Enable size_t to int truncation warnings in PPAPI

ppapi/cpp/dev/scriptable_object_deprecated.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 "ppapi/cpp/dev/scriptable_object_deprecated.h"
 #include "ppapi/c/dev/ppb_memory_dev.h"
 #include "ppapi/c/dev/ppp_class_deprecated.h"
 #include "ppapi/cpp/module.h"
 #include "ppapi/cpp/var.h"
 
@@ skipping 55 matching lines @@
                          PP_Var* exception) {
   ExceptionConverter e(exception);
   std::vector<Var> props;
   static_cast<ScriptableObject*>(object)->GetAllPropertyNames(&props, e.Get());
   if (props.empty())
     return;
   *property_count = static_cast<uint32_t>(props.size());
 
   const PPB_Memory_Dev* memory_if = static_cast<const PPB_Memory_Dev*>(
       pp::Module::Get()->GetBrowserInterface(PPB_MEMORY_DEV_INTERFACE));
-  *properties = static_cast<PP_Var*>(
-      memory_if->MemAlloc(sizeof(PP_Var) * props.size()));
+  *properties = static_cast<PP_Var*>(memory_if->MemAlloc(
+      static_cast<uint32_t>(sizeof(PP_Var) * props.size())));
 
   for (size_t i = 0; i < props.size(); ++i)
     (*properties)[i] = props[i].Detach();
 }
 
 void SetProperty(void* object,
                  PP_Var name,
                  PP_Var value,
                  PP_Var* exception) {
   ExceptionConverter e(exception);
@@ skipping 95 matching lines @@
 }
 
 // static
 const PPP_Class_Deprecated* ScriptableObject::GetClass() {
   return &plugin_class;
 }
 
 }  // namespace deprecated
 
 }  // namespace pp