Add async trace events to trace progress of IPC messages

chrome/nacl/nacl_ipc_adapter_unittest.cc

Index: chrome/nacl/nacl_ipc_adapter_unittest.cc
diff --git a/chrome/nacl/nacl_ipc_adapter_unittest.cc b/chrome/nacl/nacl_ipc_adapter_unittest.cc
index 7f3c55a92f5c223c52f64a53d708a84ac520fcdf..3c64ece9cc631db3864a1374c9c9cef4583690b8 100644
--- a/chrome/nacl/nacl_ipc_adapter_unittest.cc
+++ b/chrome/nacl/nacl_ipc_adapter_unittest.cc
@@ -74,6 +74,7 @@ TEST_F(NaClIPCAdapterTest, SimpleReceiveRewriting) {
   int routing_id = 0x89898989;
   uint32 type = 0x55555555;
   IPC::Message input(routing_id, type, IPC::Message::PRIORITY_NORMAL);
+  uint32 flags = input.flags();
 
   int value = 0x12345678;
   input.WriteInt(value);
@@ -92,8 +93,7 @@ TEST_F(NaClIPCAdapterTest, SimpleReceiveRewriting) {
   EXPECT_EQ(sizeof(int), output_header->payload_size);
   EXPECT_EQ(routing_id, output_header->routing);
   EXPECT_EQ(type, output_header->type);
-  EXPECT_EQ(static_cast<uint32>(IPC::Message::PRIORITY_NORMAL),
-            output_header->flags);
+  EXPECT_EQ(flags, output_header->flags);
   EXPECT_EQ(0u, output_header->num_fds);
   EXPECT_EQ(0u, output_header->pad);