Adds a pref and a policy to decide if PDFs should always be opened externally.

chrome/browser/policy/configuration_policy_handler_list_factory.cc

 // Copyright 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/configuration_policy_handler_list_factory.h"
 
 #include <limits.h>
 #include <stddef.h>
 
 #include <utility>
@@ skipping 128 matching lines @@
     base::Value::TYPE_STRING },
   { key::kDisabledPlugins,
     prefs::kPluginsDisabledPlugins,
     base::Value::TYPE_LIST },
   { key::kDisabledPluginsExceptions,
     prefs::kPluginsDisabledPluginsExceptions,
     base::Value::TYPE_LIST },
   { key::kEnabledPlugins,
     prefs::kPluginsEnabledPlugins,
     base::Value::TYPE_LIST },
+  { key::kAlwaysOpenPdfExternally,
+    prefs::kPluginsAlwaysOpenPdfExternally,
+    base::Value::TYPE_BOOLEAN },
   { key::kShowHomeButton,
     prefs::kShowHomeButton,
     base::Value::TYPE_BOOLEAN },
   { key::kSavingBrowserHistoryDisabled,
     prefs::kSavingBrowserHistoryDisabled,
     base::Value::TYPE_BOOLEAN },
   { key::kAllowDeletingBrowserHistory,
     prefs::kAllowDeletingBrowserHistory,
     base::Value::TYPE_BOOLEAN },
   { key::kDeveloperToolsDisabled,
@@ skipping 722 matching lines @@
       SimpleSchemaValidatingPolicyHandler::MANDATORY_PROHIBITED)));
   handlers->AddHandler(
       base::MakeUnique<chromeos::KeyPermissionsPolicyHandler>(chrome_schema));
   handlers->AddHandler(base::WrapUnique(new DefaultGeolocationPolicyHandler()));
 #endif  // defined(OS_CHROMEOS)
 
   return handlers;
 }
 
 }  // namespace policy