diff -r 000000000000 -r 6474c204b198 toolkit/crashreporter/test/browser/browser_bug471404.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/crashreporter/test/browser/browser_bug471404.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,67 @@
+function check_clear_visible(tab, aVisible) {
+  let doc = gBrowser.getBrowserForTab(tab).contentDocument;
+  let visible = false;
+  let button = doc.getElementById("clear-reports");
+  if (button) {
+    let style = doc.defaultView.getComputedStyle(button, "");
+    if (style.display != "none" &&
+        style.visibility == "visible")
+      visible = true;
+  }
+  is(visible, aVisible,
+     "clear reports button is " + (aVisible ? "visible" : "hidden"));
+}
+
+// each test here has a setup (run before loading about:crashes) and onload (run after about:crashes loads)
+let _tests = [{setup: null, onload: function(tab) { check_clear_visible(tab, false); }},
+              {setup: function(crD) { add_fake_crashes(crD, 1); },
+               onload: function(tab) { check_clear_visible(tab, true); }}
+              ];
+let _current_test = 0;
+
+function run_test_setup(crD) {
+  if (_tests[_current_test].setup) {
+    _tests[_current_test].setup(crD);
+  }
+}
+
+function run_test_onload(tab) {
+  if (_tests[_current_test].onload) {
+    _tests[_current_test].onload(tab);
+  }
+  _current_test++;
+
+  if (_current_test == _tests.length) {
+    cleanup_fake_appdir();
+    gBrowser.removeTab(tab);
+    finish();
+    return false;
+  }
+  return true;
+}
+
+function test() {
+  waitForExplicitFinish();
+  let appD = make_fake_appdir();
+  let crD = appD.clone();
+  crD.append("Crash Reports");
+
+  let tab = gBrowser.selectedTab = gBrowser.addTab("about:blank");
+  let browser = gBrowser.getBrowserForTab(tab);
+  let onLoad = function () {
+    executeSoon(function() {
+      if (run_test_onload(tab)) {
+        // prep and run the next test
+        run_test_setup(crD);
+        executeSoon(function() { browser.loadURI("about:crashes", null, null); });
+      }
+    });
+  };
+  browser.addEventListener("load", onLoad, true);
+  registerCleanupFunction(function () {
+    browser.removeEventListener("load", onLoad, true);
+  });
+  // kick things off
+  run_test_setup(crD);
+  browser.loadURI("about:crashes", null, null);
+}