diff --git a/chrome/browser/command_updater_impl.cc b/chrome/browser/command_updater_impl.cc
new file mode 100644
index 0000000..2109874
--- /dev/null
+++ b/chrome/browser/command_updater_impl.cc
@@ -0,0 +1,104 @@
+// Copyright 2017 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 "chrome/browser/command_updater_impl.h"
+
+#include <algorithm>
+
+#include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "base/observer_list.h"
+#include "chrome/browser/command_observer.h"
+#include "chrome/browser/command_updater_delegate.h"
+
+class CommandUpdaterImpl::Command {
+ public:
+  bool enabled;
+  base::ObserverList<CommandObserver> observers;
+
+  Command() : enabled(true) {}
+};
+
+CommandUpdaterImpl::CommandUpdaterImpl(CommandUpdaterDelegate* delegate)
+    : delegate_(delegate) {
+}
+
+CommandUpdaterImpl::~CommandUpdaterImpl() {
+}
+
+bool CommandUpdaterImpl::SupportsCommand(int id) const {
+  return commands_.find(id) != commands_.end();
+}
+
+bool CommandUpdaterImpl::IsCommandEnabled(int id) const {
+  auto command = commands_.find(id);
+  if (command == commands_.end())
+    return false;
+  return command->second->enabled;
+}
+
+bool CommandUpdaterImpl::ExecuteCommand(int id) {
+  return ExecuteCommandWithDisposition(id, WindowOpenDisposition::CURRENT_TAB);
+}
+
+bool CommandUpdaterImpl::ExecuteCommandWithDisposition(
+    int id,
+    WindowOpenDisposition disposition) {
+  if (SupportsCommand(id) && IsCommandEnabled(id)) {
+    delegate_->ExecuteCommandWithDisposition(id, disposition);
+    return true;
+  }
+  return false;
+}
+
+void CommandUpdaterImpl::AddCommandObserver(int id, CommandObserver* observer) {
+  GetCommand(id, true)->observers.AddObserver(observer);
+}
+
+void CommandUpdaterImpl::RemoveCommandObserver(
+    int id, CommandObserver* observer) {
+  GetCommand(id, false)->observers.RemoveObserver(observer);
+}
+
+void CommandUpdaterImpl::RemoveCommandObserver(CommandObserver* observer) {
+  for (const auto& command_pair : commands_) {
+    Command* command = command_pair.second.get();
+    if (command)
+      command->observers.RemoveObserver(observer);
+  }
+}
+
+bool CommandUpdaterImpl::UpdateCommandEnabled(int id, bool enabled) {
+  Command* command = GetCommand(id, true);
+  if (command->enabled == enabled)
+    return true;  // Nothing to do.
+  command->enabled = enabled;
+  for (auto& observer : command->observers)
+    observer.EnabledStateChangedForCommand(id, enabled);
+  return true;
+}
+
+void CommandUpdaterImpl::DisableAllCommands() {
+  for (const auto& command_pair : commands_)
+    UpdateCommandEnabled(command_pair.first, false);
+}
+
+std::vector<int> CommandUpdaterImpl::GetAllIds() {
+  std::vector<int> result;
+  for (const auto& command_pair : commands_)
+    result.push_back(command_pair.first);
+  return result;
+}
+
+CommandUpdaterImpl::Command*
+CommandUpdaterImpl::GetCommand(int id, bool create) {
+  bool supported = SupportsCommand(id);
+  if (supported)
+    return commands_[id].get();
+
+  DCHECK(create);
+  std::unique_ptr<Command>& entry = commands_[id];
+  entry = base::MakeUnique<Command>();
+  return entry.get();
+}