Chrome Cleaner test child process logger: add end of logs statement

The logging was a bit confusing if there were no child process logs.
This makes things a bit clearer.

Bug: 1030333
Change-Id: I26f0fdc47686ce1b79a2c85e8f3a9bc0bab07567
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1955036Reviewed-by: Joe Mason <joenotcharles@chromium.org>
Commit-Queue: proberge <proberge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#722983}

chrome/chrome_cleaner/test/child_process_logger.cc

@@ -81,10 +81,16 @@ void ChildProcessLogger::DumpLogs() const {
   std::vector<base::StringPiece> lines =
       base::SplitStringPiece(log_file_contents, "\n", base::TRIM_WHITESPACE,
                              base::SPLIT_WANT_NONEMPTY);
+  if (lines.empty()) {
+    LOG(ERROR) << "Child process log file is empty";
+    return;
+  }
+
   LOG(ERROR) << "Dumping child process logs";
   for (const auto& line : lines) {
     LOG(ERROR) << "Child process: " << line;
   }
+  LOG(ERROR) << "Finished dumping child process logs";
 }
 
 }  // namespace chrome_cleaner