Revert of Revert of Clean up Smart Lock cryptohome keys logic:

chrome/browser/chromeos/login/easy_unlock/easy_unlock_refresh_keys_operation.cc

Index: chrome/browser/chromeos/login/easy_unlock/easy_unlock_refresh_keys_operation.cc
diff --git a/chrome/browser/chromeos/login/easy_unlock/easy_unlock_refresh_keys_operation.cc b/chrome/browser/chromeos/login/easy_unlock/easy_unlock_refresh_keys_operation.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0b98a6acc88ee45c200e7adaef5d728e0bc5b174
--- /dev/null
+++ b/chrome/browser/chromeos/login/easy_unlock/easy_unlock_refresh_keys_operation.cc
@@ -0,0 +1,64 @@
+// Copyright 2014 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/bind.h"
+#include "chrome/browser/chromeos/login/easy_unlock/easy_unlock_create_keys_operation.h"
+#include "chrome/browser/chromeos/login/easy_unlock/easy_unlock_refresh_keys_operation.h"
+#include "chrome/browser/chromeos/login/easy_unlock/easy_unlock_remove_keys_operation.h"
+
+namespace chromeos {
+
+EasyUnlockRefreshKeysOperation::EasyUnlockRefreshKeysOperation(
+    const UserContext& user_context,
+    const std::string& tpm_public_key,
+    const EasyUnlockDeviceKeyDataList& devices,
+    const RefreshKeysCallback& callback)
+    : user_context_(user_context),
+      tpm_public_key_(tpm_public_key),
+      devices_(devices),
+      callback_(callback),
+      weak_ptr_factory_(this) {
+}
+
+EasyUnlockRefreshKeysOperation::~EasyUnlockRefreshKeysOperation() {
+}
+
+void EasyUnlockRefreshKeysOperation::Start() {
+  if (devices_.empty()) {
+    OnKeysCreated(true);
+    return;
+  }
+
+  create_keys_operation_.reset(new EasyUnlockCreateKeysOperation(
+      user_context_, tpm_public_key_, devices_,
+      base::Bind(&EasyUnlockRefreshKeysOperation::OnKeysCreated,
+                 weak_ptr_factory_.GetWeakPtr())));
+  create_keys_operation_->Start();
+}
+
+void EasyUnlockRefreshKeysOperation::OnKeysCreated(bool success) {
+  if (!success) {
+    callback_.Run(false);
+    return;
+  }
+
+  // Update the user context to have the new authorization key after the create
+  // keys operation. This is necessary because the old authorization key
+  // associated with the user context will be invalidated after the create keys
+  // operation.
+  if (create_keys_operation_)
+    user_context_ = create_keys_operation_->user_context();
+
+  remove_keys_operation_.reset(new EasyUnlockRemoveKeysOperation(
+      user_context_, devices_.size(),
+      base::Bind(&EasyUnlockRefreshKeysOperation::OnKeysRemoved,
+                 weak_ptr_factory_.GetWeakPtr())));
+  remove_keys_operation_->Start();
+}
+
+void EasyUnlockRefreshKeysOperation::OnKeysRemoved(bool success) {
+  callback_.Run(success);
+}
+
+}  // namespace chromeos