diff --git a/base/win/text_services_message_filter.cc b/base/win/text_services_message_filter.cc
new file mode 100644
index 0000000..7ce233d
--- /dev/null
+++ b/base/win/text_services_message_filter.cc
@@ -0,0 +1,82 @@
+// Copyright (c) 2012 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/win/text_services_message_filter.h"
+
+namespace base {
+namespace win {
+
+TextServicesMessageFilter::TextServicesMessageFilter()
+    : client_id_(TF_CLIENTID_NULL),
+      is_initialized_(false) {
+}
+
+TextServicesMessageFilter::~TextServicesMessageFilter() {
+  if (is_initialized_)
+    thread_mgr_->Deactivate();
+}
+
+bool TextServicesMessageFilter::Init() {
+  if (FAILED(thread_mgr_.CreateInstance(CLSID_TF_ThreadMgr)))
+    return false;
+
+  if (FAILED(message_pump_.QueryFrom(thread_mgr_)))
+    return false;
+
+  if (FAILED(keystroke_mgr_.QueryFrom(thread_mgr_)))
+    return false;
+
+  if (FAILED(thread_mgr_->Activate(&client_id_)))
+    return false;
+
+  is_initialized_ = true;
+  return is_initialized_;
+}
+
+// Wraps for ITfMessagePump::PeekMessage with win32 PeekMessage signature.
+// Obtains messages from application message queue.
+BOOL TextServicesMessageFilter::DoPeekMessage(MSG* msg,
+                                              HWND window_handle,
+                                              UINT msg_filter_min,
+                                              UINT msg_filter_max,
+                                              UINT remove_msg) {
+  BOOL result = FALSE;
+  if (FAILED(message_pump_->PeekMessage(msg, window_handle,
+                                        msg_filter_min, msg_filter_max,
+                                        remove_msg, &result))) {
+    result = FALSE;
+  }
+
+  return result;
+}
+
+// Sends message to Text Service Manager.
+// The message will be used to input composition text.
+// Returns true if |message| was consumed by text service manager.
+bool TextServicesMessageFilter::ProcessMessage(const MSG& msg) {
+  if (msg.message == WM_KEYDOWN) {
+    BOOL eaten = FALSE;
+    HRESULT hr = keystroke_mgr_->TestKeyDown(msg.wParam, msg.lParam, &eaten);
+    if (FAILED(hr) && !eaten)
+      return false;
+    eaten = FALSE;
+    hr = keystroke_mgr_->KeyDown(msg.wParam, msg.lParam, &eaten);
+    return (SUCCEEDED(hr) && !!eaten);
+  }
+
+  if (msg.message == WM_KEYUP) {
+    BOOL eaten = FALSE;
+    HRESULT hr = keystroke_mgr_->TestKeyUp(msg.wParam, msg.lParam, &eaten);
+    if (FAILED(hr) && !eaten)
+      return false;
+    eaten = FALSE;
+    hr = keystroke_mgr_->KeyUp(msg.wParam, msg.lParam, &eaten);
+    return (SUCCEEDED(hr) && !!eaten);
+  }
+
+  return false;
+}
+
+}  // namespace win
+}  // namespace base