Enable NPAPI if policy has plugin policies.

chrome/browser/plugins/plugin_policy_handler.h

+// Copyright 2015 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_PLUGINS_PLUGIN_POLICY_HANDLER_H_
+#define CHROME_BROWSER_PLUGINS_PLUGIN_POLICY_HANDLER_H_
+
+#include "components/policy/core/browser/configuration_policy_handler.h"
+
+class PrefValueMap;
+
+namespace policy {
+
+class PolicyErrorMap;
+class PolicyMap;
+
+// ConfigurationPolicyHandler for the plugin policies that re-enable NPAPI.
+class PluginPolicyHandler : public ConfigurationPolicyHandler {

[Mattias Nissler (ping if slow), 2015/04/10 19:22:45]

It probably makes sense to rename PluginPolicyHandler to
NPApiEnabledPolicyHandler (or similar) to make the name reflect the behavior it
implements.

+ public:
+  PluginPolicyHandler();
+
+  ~PluginPolicyHandler() override;
+
+  // ConfigurationPolicyHandler methods:
+  void ApplyPolicySettings(const PolicyMap& policies,
+                           PrefValueMap* prefs) override;
+  // ConfigurationPolicyHandler methods:
+  bool CheckPolicySettings(const PolicyMap& policies,
+                           PolicyErrorMap* prefs) override;
+
+  DISALLOW_COPY_AND_ASSIGN(PluginPolicyHandler);

[Mattias Nissler (ping if slow), 2015/04/10 19:22:45]

nit: #include "base/macros.h"

+};
+
+}  // namespace policy
+
+#endif  // CHROME_BROWSER_PLUGINS_PLUGIN_POLICY_HANDLER_H_