Use the WebKit default fonts when specifying generic font families.

webkit/plugins/ppapi/webkit_forwarding_impl.h

 // 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 "ppapi/shared_impl/webkit_forwarding.h"
 
 #include "base/compiler_specific.h"
 
+namespace ppapi {
+struct Preferences;
+}
+
 namespace webkit {
 namespace ppapi {
 
 class WebKitForwardingImpl : public ::ppapi::WebKitForwarding {
  public:
   WebKitForwardingImpl();
   virtual ~WebKitForwardingImpl();
 
   virtual void CreateFontForwarding(base::WaitableEvent* event,
                                     const PP_FontDescription_Dev& desc,
                                     const std::string& desc_face,
+                                    const ::ppapi::Preferences& prefs,
                                     Font** result) OVERRIDE;
 };
 
 }  // namespace ppapi
 }  // namespace webkit