SyzyASAN: Block for crash handler startup as temporary workaround for startup hang

chrome/app/chrome_exe_main_win.cc

Index: chrome/app/chrome_exe_main_win.cc
diff --git a/chrome/app/chrome_exe_main_win.cc b/chrome/app/chrome_exe_main_win.cc
index c30545379b81783bc954d3472421b7c7dbfe76bb..b95c04a86bc1cc92a980314c120aad0862ba6d00 100644
--- a/chrome/app/chrome_exe_main_win.cc
+++ b/chrome/app/chrome_exe_main_win.cc
@@ -198,6 +198,11 @@ bool RemoveAppCompatFlagsEntry() {
 
 }  // namespace
 
+#if defined(SYZYASAN)
+// This is in chrome_elf.
+extern "C" void BlockUntilHandlerStartedImpl();
+#endif  // SYZYASAN
+
 #if !defined(WIN_CONSOLE_APP)
 int APIENTRY wWinMain(HINSTANCE instance, HINSTANCE prev, wchar_t*, int) {
 #else
@@ -232,6 +237,14 @@ int main() {
   // Signal Chrome Elf that Chrome has begun to start.
   SignalChromeElf();
 
+#if defined(SYZYASAN)
+  if (process_type.empty()) {
+    // This is a temporary workaround for a race during startup with the
+    // syzyasan_rtl.dll. See https://crbug.com/675710.
+    BlockUntilHandlerStartedImpl();
+  }
+#endif  // SYZYASAN
+
   // The exit manager is in charge of calling the dtors of singletons.
   base::AtExitManager exit_manager;