Enable NPAPI if policy has plugin policies.

chrome/browser/policy/profile_policy_connector.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/policy/profile_policy_connector.h"
 
 #include <vector>
 
 #include "base/bind.h"
+#include "base/command_line.h"
 #include "base/logging.h"
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "components/policy/core/browser/browser_policy_connector.h"
 #include "components/policy/core/common/cloud/cloud_policy_core.h"
 #include "components/policy/core/common/cloud/cloud_policy_manager.h"
 #include "components/policy/core/common/cloud/cloud_policy_store.h"
 #include "components/policy/core/common/configuration_policy_provider.h"
 #include "components/policy/core/common/policy_service_impl.h"
 #include "components/policy/core/common/schema_registry_tracking_policy_provider.h"
+#include "content/public/browser/plugin_service.h"
+#include "content/public/common/content_switches.h"
 #include "google_apis/gaia/gaia_auth_util.h"
+#include "policy/policy_constants.h"
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
 #include "chrome/browser/chromeos/policy/device_cloud_policy_manager_chromeos.h"
 #include "chrome/browser/chromeos/policy/device_local_account_policy_provider.h"
 #include "chrome/browser/chromeos/policy/login_profile_policy_provider.h"
 #include "components/user_manager/user.h"
 #include "components/user_manager/user_manager.h"
 #endif
 
@@ skipping 91 matching lines @@
   policy_service_.reset(new PolicyServiceImpl(providers));
 
 #if defined(OS_CHROMEOS)
   if (is_primary_user_) {
     if (user_cloud_policy_manager)
       connector->SetUserPolicyDelegate(user_cloud_policy_manager);
     else if (special_user_policy_provider_)
       connector->SetUserPolicyDelegate(special_user_policy_provider_.get());
   }
 #endif
+
+#if defined(OS_WIN) || defined(OS_MACOSX)
+  EnableNPAPIIfRequired();
+#endif
 }
 
+#if defined(OS_WIN) || defined(OS_MACOSX)
+void ProfilePolicyConnector::EnableNPAPIIfRequired() {

[Mattias Nissler (ping if slow), 2015/04/09 17:15:01]

The canonical way to do this within the policy/prefs framework: You'd have a
policy handler that looks at the policy keys you care about (i.e. the ones
below). You introduce a boolean pref named prefs::kEnableNpapi, which the policy
handler sets to true if any of the policies are set. Then, have some code
register a pref observer on the Profile's PrefService that takes care of making
the appropriate call into content to change the value if appropriate.

+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+
+  if (command_line->HasSwitch(switches::kEnableNpapi))
+    return;
+
+  PolicyNamespace chrome_ns = PolicyNamespace(POLICY_DOMAIN_CHROME, "");
+  const PolicyMap& chrome_policy = policy_service_->GetPolicies(chrome_ns);
+
+  // The list of Plugin related policies that re-enable NPAPI. Remove once NPAPI
+  // is dead.
+  const std::string plugin_policies[] = { key::kEnabledPlugins,
+                                          key::kPluginsAllowedForUrls,
+                                          key::kPluginsBlockedForUrls,
+                                          key::kDisabledPluginsExceptions,
+                                          key::kDisabledPlugins };
+  for (auto policy : plugin_policies) {
+    if (chrome_policy.GetValue(policy)) {
+      content::PluginService::GetInstance()->EnableNpapiPlugins();
+      break;
+    }
+  }
+}
+#endif
+
 void ProfilePolicyConnector::InitForTesting(scoped_ptr<PolicyService> service) {
   policy_service_ = service.Pass();
 }
 
 void ProfilePolicyConnector::Shutdown() {
 #if defined(OS_CHROMEOS)
   BrowserPolicyConnectorChromeOS* connector =
       g_browser_process->platform_part()->browser_policy_connector_chromeos();
   if (is_primary_user_)
     connector->SetUserPolicyDelegate(NULL);
@@ skipping 32 matching lines @@
   BrowserPolicyConnectorChromeOS* connector =
       g_browser_process->platform_part()->browser_policy_connector_chromeos();
   if (HasChromePolicy(connector->GetDeviceCloudPolicyManager(), name))
     return false;
 #endif
 
   return true;
 }
 
 }  // namespace policy