Ensure that SequencedWorkerPools in tests don't outlive their tests

chrome/browser/autocomplete/autocomplete_edit_unittest.cc

Index: chrome/browser/autocomplete/autocomplete_edit_unittest.cc
diff --git a/chrome/browser/autocomplete/autocomplete_edit_unittest.cc b/chrome/browser/autocomplete/autocomplete_edit_unittest.cc
index f52bc4dc193b1ef07f203655d3c230fc396ab283..724f46fdcda4c4f48def550b56545330e22fb31f 100644
--- a/chrome/browser/autocomplete/autocomplete_edit_unittest.cc
+++ b/chrome/browser/autocomplete/autocomplete_edit_unittest.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/message_loop.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/autocomplete/autocomplete_edit.h"
 #include "chrome/browser/ui/omnibox/omnibox_view.h"
@@ -107,10 +108,14 @@ class TestingAutocompleteEditController : public AutocompleteEditController {
 
 }  // namespace
 
-typedef testing::Test AutocompleteEditTest;
+class AutocompleteEditTest : public ::testing::Test {
+ private:
+  // Needed by the blocking pool (but no need to pump it).
+  MessageLoop message_loop_;
+};
 
 // Tests various permutations of AutocompleteModel::AdjustTextForCopy.
-TEST(AutocompleteEditTest, AdjustTextForCopy) {
+TEST_F(AutocompleteEditTest, AdjustTextForCopy) {
   struct Data {
     const char* perm_text;
     const int sel_start;