diff -r 000000000000 -r 6474c204b198 toolkit/crashreporter/client/crashreporter_unix_common.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/crashreporter/client/crashreporter_unix_common.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,69 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "crashreporter.h"
+
+#include <dirent.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <algorithm>
+
+using namespace CrashReporter;
+using std::string;
+using std::vector;
+using std::sort;
+
+struct FileData
+{
+  time_t timestamp;
+  string path;
+};
+
+static bool CompareFDTime(const FileData& fd1, const FileData& fd2)
+{
+  return fd1.timestamp > fd2.timestamp;
+}
+
+void UIPruneSavedDumps(const std::string& directory)
+{
+  DIR *dirfd = opendir(directory.c_str());
+  if (!dirfd)
+    return;
+
+  vector<FileData> dumpfiles;
+
+  while (dirent *dir = readdir(dirfd)) {
+    FileData fd;
+    fd.path = directory + '/' + dir->d_name;
+    if (fd.path.size() < 5)
+      continue;
+
+    if (fd.path.compare(fd.path.size() - 4, 4, ".dmp") != 0)
+      continue;
+
+    struct stat st;
+    if (stat(fd.path.c_str(), &st)) {
+      closedir(dirfd);
+      return;
+    }
+
+    fd.timestamp = st.st_mtime;
+
+    dumpfiles.push_back(fd);
+  }
+
+  sort(dumpfiles.begin(), dumpfiles.end(), CompareFDTime);
+
+  while (dumpfiles.size() > kSaveCount) {
+    // get the path of the oldest file
+    string path = dumpfiles[dumpfiles.size() - 1].path;
+    UIDeleteFile(path.c_str());
+
+    // s/.dmp/.extra/
+    path.replace(path.size() - 4, 4, ".extra");
+    UIDeleteFile(path.c_str());
+
+    dumpfiles.pop_back();
+  }
+}