Reduce resource leak code for StartNaClExecution.

components/nacl/loader/nacl_listener.cc

Index: components/nacl/loader/nacl_listener.cc
diff --git a/components/nacl/loader/nacl_listener.cc b/components/nacl/loader/nacl_listener.cc
index a451895fdd2f88da40c295de531cef1657a2538d..36412af3dc826fedd6e3ff9368fb101b0690f9fd 100644
--- a/components/nacl/loader/nacl_listener.cc
+++ b/components/nacl/loader/nacl_listener.cc
@@ -336,10 +336,23 @@ void NaClListener::OnStart(const nacl::NaClStartParams& params) {
   }
   NaClChromeMainSetUrandomFd(urandom_fd);
 #endif
+
+  // Before starting the launching process, verify if FDs/HANDLEs are properly
+  // transferred to here.
+  // These can be stale, if some unexpected error happens in the sender
+  // process. It sends the IPC message regardless of the errors with deferring
+  // the error handle to the callee for releasing FDs/HANDLEs properly.
+  CHECK(params.nexe_file != IPC::InvalidPlatformFileForTransit());
+  CHECK(params.imc_bootstrap_handle != IPC::InvalidPlatformFileForTransit());
+  CHECK(params.irt_handle != IPC::InvalidPlatformFileForTransit());
+#if defined(OS_MACOSX)
+  CHECK(params.mac_shm_fd != IPC::InvalidPlatformFileForTransit());
+#endif
+  CHECK(base::SharedMemory::IsHandleValid(params.crash_info_shmem_handle));
+
   struct NaClApp* nap = NULL;
   NaClChromeMainInit();
 
-  CHECK(base::SharedMemory::IsHandleValid(params.crash_info_shmem_handle));
   crash_info_shmem_.reset(new base::SharedMemory(
       params.crash_info_shmem_handle, false /* not readonly */));
   CHECK(crash_info_shmem_->Map(nacl::kNaClCrashInfoShmemSize));
@@ -402,13 +415,11 @@ void NaClListener::OnStart(const nacl::NaClStartParams& params) {
   args->number_of_cores = number_of_cores_;
   args->create_memory_object_func = CreateMemoryObject;
 # if defined(OS_MACOSX)
-  CHECK(params.mac_shm_fd != IPC::InvalidPlatformFileForTransit());
   g_shm_fd = IPC::PlatformFileForTransitToPlatformFile(params.mac_shm_fd);
 # endif
 #endif
 
   DCHECK(params.process_type != nacl::kUnknownNaClProcessType);
-  CHECK(params.irt_handle != IPC::InvalidPlatformFileForTransit());
   NaClHandle irt_handle =
       IPC::PlatformFileForTransitToPlatformFile(params.irt_handle);
 
@@ -432,7 +443,6 @@ void NaClListener::OnStart(const nacl::NaClStartParams& params) {
         params.version);
   }
 
-  CHECK(params.imc_bootstrap_handle != IPC::InvalidPlatformFileForTransit());
   args->imc_bootstrap_handle =
       IPC::PlatformFileForTransitToPlatformFile(params.imc_bootstrap_handle);
   args->enable_debug_stub = params.enable_debug_stub;