Use the WebKit default fonts when specifying generic font families.

webkit/plugins/ppapi/mock_plugin_delegate.cc

 // 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.
 
 #include "webkit/plugins/ppapi/mock_plugin_delegate.h"
 
 #include "base/message_loop_proxy.h"
 #include "ppapi/c/pp_errors.h"
+#include "ppapi/shared_impl/ppapi_preferences.h"
 
 namespace webkit {
 namespace ppapi {
 
 MockPluginDelegate::MockPluginDelegate() {
 }
 
 MockPluginDelegate::~MockPluginDelegate() {
 }
 
@@ skipping 222 matching lines @@
 
 std::string MockPluginDelegate::GetFlashCommandLineArgs() {
   return std::string();
 }
 
 base::SharedMemory* MockPluginDelegate::CreateAnonymousSharedMemory(
     uint32_t size) {
   return NULL;
 }
 
+::ppapi::Preferences MockPluginDelegate::GetPreferences() {
+  return ::ppapi::Preferences();
+}
+
 }  // namespace ppapi
 }  // namespace webkit