diff --git a/build/Android.gtest.mk b/build/Android.gtest.mk
index 10b0400..380174e 100644
--- a/build/Android.gtest.mk
+++ b/build/Android.gtest.mk
@@ -90,9 +90,6 @@
   runtime/base/stringprintf_test.cc \
   runtime/base/timing_logger_test.cc \
   runtime/base/unix_file/fd_file_test.cc \
-  runtime/base/unix_file/null_file_test.cc \
-  runtime/base/unix_file/random_access_file_utils_test.cc \
-  runtime/base/unix_file/string_file_test.cc \
   runtime/class_linker_test.cc \
   runtime/dex_file_test.cc \
   runtime/dex_file_verifier_test.cc \
diff --git a/runtime/Android.mk b/runtime/Android.mk
index 7dfdb75..b362b73 100644
--- a/runtime/Android.mk
+++ b/runtime/Android.mk
@@ -31,9 +31,7 @@
   base/stringprintf.cc \
   base/timing_logger.cc \
   base/unix_file/fd_file.cc \
-  base/unix_file/null_file.cc \
   base/unix_file/random_access_file_utils.cc \
-  base/unix_file/string_file.cc \
   check_jni.cc \
   class_linker.cc \
   common_throws.cc \
diff --git a/runtime/base/unix_file/null_file.cc b/runtime/base/unix_file/null_file.cc
deleted file mode 100644
index 322c25a..0000000
--- a/runtime/base/unix_file/null_file.cc
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright (C) 2009 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "base/unix_file/null_file.h"
-#include <errno.h>
-
-namespace unix_file {
-
-NullFile::NullFile() {
-}
-
-NullFile::~NullFile() {
-}
-
-int NullFile::Close() {
-  return 0;
-}
-
-int NullFile::Flush() {
-  return 0;
-}
-
-int64_t NullFile::Read(char* buf ATTRIBUTE_UNUSED, int64_t byte_count ATTRIBUTE_UNUSED,
-                       int64_t offset) const {
-  if (offset < 0) {
-    return -EINVAL;
-  }
-  return 0;
-}
-
-int NullFile::SetLength(int64_t new_length) {
-  if (new_length < 0) {
-    return -EINVAL;
-  }
-  return 0;
-}
-
-int64_t NullFile::GetLength() const {
-  return 0;
-}
-
-int64_t NullFile::Write(const char* buf ATTRIBUTE_UNUSED, int64_t byte_count ATTRIBUTE_UNUSED,
-                        int64_t offset) {
-  if (offset < 0) {
-    return -EINVAL;
-  }
-  return byte_count;
-}
-
-}  // namespace unix_file
diff --git a/runtime/base/unix_file/null_file.h b/runtime/base/unix_file/null_file.h
deleted file mode 100644
index 3394731..0000000
--- a/runtime/base/unix_file/null_file.h
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright (C) 2009 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef ART_RUNTIME_BASE_UNIX_FILE_NULL_FILE_H_
-#define ART_RUNTIME_BASE_UNIX_FILE_NULL_FILE_H_
-
-#include "base/unix_file/random_access_file.h"
-#include "base/macros.h"
-
-namespace unix_file {
-
-// A RandomAccessFile implementation equivalent to /dev/null. Writes are
-// discarded, and there's no data to be read. Callers could use FdFile in
-// conjunction with /dev/null, but that's not portable and costs a file
-// descriptor. NullFile is "free".
-//
-// Thread safe.
-class NullFile : public RandomAccessFile {
- public:
-  NullFile();
-  virtual ~NullFile();
-
-  // RandomAccessFile API.
-  virtual int Close();
-  virtual int Flush();
-  virtual int64_t Read(char* buf, int64_t byte_count, int64_t offset) const;
-  virtual int SetLength(int64_t new_length);
-  virtual int64_t GetLength() const;
-  virtual int64_t Write(const char* buf, int64_t byte_count, int64_t offset);
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(NullFile);
-};
-
-}  // namespace unix_file
-
-#endif  // ART_RUNTIME_BASE_UNIX_FILE_NULL_FILE_H_
diff --git a/runtime/base/unix_file/null_file_test.cc b/runtime/base/unix_file/null_file_test.cc
deleted file mode 100644
index 410fdfc..0000000
--- a/runtime/base/unix_file/null_file_test.cc
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- * Copyright (C) 2009 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "base/unix_file/null_file.h"
-
-#include <errno.h>
-
-#include "gtest/gtest.h"
-
-namespace unix_file {
-
-class NullFileTest : public testing::Test { };
-
-TEST_F(NullFileTest, Read) {
-  NullFile f;
-  char buf[256];
-  // You can't read a negative number of bytes...
-  ASSERT_EQ(-EINVAL, f.Read(buf, 0, -1));
-  // ...but everything else is fine (though you'll get no data).
-  ASSERT_EQ(0, f.Read(buf, 128, 0));
-  ASSERT_EQ(0, f.Read(buf, 128, 128));
-}
-
-TEST_F(NullFileTest, SetLength) {
-  NullFile f;
-  // You can't set a negative length...
-  ASSERT_EQ(-EINVAL, f.SetLength(-1));
-  // ...but everything else is fine.
-  ASSERT_EQ(0, f.SetLength(0));
-  ASSERT_EQ(0, f.SetLength(128));
-}
-
-TEST_F(NullFileTest, GetLength) {
-  const std::string content("hello");
-  NullFile f;
-  // The length is always 0.
-  ASSERT_EQ(0, f.GetLength());
-  ASSERT_EQ(content.size(), static_cast<uint64_t>(f.Write(content.data(), content.size(), 0)));
-  ASSERT_EQ(0, f.GetLength());
-}
-
-TEST_F(NullFileTest, Write) {
-  const std::string content("hello");
-  NullFile f;
-  // You can't write at a negative offset...
-  ASSERT_EQ(-EINVAL, f.Write(content.data(), content.size(), -128));
-  // But you can write anywhere else...
-  ASSERT_EQ(content.size(), static_cast<uint64_t>(f.Write(content.data(), content.size(), 0)));
-  ASSERT_EQ(content.size(), static_cast<uint64_t>(f.Write(content.data(), content.size(), 128)));
-  // ...though the file will remain empty.
-  ASSERT_EQ(0, f.GetLength());
-}
-
-}  // namespace unix_file
diff --git a/runtime/base/unix_file/random_access_file_utils_test.cc b/runtime/base/unix_file/random_access_file_utils_test.cc
deleted file mode 100644
index 9457d22..0000000
--- a/runtime/base/unix_file/random_access_file_utils_test.cc
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- * Copyright (C) 2009 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "base/unix_file/random_access_file_utils.h"
-#include "base/unix_file/fd_file.h"
-#include "base/unix_file/string_file.h"
-#include "gtest/gtest.h"
-
-namespace unix_file {
-
-class RandomAccessFileUtilsTest : public testing::Test { };
-
-TEST_F(RandomAccessFileUtilsTest, CopyFile) {
-  StringFile src;
-  StringFile dst;
-
-  const std::string content("hello");
-  src.Assign(content);
-  ASSERT_EQ(src.ToStringPiece(), content);
-  ASSERT_EQ(dst.ToStringPiece(), "");
-
-  ASSERT_TRUE(CopyFile(src, &dst));
-  ASSERT_EQ(src.ToStringPiece(), dst.ToStringPiece());
-}
-
-TEST_F(RandomAccessFileUtilsTest, BadSrc) {
-  FdFile src(-1, false);
-  StringFile dst;
-  ASSERT_FALSE(CopyFile(src, &dst));
-}
-
-TEST_F(RandomAccessFileUtilsTest, BadDst) {
-  StringFile src;
-  FdFile dst(-1, false);
-
-  // We need some source content to trigger a write.
-  // Copying an empty file is a no-op.
-  src.Assign("hello");
-
-  ASSERT_FALSE(CopyFile(src, &dst));
-}
-
-}  // namespace unix_file
diff --git a/runtime/base/unix_file/string_file.cc b/runtime/base/unix_file/string_file.cc
deleted file mode 100644
index ff0d0fa..0000000
--- a/runtime/base/unix_file/string_file.cc
+++ /dev/null
@@ -1,98 +0,0 @@
-/*
- * Copyright (C) 2009 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "base/unix_file/string_file.h"
-#include <errno.h>
-#include <algorithm>
-#include "base/logging.h"
-
-namespace unix_file {
-
-StringFile::StringFile() {
-}
-
-StringFile::~StringFile() {
-}
-
-int StringFile::Close() {
-  return 0;
-}
-
-int StringFile::Flush() {
-  return 0;
-}
-
-int64_t StringFile::Read(char *buf, int64_t byte_count, int64_t offset) const {
-  CHECK(buf);
-  CHECK_GE(byte_count, 0);
-
-  if (offset < 0) {
-    return -EINVAL;
-  }
-
-  const int64_t available_bytes = std::min(byte_count, GetLength() - offset);
-  if (available_bytes < 0) {
-    return 0;  // Not an error, but nothing for us to do, either.
-  }
-  memcpy(buf, data_.data() + offset, available_bytes);
-  return available_bytes;
-}
-
-int StringFile::SetLength(int64_t new_length) {
-  if (new_length < 0) {
-    return -EINVAL;
-  }
-  data_.resize(new_length);
-  return 0;
-}
-
-int64_t StringFile::GetLength() const {
-  return data_.size();
-}
-
-int64_t StringFile::Write(const char *buf, int64_t byte_count, int64_t offset) {
-  CHECK(buf);
-  CHECK_GE(byte_count, 0);
-
-  if (offset < 0) {
-    return -EINVAL;
-  }
-
-  if (byte_count == 0) {
-    return 0;
-  }
-
-  // FUSE seems happy to allow writes past the end. (I'd guess it doesn't
-  // synthesize a write of zero bytes so that we're free to implement sparse
-  // files.) GNU as(1) seems to require such writes. Those files are small.
-  const int64_t bytes_past_end = offset - GetLength();
-  if (bytes_past_end > 0) {
-    data_.append(bytes_past_end, '\0');
-  }
-
-  data_.replace(offset, byte_count, buf, byte_count);
-  return byte_count;
-}
-
-void StringFile::Assign(const art::StringPiece &new_data) {
-  data_.assign(new_data.data(), new_data.size());
-}
-
-const art::StringPiece StringFile::ToStringPiece() const {
-  return data_;
-}
-
-}  // namespace unix_file
diff --git a/runtime/base/unix_file/string_file.h b/runtime/base/unix_file/string_file.h
deleted file mode 100644
index 26904f8..0000000
--- a/runtime/base/unix_file/string_file.h
+++ /dev/null
@@ -1,59 +0,0 @@
-/*
- * Copyright (C) 2009 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef ART_RUNTIME_BASE_UNIX_FILE_STRING_FILE_H_
-#define ART_RUNTIME_BASE_UNIX_FILE_STRING_FILE_H_
-
-#include <stdint.h>
-
-#include <string>
-
-#include "base/macros.h"
-#include "base/stringpiece.h"
-#include "base/unix_file/random_access_file.h"
-
-namespace unix_file {
-
-// A RandomAccessFile implementation backed by a std::string. (That is, all data is
-// kept in memory.)
-//
-// Not thread safe.
-class StringFile : public RandomAccessFile {
- public:
-  StringFile();
-  virtual ~StringFile();
-
-  // RandomAccessFile API.
-  virtual int Close();
-  virtual int Flush();
-  virtual int64_t Read(char* buf, int64_t byte_count, int64_t offset) const;
-  virtual int SetLength(int64_t new_length);
-  virtual int64_t GetLength() const;
-  virtual int64_t Write(const char* buf, int64_t byte_count, int64_t offset);
-
-  // Bonus API.
-  void Assign(const art::StringPiece& new_data);
-  const art::StringPiece ToStringPiece() const;
-
- private:
-  std::string data_;
-
-  DISALLOW_COPY_AND_ASSIGN(StringFile);
-};
-
-}  // namespace unix_file
-
-#endif  // ART_RUNTIME_BASE_UNIX_FILE_STRING_FILE_H_
diff --git a/runtime/base/unix_file/string_file_test.cc b/runtime/base/unix_file/string_file_test.cc
deleted file mode 100644
index 8821461..0000000
--- a/runtime/base/unix_file/string_file_test.cc
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * Copyright (C) 2009 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "base/unix_file/string_file.h"
-#include "base/unix_file/random_access_file_test.h"
-#include "gtest/gtest.h"
-
-namespace unix_file {
-
-class StringFileTest : public RandomAccessFileTest {
- protected:
-  virtual RandomAccessFile* MakeTestFile() {
-    return new StringFile;
-  }
-};
-
-TEST_F(StringFileTest, Read) {
-  TestRead();
-}
-
-TEST_F(StringFileTest, SetLength) {
-  TestSetLength();
-}
-
-TEST_F(StringFileTest, Write) {
-  TestWrite();
-}
-
-}  // namespace unix_file
diff --git a/runtime/closure.h b/runtime/closure.h
deleted file mode 100644
index 9bea28f..0000000
--- a/runtime/closure.h
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- * Copyright (C) 2012 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef ART_RUNTIME_CLOSURE_H_
-#define ART_RUNTIME_CLOSURE_H_
-
-namespace art {
-
-class Thread;
-
-class Closure {
- public:
-  virtual ~Closure() { }
-  virtual void Run(Thread* self) = 0;
-};
-
-}  // namespace art
-
-#endif  // ART_RUNTIME_CLOSURE_H_
diff --git a/runtime/strutil.h b/runtime/strutil.h
deleted file mode 100644
index c8d39e2..0000000
--- a/runtime/strutil.h
+++ /dev/null
@@ -1,40 +0,0 @@
-/*
- * Copyright (C) 2011 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef ART_RUNTIME_STRUTIL_H_
-#define ART_RUNTIME_STRUTIL_H_
-
-#include <string.h>
-
-namespace art {
-
-// Key comparison function for C strings.
-struct CStringLt {
-  bool operator()(const char* s1, const char* s2) const {
-    return strcmp(s1, s2) < 0;
-  }
-};
-
-// Key equality function for C strings.
-struct CStringEq {
-  bool operator()(const char* s1, const char* s2) const {
-    return strcmp(s1, s2) == 0;
-  }
-};
-
-}  // namespace art
-
-#endif  // ART_RUNTIME_STRUTIL_H_
diff --git a/runtime/thread_pool.h b/runtime/thread_pool.h
index d6330c8..8c08067 100644
--- a/runtime/thread_pool.h
+++ b/runtime/thread_pool.h
@@ -22,13 +22,18 @@
 
 #include "barrier.h"
 #include "base/mutex.h"
-#include "closure.h"
 #include "mem_map.h"
 
 namespace art {
 
 class ThreadPool;
 
+class Closure {
+ public:
+  virtual ~Closure() { }
+  virtual void Run(Thread* self) = 0;
+};
+
 class Task : public Closure {
  public:
   // Called when references reaches 0.