Introduce PPB_Flash_Font.

ppapi/proxy/ppb_pdf_proxy.cc

Index: ppapi/proxy/ppb_pdf_proxy.cc
diff --git a/ppapi/proxy/ppb_pdf_proxy.cc b/ppapi/proxy/ppb_pdf_proxy.cc
index aee308f38a885ae8539ee9b206346adf5c55aa9a..d891a11d58a5d9dcc2376853148c3723e1add47a 100644
--- a/ppapi/proxy/ppb_pdf_proxy.cc
+++ b/ppapi/proxy/ppb_pdf_proxy.cc
@@ -15,6 +15,7 @@
 #include "ppapi/proxy/plugin_dispatcher.h"
 #include "ppapi/proxy/plugin_resource_tracker.h"
 #include "ppapi/proxy/ppapi_messages.h"
+#include "ppapi/shared_impl/proxy_lock.h"
 #include "ppapi/thunk/enter.h"
 #include "ppapi/thunk/ppb_pdf_api.h"
 
@@ -67,6 +68,8 @@ PP_Resource GetFontFileWithFallback(
     PP_Instance instance,
     const PP_FontDescription_Dev* description,
     PP_PrivateFontCharset charset) {
+  ProxyAutoLock lock;
+
   PluginDispatcher* dispatcher = PluginDispatcher::GetForInstance(instance);
   if (!dispatcher)
     return 0;