Enable size_t to int truncation warnings in PPAPI

ppapi/proxy/ppp_printing_proxy.cc

 // Copyright (c) 2012 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/proxy/ppp_printing_proxy.h"
 
 #include <string.h>
 
+#include "base/numerics/safe_conversions.h"
 #include "ppapi/c/dev/ppp_printing_dev.h"
 #include "ppapi/proxy/host_dispatcher.h"
 #include "ppapi/proxy/plugin_dispatcher.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/shared_impl/ppapi_globals.h"
 #include "ppapi/shared_impl/proxy_lock.h"
 #include "ppapi/shared_impl/resource_tracker.h"
 
 namespace ppapi {
 namespace proxy {
@@ skipping 154 matching lines @@
 
 void PPP_Printing_Proxy::OnPluginMsgPrintPages(
     PP_Instance instance,
     const std::vector<PP_PrintPageNumberRange_Dev>& pages,
     HostResource* result) {
   if (!ppp_printing_impl_ || pages.empty())
     return;
 
   PP_Resource plugin_resource = CallWhileUnlocked(
       ppp_printing_impl_->PrintPages,
-      instance, &pages[0], pages.size());
+      instance, &pages[0], base::checked_cast<uint32_t>(pages.size()));
   ResourceTracker* resource_tracker = PpapiGlobals::Get()->GetResourceTracker();
   Resource* resource_object = resource_tracker->GetResource(plugin_resource);
   if (!resource_object)
     return;
 
   *result = resource_object->host_resource();
 
   // See PrintPages above for how refcounting works.
   resource_tracker->ReleaseResourceSoon(plugin_resource);
 }
 
 void PPP_Printing_Proxy::OnPluginMsgEnd(PP_Instance instance) {
   if (ppp_printing_impl_)
     CallWhileUnlocked(ppp_printing_impl_->End, instance);
 }
 
 void PPP_Printing_Proxy::OnPluginMsgIsScalingDisabled(PP_Instance instance,
                                                       bool* result) {
   if (ppp_printing_impl_) {
     *result = PP_ToBool(CallWhileUnlocked(ppp_printing_impl_->IsScalingDisabled,
                                           instance));
   } else {
     *result = false;
   }
 }
 
 }  // namespace proxy
 }  // namespace ppapi