Fix a bug where killing pages doesn't yield a sad-tab

chrome/nacl/nacl_helper_linux.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // A mini-zygote specifically for Native Client.
 
 #include "components/nacl/common/nacl_helper_linux.h"
 
 #include <errno.h>
 #include <fcntl.h>
@@ skipping 146 matching lines @@
     LOG(ERROR) << "Could not read known_dead status";
     return false;
   }
   // TODO(jln): With NaCl, known_dead seems to never be set to true (unless
   // called from the Zygote's kZygoteCommandReap command). This means that we
   // will sometimes detect the process as still running when it's not. Fix
   // this!
 
   int exit_code;
   base::TerminationStatus status;
-  // See the comment in the Zygote about known_dead.
-  if (known_dead) {
-    // Make sure to not perform a blocking wait on something that
-    // could still be alive.
-    if (kill(child_to_wait, SIGKILL)) {
-      PLOG(ERROR) << "kill (" << child_to_wait << ")";
-    }
-    status = base::WaitForTerminationStatus(child_to_wait, &exit_code);
-  } else {
+  if (known_dead)
+    status = base::GetKnownDeadTerminationStatus(child_to_wait, &exit_code);
+  else
     status = base::GetTerminationStatus(child_to_wait, &exit_code);
-  }
   output_pickle->WriteInt(static_cast<int>(status));
   output_pickle->WriteInt(exit_code);
   return true;
 }
 
 // This is a poor man's check on whether we are sandboxed.
 bool IsSandboxed() {
   int proc_fd = open("/proc/self/exe", O_RDONLY);
   if (proc_fd >= 0) {
     HANDLE_EINTR(close(proc_fd));
@@ skipping 197 matching lines @@
   // Now handle requests from the Zygote.
   while (true) {
     bool request_handled = HandleZygoteRequest(kNaClZygoteDescriptor,
                                                system_info);
     // Do not turn this into a CHECK() without thinking about robustness
     // against malicious IPC requests.
     DCHECK(request_handled);
   }
   NOTREACHED();
 }