Build a new TokenCacheService so I can stop using TokenService for something it wasn't designed for.

chrome/browser/extensions/token_cache/token_cache_service.cc

+// Copyright (c) 2013 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/extensions/token_cache/token_cache_service.h"
+
+#include "base/logging.h"
+#include "chrome/common/chrome_notification_types.h"
+#include "content/public/browser/notification_source.h"
+
+using base::Time;
+using base::TimeDelta;
+
+namespace extensions {
+
+TokenCacheService::TokenCacheService(Profile* profile) : profile_(profile) {
+  registrar_.Add(this,
+                 chrome::NOTIFICATION_GOOGLE_SIGNED_OUT,
+                 content::Source<Profile>(profile_));
+}
+
+TokenCacheService::~TokenCacheService() {
+}
+
+void TokenCacheService::StoreToken(const std::string& token_name,
+                                   const std::string& token_value,
+                                   base::TimeDelta time_to_live) {
+  TokenCacheData token_data;
+
+  // Get the current time, and make sure that the token has not already expired.
+  Time expiration_time;
+  TimeDelta zero_delta;
+
+  // Negative time deltas are meaningless to this function.
+  DCHECK(time_to_live >= zero_delta);
+
+  if (zero_delta < time_to_live) {
+    expiration_time = Time::Now();
+    expiration_time += time_to_live;
+  }
+
+  token_data.token = token_value;
+  token_data.expiration_time = expiration_time;
+
+  // Add the token to our cache, overwriting any existing token with this name.
+  token_cache_[token_name] = token_data;
+}
+
+// Retrieve a token for the currently logged in user.  This returns an empty
+// string if the token was not found or timed out.
+std::string TokenCacheService::RetrieveToken(const std::string& token_name) {
+  std::map<std::string, TokenCacheData>::iterator it =
+      token_cache_.find(token_name);
+
+  if (it != token_cache_.end()) {
+    Time now = Time::Now();
+    if (it->second.expiration_time.is_null() ||
+        now < it->second.expiration_time) {
+      return it->second.token;
+    } else {
+      // Remove this entry if it is expired.
+      token_cache_.erase(it);
+      return std::string();
+    }
+  }
+
+  return std::string();
+}
+
+// Inherited from NotificationObserver.
+void TokenCacheService::Observe(int type,
+                                const content::NotificationSource& source,
+                                const content::NotificationDetails& details)  {
+  DCHECK(chrome::NOTIFICATION_GOOGLE_SIGNED_OUT == type);
+  token_cache_.clear();
+}
+
+}  // namespace extensions