Make policy errors available to display in about:policy.

chrome/browser/policy/policy_error_map.h

Index: chrome/browser/policy/policy_error_map.h
diff --git a/chrome/browser/policy/policy_error_map.h b/chrome/browser/policy/policy_error_map.h
new file mode 100644
index 0000000000000000000000000000000000000000..b031b227aff93347e4ca72c5912b4231a1b0277a
--- /dev/null
+++ b/chrome/browser/policy/policy_error_map.h
@@ -0,0 +1,77 @@
+// Copyright (c) 2011 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.
+
+#ifndef CHROME_BROWSER_POLICY_POLICY_ERROR_MAP_H_
+#define CHROME_BROWSER_POLICY_POLICY_ERROR_MAP_H_
+#pragma once
+
+#include <map>
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/string16.h"
+#include "base/values.h"
+#include "policy/configuration_policy_type.h"
+
+namespace policy {
+
+// Collects error messages and their associated policies.
+class PolicyErrorMap {
+ public:
+  typedef std::multimap<ConfigurationPolicyType, string16> PolicyMapType;
+  typedef PolicyMapType::const_iterator const_iterator;
+
+  PolicyErrorMap();
+  virtual ~PolicyErrorMap();
+
+  // Returns true when the errors logged are ready to be retrieved. It is always
+  // safe to call AddError, but the other methods are only allowed once
+  // IsReady is true. IsReady will be true once the UI message loop has started.
+  bool IsReady() const;
+
+  // Adds an entry with key |policy| and the error message corresponding to
+  // |message_id| in grit/generated_resources.h to the map.
+  void AddError(ConfigurationPolicyType policy, int message_id);
+
+  // Adds an entry with key |policy| and the error message corresponding to
+  // |message_id| in grit/generated_resources.h to the map and replaces the
+  // placeholder within the error message with |replacement_string|.
+  void AddError(ConfigurationPolicyType policy,
+                int message_id,
+                const std::string& replacement_string);
+
+  // Returns a list of all the error messages stored for |policy|. Returns NULL
+  // if there are no error messages for |policy. The caller acquires ownership
+  // of the returned ListValue pointer.
+  ListValue* GetErrors(ConfigurationPolicyType policy);
+
+  bool empty();
+  size_t size();
+
+  const_iterator begin();
+  const_iterator end();
+
+  void Clear();
+
+ private:
+  struct PendingError;
+
+  // Maps the error when ready, otherwise adds it to the pending errors list.
+  void AddError(const PendingError& error);
+
+  // Converts a PendingError into a |map_| entry.
+  void Convert(const PendingError& error);
+
+  // Converts all pending errors to |map_| entries.
+  void CheckReadyAndConvert();
+
+  std::vector<PendingError> pending_;
+  PolicyMapType map_;
+
+  DISALLOW_COPY_AND_ASSIGN(PolicyErrorMap);
+};
+
+}  // namespace policy
+
+#endif  // CHROME_BROWSER_POLICY_POLICY_ERROR_MAP_H_