Fix calling convention mismatch for ::CreateThread callback

ASan intercepts CreateThread, and if the calling convention is wrong,
ESP will end up off by 4, leading to a wild return.

A classic mistake that Microsoft appears to tolerate sometimes:
https://blogs.msdn.microsoft.com/oldnewthing/20040115-00/?p=41043

TBR=thakis@chromium.org,liamjm@chromium.org,jschuh@chromium.org

Review URL: https://codereview.chromium.org/1702403002

Cr-Commit-Position: refs/heads/master@{#375920}

1 files changed, 3 insertions, 3 deletions

diff --git a/sandbox/win/src/process_policy_test.cc b/sandbox/win/src/process_policy_test.cc
index e97a16f..8062d46 100644
--- a/sandbox/win/src/process_policy_test.cc
+++ b/sandbox/win/src/process_policy_test.cc
@@ -283,7 +283,7 @@ std::wstring GenerateEventName(DWORD pid) {
 
 // This is the function that is called when testing thread creation.
 // It is expected to set an event that the caller is waiting on.
-DWORD TestThreadFunc(LPVOID lpdwThreadParam) {
+DWORD WINAPI TestThreadFunc(LPVOID lpdwThreadParam) {
   std::wstring event_name = GenerateEventName(
       static_cast<DWORD>(reinterpret_cast<uintptr_t>(lpdwThreadParam)));
   if (!event_name.length()) {
@@ -313,7 +313,7 @@ SBOX_TESTS_COMMAND int Process_CreateThread(int argc, wchar_t** argv) {
 
   DWORD thread_id = 0;
   HANDLE thread = NULL;
-  thread = ::CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)&TestThreadFunc,
+  thread = ::CreateThread(NULL, 0, &TestThreadFunc,
                           reinterpret_cast<LPVOID>(static_cast<uintptr_t>(pid)),
                           0, &thread_id);
 
@@ -501,7 +501,7 @@ TEST(ProcessPolicyTest, TestCreateThreadOutsideSandbox) {
   DWORD thread_id = 0;
   HANDLE thread = NULL;
   thread = TargetCreateThread(
-      ::CreateThread, NULL, 0, (LPTHREAD_START_ROUTINE)&TestThreadFunc,
+      ::CreateThread, NULL, 0, &TestThreadFunc,
       reinterpret_cast<LPVOID>(static_cast<uintptr_t>(pid)), 0, &thread_id);
   EXPECT_NE(static_cast<HANDLE>(NULL), thread);
   EXPECT_EQ(WAIT_OBJECT_0, WaitForSingleObject(thread, INFINITE));