Benchmark tools: Android memtrack_helper meaningful errors.

tools/android/memtrack_helper/memtrack_helper.h

Index: tools/android/memtrack_helper/memtrack_helper.h
diff --git a/tools/android/memtrack_helper/memtrack_helper.h b/tools/android/memtrack_helper/memtrack_helper.h
index b7cbf39564e672515557319dbc60af187e92c619..df349c3c3ed6e9e05a5ee6d6c66d3d2f24480502 100644
--- a/tools/android/memtrack_helper/memtrack_helper.h
+++ b/tools/android/memtrack_helper/memtrack_helper.h
@@ -7,6 +7,7 @@
 #ifndef TOOLS_ANDROID_MEMTRACK_HELPER_H_
 #define TOOLS_ANDROID_MEMTRACK_HELPER_H_
 
+#include <android/log.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -16,6 +17,7 @@
 
 static inline void exit_with_failure(const char* reason) {
   perror(reason);
+  __android_log_write(ANDROID_LOG_ERROR, "memtrack_helper", reason);
   exit(EXIT_FAILURE);
 }