diff --git a/DEPS b/DEPS
index b2982369bed364..90d5fd55b9acf6 100644
--- a/DEPS
+++ b/DEPS
@@ -1012,7 +1012,7 @@ deps = {
   },
 
   'src/third_party/leveldatabase/src':
-    Var('chromium_git') + '/external/leveldb.git' + '@' + 'fe4494804f5e3a2e25485d32aeb0eb7d2f25732e',
+    Var('chromium_git') + '/external/leveldb.git' + '@' + '9ce30510d482f5b2fa2965201453f0fc914f700c',
 
   'src/third_party/libFuzzer/src':
     Var('chromium_git') + '/chromium/llvm-project/compiler-rt/lib/fuzzer.git' + '@' +  Var('libfuzzer_revision'),
diff --git a/components/services/leveldb/env_mojo.cc b/components/services/leveldb/env_mojo.cc
index fc656fefc05270..86bbf050ff4668 100644
--- a/components/services/leveldb/env_mojo.cc
+++ b/components/services/leveldb/env_mojo.cc
@@ -18,6 +18,10 @@
 #include "third_party/leveldatabase/chromium_logger.h"
 #include "third_party/leveldatabase/src/include/leveldb/status.h"
 
+#if defined(OS_WIN) && defined(DeleteFile)
+#undef DeleteFile
+#endif
+
 using leveldb_env::UMALogger;
 
 namespace leveldb {
diff --git a/components/services/leveldb/env_mojo.h b/components/services/leveldb/env_mojo.h
index 9748900cff2738..362c3d9a1bfb18 100644
--- a/components/services/leveldb/env_mojo.h
+++ b/components/services/leveldb/env_mojo.h
@@ -8,11 +8,18 @@
 #include <string>
 #include <vector>
 
+#include "build/build_config.h"
 #include "components/services/filesystem/public/interfaces/directory.mojom.h"
 #include "components/services/leveldb/leveldb_mojo_proxy.h"
 #include "third_party/leveldatabase/env_chromium.h"
 #include "third_party/leveldatabase/src/include/leveldb/env.h"
 
+#if defined(OS_WIN) && defined(DeleteFile)
+// See comment in env.h.
+#undef DeleteFile
+#define ENV_MOJO_DELETEFILE_UNDEFINED
+#endif  // defined(OS_WIN) && defined(DeleteFile)
+
 namespace leveldb {
 
 class MojoRetrierProvider {
@@ -87,4 +94,9 @@ class MojoEnv : public Env,
 
 }  // namespace leveldb
 
+// Redefine DeleteFile if necessary.
+#if defined(OS_WIN) && defined(ENV_MOJO_DELETEFILE_UNDEFINED)
+#define DeleteFile DeleteFileW
+#endif
+
 #endif  // COMPONENTS_SERVICES_LEVELDB_ENV_MOJO_H_
diff --git a/third_party/leveldatabase/BUILD.gn b/third_party/leveldatabase/BUILD.gn
index 16a557291b6d37..3d32c4ad1d89c0 100644
--- a/third_party/leveldatabase/BUILD.gn
+++ b/third_party/leveldatabase/BUILD.gn
@@ -13,17 +13,6 @@ config("leveldb_config") {
     "src",
     "src/include",
   ]
-
-  if (is_win) {
-    # windows.h #defines DeleteFile to DeleteFileW on Unicode builds. This
-    # definition is in effect in a large part of Chromium's compilation units.
-    # leveldb::Env has a DeleteFile method, which becomes DeleteFileW when the
-    # definition is in effect.
-    #
-    # Define the macro everywhere, to avoid reasoning about which headers bring
-    # windows.h in.
-    defines += [ "DeleteFile=DeleteFileW" ]
-  }
 }
 
 leveldb_sources = [
diff --git a/third_party/leveldatabase/README.chromium b/third_party/leveldatabase/README.chromium
index 06f2ffecb8a347..9402317ede79ff 100644
--- a/third_party/leveldatabase/README.chromium
+++ b/third_party/leveldatabase/README.chromium
@@ -1,7 +1,7 @@
 Name: LevelDB: A Fast Persistent Key-Value Store
 Short Name: leveldb
 URL: https://github.com/google/leveldb.git
-Version: 1.20.git.7b945f200339aa47c24788d3ee9910c09c513843
+Version: 1.20.git.9ce30510d482f5b2fa2965201453f0fc914f700c
 License: New BSD
 License File: src/LICENSE
 Security Critical: yes
diff --git a/third_party/leveldatabase/env_chromium.cc b/third_party/leveldatabase/env_chromium.cc
index b43fbcad4c6778..6f5c1ab5338b27 100644
--- a/third_party/leveldatabase/env_chromium.cc
+++ b/third_party/leveldatabase/env_chromium.cc
@@ -42,6 +42,13 @@
 #include "third_party/leveldatabase/src/include/leveldb/options.h"
 #include "third_party/re2/src/re2/re2.h"
 
+#if defined(OS_WIN)
+#undef DeleteFile
+#define base_DeleteFile base::DeleteFileW
+#else  // defined(OS_WIN)
+#define base_DeleteFile base::DeleteFile
+#endif  // defined(OS_WIN)
+
 using base::FilePath;
 using base::trace_event::MemoryAllocatorDump;
 using base::trace_event::MemoryDumpArgs;
@@ -869,7 +876,7 @@ void ChromiumEnv::DeleteBackupFiles(const FilePath& dir) {
                                   FILE_PATH_LITERAL("*.bak"));
   for (base::FilePath fname = dir_reader.Next(); !fname.empty();
        fname = dir_reader.Next()) {
-    histogram->AddBoolean(base::DeleteFile(fname, false));
+    histogram->AddBoolean(base_DeleteFile(fname, false));
   }
 }
 
@@ -903,7 +910,7 @@ Status ChromiumEnv::DeleteFile(const std::string& fname) {
   Status result;
   FilePath fname_filepath = FilePath::FromUTF8Unsafe(fname);
   // TODO(jorlow): Should we assert this is a file?
-  if (!base::DeleteFile(fname_filepath, false)) {
+  if (!base_DeleteFile(fname_filepath, false)) {
     result = MakeIOError(fname, "Could not delete file.", kDeleteFile);
     RecordErrorAt(kDeleteFile);
   }
@@ -927,7 +934,7 @@ Status ChromiumEnv::CreateDir(const std::string& name) {
 Status ChromiumEnv::DeleteDir(const std::string& name) {
   Status result;
   // TODO(jorlow): Should we assert this is a directory?
-  if (!base::DeleteFile(FilePath::FromUTF8Unsafe(name), false)) {
+  if (!base_DeleteFile(FilePath::FromUTF8Unsafe(name), false)) {
     result = MakeIOError(name, "Could not delete directory.", kDeleteDir);
     RecordErrorAt(kDeleteDir);
   }
diff --git a/third_party/leveldatabase/env_chromium.h b/third_party/leveldatabase/env_chromium.h
index dfed32effc50f7..1927050c402e0c 100644
--- a/third_party/leveldatabase/env_chromium.h
+++ b/third_party/leveldatabase/env_chromium.h
@@ -19,6 +19,8 @@
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/metrics/histogram.h"
+#include "base/synchronization/condition_variable.h"
+#include "build/build_config.h"
 #include "leveldb/cache.h"
 #include "leveldb/db.h"
 #include "leveldb/env.h"
@@ -26,6 +28,12 @@
 #include "port/port_chromium.h"
 #include "util/mutexlock.h"
 
+#if defined(OS_WIN) && defined(DeleteFile)
+// See comment in env.h.
+#undef DeleteFile
+#define ENV_CHROMIUM_DELETEFILE_UNDEFINED
+#endif  // defined(OS_WIN) && defined(DeleteFile)
+
 namespace base {
 namespace trace_event {
 class MemoryAllocatorDump;
@@ -369,4 +377,9 @@ LEVELDB_EXPORT leveldb::Slice MakeSlice(const base::StringPiece& s);
 
 }  // namespace leveldb_env
 
+// Redefine DeleteFile if necessary.
+#if defined(OS_WIN) && defined(ENV_CHROMIUM_DELETEFILE_UNDEFINED)
+#define DeleteFile DeleteFileW
+#endif
+
 #endif  // THIRD_PARTY_LEVELDATABASE_ENV_CHROMIUM_H_
diff --git a/third_party/leveldatabase/env_chromium_unittest.cc b/third_party/leveldatabase/env_chromium_unittest.cc
index b0818d977b2ec2..9c9ea6bf0402f3 100644
--- a/third_party/leveldatabase/env_chromium_unittest.cc
+++ b/third_party/leveldatabase/env_chromium_unittest.cc
@@ -18,6 +18,7 @@
 #include "base/test/scoped_task_environment.h"
 #include "base/test/test_suite.h"
 #include "base/trace_event/process_memory_dump.h"
+#include "build/build_config.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/leveldatabase/env_chromium.h"
 #include "third_party/leveldatabase/leveldb_chrome.h"
@@ -27,6 +28,10 @@
 
 #define FPL FILE_PATH_LITERAL
 
+#if defined(OS_WIN) && defined(DeleteFile)
+#undef DeleteFile
+#endif
+
 using base::trace_event::MemoryDumpArgs;
 using base::trace_event::MemoryDumpLevelOfDetail;
 using base::trace_event::ProcessMemoryDump;
diff --git a/third_party/leveldatabase/leveldb_chrome.cc b/third_party/leveldatabase/leveldb_chrome.cc
index 5c15aabc98eb20..e84aacdb1d95e7 100644
--- a/third_party/leveldatabase/leveldb_chrome.cc
+++ b/third_party/leveldatabase/leveldb_chrome.cc
@@ -21,10 +21,18 @@
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/memory_dump_provider.h"
 #include "base/trace_event/process_memory_dump.h"
+#include "build/build_config.h"
 #include "third_party/leveldatabase/env_chromium.h"
 #include "third_party/leveldatabase/src/helpers/memenv/memenv.h"
 #include "util/mutexlock.h"
 
+#if defined(OS_WIN)
+#undef DeleteFile
+#define base_DeleteFile base::DeleteFileW
+#else  // defined(OS_WIN)
+#define base_DeleteFile base::DeleteFile
+#endif  // defined(OS_WIN)
+
 using MemoryPressureLevel = base::MemoryPressureListener::MemoryPressureLevel;
 using base::trace_event::MemoryAllocatorDump;
 using base::trace_event::MemoryDumpArgs;
@@ -365,7 +373,7 @@ leveldb::Status DeleteDB(const base::FilePath& db_path,
 
   // TODO(cmumford): To be fully safe this implementation should acquire a lock
   // as there is some daylight in between DestroyDB and DeleteFile.
-  if (!base::DeleteFile(db_path, true)) {
+  if (!base_DeleteFile(db_path, true)) {
     // Only delete the directory when when DestroyDB is successful. This is
     // because DestroyDB checks for database locks, and will fail if in use.
     return leveldb::Status::IOError(db_path.AsUTF8Unsafe(), "Error deleting");
diff --git a/third_party/leveldatabase/port/port_chromium.cc b/third_party/leveldatabase/port/port_chromium.cc
index b84c6e0e4c00e7..570035d23f39aa 100644
--- a/third_party/leveldatabase/port/port_chromium.cc
+++ b/third_party/leveldatabase/port/port_chromium.cc
@@ -6,48 +6,12 @@
 
 #include <string>
 
-#include "base/threading/platform_thread.h"
 #include "third_party/crc32c/src/include/crc32c/crc32c.h"
 #include "third_party/snappy/src/snappy.h"
-#include "util/logging.h"
 
 namespace leveldb {
 namespace port {
 
-Mutex::Mutex() = default;
-
-Mutex::~Mutex() = default;
-
-void Mutex::Lock() {
-  mu_.Acquire();
-}
-
-void Mutex::Unlock() {
-  mu_.Release();
-}
-
-void Mutex::AssertHeld() {
-  mu_.AssertAcquired();
-}
-
-CondVar::CondVar(Mutex* mu)
-    : cv_(&mu->mu_) {
-}
-
-CondVar::~CondVar() = default;
-
-void CondVar::Wait() {
-  cv_.Wait();
-}
-
-void CondVar::Signal(){
-  cv_.Signal();
-}
-
-void CondVar::SignalAll() {
-  cv_.Broadcast();
-}
-
 bool Snappy_Compress(const char* input,
                      size_t input_length,
                      std::string* output) {
diff --git a/third_party/leveldatabase/port/port_chromium.h b/third_party/leveldatabase/port/port_chromium.h
index f37cf52c44fa91..6a9f74e4ae9d65 100644
--- a/third_party/leveldatabase/port/port_chromium.h
+++ b/third_party/leveldatabase/port/port_chromium.h
@@ -7,16 +7,13 @@
 #ifndef STORAGE_LEVELDB_PORT_PORT_CHROMIUM_H_
 #define STORAGE_LEVELDB_PORT_PORT_CHROMIUM_H_
 
-#include <stddef.h>
-#include <stdint.h>
-
+#include <cassert>
+#include <condition_variable>  // NOLINT
 #include <cstring>
+#include <mutex>  // NOLINT
 #include <string>
 
-#include "base/atomicops.h"
 #include "base/macros.h"
-#include "base/synchronization/condition_variable.h"
-#include "base/synchronization/lock.h"
 #include "base/thread_annotations.h"
 #include "build/build_config.h"
 
@@ -28,56 +25,41 @@ static const bool kLittleEndian = true;
 
 class LOCKABLE Mutex {
  public:
-  Mutex();
-  ~Mutex();
-  void Lock() EXCLUSIVE_LOCK_FUNCTION();
-  void Unlock() UNLOCK_FUNCTION();
-  void AssertHeld() ASSERT_EXCLUSIVE_LOCK();
+  Mutex() = default;
+  ~Mutex() = default;
 
- private:
-  base::Lock mu_;
+  Mutex(const Mutex&) = delete;
+  Mutex& operator=(const Mutex&) = delete;
 
-  friend class CondVar;
-  DISALLOW_COPY_AND_ASSIGN(Mutex);
-};
-
-class CondVar {
- public:
-  explicit CondVar(Mutex* mu);
-  ~CondVar();
-  void Wait();
-  void Signal();
-  void SignalAll();
+  void Lock() EXCLUSIVE_LOCK_FUNCTION() { mu_.lock(); }
+  void Unlock() UNLOCK_FUNCTION() { mu_.unlock(); }
+  void AssertHeld() ASSERT_EXCLUSIVE_LOCK() {}
 
  private:
-  base::ConditionVariable cv_;
-
-  DISALLOW_COPY_AND_ASSIGN(CondVar);
+  friend class CondVar;
+  std::mutex mu_;
 };
 
-class AtomicPointer {
+// Thinly wraps std::condition_variable.
+class CondVar {
  public:
-  AtomicPointer() = default;
-  ~AtomicPointer() = default;
+  explicit CondVar(Mutex* mu) : mu_(mu) { assert(mu != nullptr); }
+  ~CondVar() = default;
 
-  explicit AtomicPointer(void* p) : rep_(reinterpret_cast<Rep>(p)) {}
+  CondVar(const CondVar&) = delete;
+  CondVar& operator=(const CondVar&) = delete;
 
-  inline void* Acquire_Load() const {
-    return reinterpret_cast<void*>(base::subtle::Acquire_Load(&rep_));
-  }
-  inline void Release_Store(void* v) {
-    base::subtle::Release_Store(&rep_, reinterpret_cast<Rep>(v));
-  }
-  inline void* NoBarrier_Load() const {
-    return reinterpret_cast<void*>(base::subtle::NoBarrier_Load(&rep_));
-  }
-  inline void NoBarrier_Store(void* v) {
-    base::subtle::NoBarrier_Store(&rep_, reinterpret_cast<Rep>(v));
+  void Wait() {
+    std::unique_lock<std::mutex> lock(mu_->mu_, std::adopt_lock);
+    cv_.wait(lock);
+    lock.release();
   }
+  void Signal() { cv_.notify_one(); }
+  void SignalAll() { cv_.notify_all(); }
 
  private:
-  using Rep = base::subtle::AtomicWord;
-  Rep rep_;
+  std::condition_variable cv_;
+  Mutex* const mu_;
 };
 
 bool Snappy_Compress(const char* input, size_t input_length,