Simplify libcrash_dumper interface and make window_manager gen crash dumps

src/platform/crash/crash_reporter.cc

Index: src/platform/crash/crash_reporter.cc
diff --git a/src/platform/crash/crash_reporter.cc b/src/platform/crash/crash_reporter.cc
index 3112fd384a6569d0988c2a20007ae49f5320315e..951d3fae3d4ecfc96104f949b1c9cf1d3a19545b 100644
--- a/src/platform/crash/crash_reporter.cc
+++ b/src/platform/crash/crash_reporter.cc
@@ -15,6 +15,7 @@
 #pragma GCC diagnostic ignored "-Wstrict-aliasing"
 DEFINE_bool(init, false, "Initialize crash logging");
 DEFINE_bool(clean_shutdown, false, "Signal clean shutdown");
+DEFINE_bool(crash_test, false, "Crash test");
 DEFINE_string(exec, "", "Executable name crashed");
 DEFINE_int32(pid, -1, "Crashing PID");
 DEFINE_int32(signal, -1, "Signal causing crash");
@@ -113,6 +114,13 @@ int main(int argc, char *argv[]) {
   CHECK(FLAGS_pid != -1) << "PID must be set";
   CHECK(FLAGS_exec != "") << "Executable name must be set";
 
+  // Make it possible to test what happens when we crash while
+  // handling a crash.
+  if (FLAGS_crash_test) {
+    *(char *)0 = 0;
+    return 0;
+  }
+
   user_collector.HandleCrash(FLAGS_signal, FLAGS_pid, FLAGS_exec);
 
   return 0;