DPCHECK known conditions when we guess false in CurrentProcessHasOpenDirectories

sandbox/linux/services/credentials.cc

Index: sandbox/linux/services/credentials.cc
diff --git a/sandbox/linux/services/credentials.cc b/sandbox/linux/services/credentials.cc
index cea757c535860c0d1c12d4d7fbb479b848d6bef4..3ce140480f5e590939f953f0b517a3252f5034b4 100644
--- a/sandbox/linux/services/credentials.cc
+++ b/sandbox/linux/services/credentials.cc
@@ -163,9 +163,13 @@ bool Credentials::HasOpenDirectory(int proc_fd) {
   } else {
     proc_self_fd = openat(AT_FDCWD, "/proc/self/fd", O_DIRECTORY | O_RDONLY);
     if (proc_self_fd < 0) {
+      // If this process has been chrooted (eg into /proc/self/fdinfo) then
+      // the new root dir will not have directory listing permissions for us
+      // (hence EACCES).  And if we do have this permission, then /proc won't
+      // exist anyway (hence ENOENT).
+      CHECK(errno == EACCES || errno == ENOENT);

[jln (very slow on Chromium), 2013/11/27 21:26:15]

Do you want to make this a DPCHECK instead?

DCHECK is good enough for this purpose and printing errno will be useful.

[Mostyn Bramley-Moore, 2013/11/28 09:35:32]

Done.

+
       // If not available, guess false.
-      // TODO(mostynb@opera.com): add a CHECK_EQ(ENOENT, errno); Figure out what
-      // other situations are here. http://crbug.com/314985
       return false;
     }
   }