Make net/test/test_server correctly report timeouts.

net/test/local_test_server_posix.cc

Index: net/test/local_test_server_posix.cc
diff --git a/net/test/local_test_server_posix.cc b/net/test/local_test_server_posix.cc
index eda65fda605ab3446ffb9586a0356d2a6d7fc1a0..760a915843e0ce812a34bfc2d48add998d81c16b 100644
--- a/net/test/local_test_server_posix.cc
+++ b/net/test/local_test_server_posix.cc
@@ -70,8 +70,12 @@ bool ReadData(int fd, ssize_t bytes_max, uint8* buffer,
 
     int rv = HANDLE_EINTR(poll(poll_fds, 1,
                                remaining_time->InMilliseconds()));
-    if (rv != 1) {
-      PLOG(ERROR) << "poll() failed for child file descriptor";
+    if (rv == 0) {
+      LOG(ERROR) << "poll() timed out; bytes_read=" << bytes_read;
+      return false;
+    } else if (rv < 0) {
+      PLOG(ERROR) << "poll() failed for child file descriptor; bytes_read="
+                  << bytes_read;
       return false;
     }