Enable size_t to int truncation warnings in PPAPI

ppapi/tests/test_memory.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/tests/test_memory.h"
 
 #include "ppapi/c/dev/ppb_memory_dev.h"
 #include "ppapi/cpp/instance.h"
 #include "ppapi/cpp/module.h"
 #include "ppapi/tests/testing_instance.h"
@@ skipping 12 matching lines @@
   return memory_dev_interface_ && CheckTestingInterface();
 }
 
 void TestMemory::RunTests(const std::string& filter) {
   RUN_TEST(MemAlloc, filter);
   RUN_TEST(NullMemFree, filter);
 }
 
 std::string TestMemory::TestMemAlloc() {
   char* buffer = static_cast<char*>(
-      memory_dev_interface_->MemAlloc(kTestBufferSize));
+      memory_dev_interface_->MemAlloc(static_cast<uint32_t>(kTestBufferSize)));
   // Touch a couple of locations.  Failure will crash the test.
   buffer[0] = '1';
   buffer[kTestBufferSize - 1] = '1';
   memory_dev_interface_->MemFree(buffer);
 
   PASS();
 }
 
 std::string TestMemory::TestNullMemFree() {
   // Failure crashes the test.
   memory_dev_interface_->MemFree(NULL);
 
   PASS();
 }