Added code for renderer to cleanly exit.

base/process_util.h

Index: base/process_util.h
diff --git a/base/process_util.h b/base/process_util.h
index a89d4b11c6d0a86ac7646003e46f9eb74ec4abe7..90faab1939ee2baa3e7b9ab20e760b1630c3ff36 100644
--- a/base/process_util.h
+++ b/base/process_util.h
@@ -10,6 +10,9 @@
 #pragma once
 
 #include "base/basictypes.h"
+#if defined(RENDERER_CLEAN_EXIT)
+#include "base/atomicops.h"
+#endif // defined(RENDERER_CLEAN_EXIT)
 
 #if defined(OS_WIN)
 #include <windows.h>
@@ -839,6 +842,12 @@ BASE_EXPORT void RaiseProcessToHighPriority();
 void RestoreDefaultExceptionHandler();
 #endif  // defined(OS_MACOSX)
 
+#if defined(RENDERER_CLEAN_EXIT)
+extern base::subtle::Atomic32 exit_counter;
+
+BASE_EXPORT void clean_exit(int return_value) __attribute__((noreturn));
+#endif // defined(RENDERER_CLEAN_EXIT)
+
 }  // namespace base
 
 #endif  // BASE_PROCESS_UTIL_H_