mock::VerifyAndClear(this);

	// Reading the appended data works without issue and does not trigger new
	// queries to the seed DB.
	EXPECT_CALL(*seed_db_, GetDecodeStats(Eq(kTestKey()), _)).Times(0);
	EXPECT_CALL(*this, GetDecodeStatsCB(true, Pointee(Eq(entry))));
	in_memory_db_->GetDecodeStats(
	kTestKey(), base::BindOnce(&InMemoryDBTestBase::GetDecodeStatsCB,
	base::Unretained(this)));

	scoped_task_environment_.RunUntilIdle();
	}

	TEST_F(SeededInMemoryDBTest, SeedDBTearDownRace) {
	::testing::FLAGS_gtest_death_test_style = "threadsafe";

	// Establish depends-on connection from InMemoryDB to SeedDB.
	InitializeEmptyDB();

	// Clearing the seed-db dependency should trigger a crash.
	EXPECT_CHECK_DEATH(seed_db_.reset());
	}

	} // namespace media