Enable Clang warnings in implementation files for OS X

chrome/browser/ui/cocoa/autofill/autofill_account_chooser_unittest.mm

 // Copyright (c) 2013 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.
 
 #import "chrome/browser/ui/cocoa/autofill/autofill_account_chooser.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/ui/autofill/mock_autofill_dialog_controller.h"
@@ skipping 30 matching lines @@
   }
 
   virtual bool IsCommandIdEnabled(int command_id) const OVERRIDE {
     return true;
   }
 
   virtual bool GetAcceleratorForCommandId(
         int command_id,
         ui::Accelerator* accelerator) OVERRIDE { return false; }
 
-  virtual void ExecuteCommand(int command_id, int event_flags) {}
+  virtual void ExecuteCommand(int command_id, int event_flags) OVERRIDE {}
 };
 
 }  // namespace
 
 TEST_VIEW(AutofillAccountChooserTest, view_);
 
 // Make sure account chooser has all required subviews
 TEST_F(AutofillAccountChooserTest, SubViews) {
   bool hasIcon = false;
   bool hasLink = false;
@@ skipping 34 matching lines @@
       break;
     }
   }
 
   NSArray* items = [[button attachedMenu] itemArray];
   EXPECT_EQ(3U, [items count]);
   EXPECT_NSEQ(@"", [[items objectAtIndex:0] title]);
   EXPECT_NSEQ(@"one", [[items objectAtIndex:1] title]);
   EXPECT_NSEQ(@"two", [[items objectAtIndex:2] title]);
 }