Small fixes to allow unit tests to compile with gcc 4.7.x (tested with gcc 4.7.2)

chrome/browser/predictors/autocomplete_action_predictor_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/predictors/autocomplete_action_predictor.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/guid.h"
 #include "base/memory/ref_counted.h"
@@ skipping 137 matching lines @@
     row.number_of_misses = test_row.number_of_misses;
     return row;
   }
 
   void AddAllRows() {
     for (size_t i = 0; i < arraysize(test_url_db); ++i)
       AddRow(test_url_db[i]);
   }
 
   std::string AddRow(const TestUrlInfo& test_row) {
-    AutocompleteActionPredictor::DBCacheKey key = { test_row.user_text,
-                                                    test_row.url };
     AutocompleteActionPredictorTable::Row row =
         CreateRowFromTestUrlInfo(test_row);
     predictor_->AddAndUpdateRows(
         AutocompleteActionPredictorTable::Rows(1, row),
         AutocompleteActionPredictorTable::Rows());
 
     return row.id;
   }
 
   void UpdateRow(const AutocompleteActionPredictorTable::Row& row) {
@@ skipping 200 matching lines @@
          AutocompleteActionPredictor::ACTION_PRERENDER) ?
         AutocompleteActionPredictor::ACTION_PRECONNECT :
         test_url_db[i].expected_action;
     EXPECT_EQ(expected_action,
               predictor()->RecommendAction(test_url_db[i].user_text, match))
         << "Unexpected action for " << match.destination_url;
   }
 }
 
 }  // namespace predictors