Extension Storage API: expose storage quota information to extensions, via:

chrome/browser/extensions/settings/testing_settings_storage.cc

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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 "chrome/browser/extensions/settings/testing_settings_storage.h"
 
 #include "base/logging.h"
 
 namespace extensions {
 
 namespace {
@@ skipping 18 matching lines @@
 
 TestingSettingsStorage::TestingSettingsStorage()
     : fail_all_requests_(false) {}
 
 TestingSettingsStorage::~TestingSettingsStorage() {}
 
 void TestingSettingsStorage::SetFailAllRequests(bool fail_all_requests) {
   fail_all_requests_ = fail_all_requests;
 }
 
+size_t TestingSettingsStorage::GetBytesInUse(const std::string& key) {
+  // Let SettingsStorageQuotaEnforcer implement this.
+  NOTREACHED() << "Not implemented";
+  return 0;
+}
+
+size_t TestingSettingsStorage::GetBytesInUse(
+    const std::vector<std::string>& keys) {
+  // Let SettingsStorageQuotaEnforcer implement this.
+  NOTREACHED() << "Not implemented";
+  return 0;
+}
+
+size_t TestingSettingsStorage::GetBytesInUse() {
+  // Let SettingsStorageQuotaEnforcer implement this.
+  NOTREACHED() << "Not implemented";
+  return 0;
+}
+
 SettingsStorage::ReadResult TestingSettingsStorage::Get(
     const std::string& key) {
   return Get(CreateVector(key));
 }
 
 SettingsStorage::ReadResult TestingSettingsStorage::Get(
     const std::vector<std::string>& keys) {
   if (fail_all_requests_) {
     return ReadResultError();
   }
@@ skipping 74 matching lines @@
   }
 
   std::vector<std::string> keys;
   for (DictionaryValue::Iterator it(storage_); it.HasNext(); it.Advance()) {
     keys.push_back(it.key());
   }
   return Remove(keys);
 }
 
 }  // namespace extensions