[Mac] Add testing code to expose an NSColor memory leak.

chrome/browser/cocoa/autocomplete_text_field_unittest.mm

 // Copyright (c) 2009 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 <Cocoa/Cocoa.h>
 
 #include "base/scoped_nsobject.h"
 #import "chrome/browser/cocoa/autocomplete_text_field.h"
 #import "chrome/browser/cocoa/autocomplete_text_field_cell.h"
 #import "chrome/browser/cocoa/autocomplete_text_field_editor.h"
@@ skipping 67 matching lines @@
 TEST_F(AutocompleteTextFieldTest, Cell) {
   AutocompleteTextFieldCell* cell = [field_ autocompleteTextFieldCell];
   EXPECT_EQ(cell, [field_ cell]);
   EXPECT_TRUE(cell != nil);
 }
 
 // Test drawing, mostly to ensure nothing leaks or crashes.
 TEST_F(AutocompleteTextFieldTest, Display) {
   [field_ display];
 
+  // Test focussed drawing.
+  cocoa_helper_.makeFirstResponder(field_);
+  [field_ display];
+  cocoa_helper_.clearFirstResponder();
+
   // Test display of various cell configurations.
   AutocompleteTextFieldCell* cell = [field_ autocompleteTextFieldCell];
 
   [cell setSearchHintString:@"Type to search"];
   [field_ display];
 
   NSImage* image = [NSImage imageNamed:@"NSApplicationIcon"];
   [cell setKeywordHintPrefix:@"prefix" image:image suffix:@"suffix"];
   [field_ display];
 
@@ skipping 254 matching lines @@
   }
   EXPECT_TRUE(editor_ != nil);
 
   // This needs to be called every time, otherwise notifications
   // aren't sent correctly.
   [editor_ setFieldEditor:YES];
   return editor_;
 }
 
 @end