base/prefs: Break the dependency on chrome/common/pref_names.h

BUG=155525
TEST=unit_tests
[email protected]

Review URL: https://codereview.chromium.org/11414133

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@169310 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/base/prefs/json_pref_store_unittest.cc b/base/prefs/json_pref_store_unittest.cc
index c596a6b..5eac326bf 100644
--- a/base/prefs/json_pref_store_unittest.cc
+++ b/base/prefs/json_pref_store_unittest.cc
@@ -15,12 +15,13 @@
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/common/chrome_paths.h"
-#include "chrome/common/pref_names.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 
+const char kHomePage[] = "homepage";
+
 class MockPrefStoreObserver : public PrefStore::Observer {
  public:
   MOCK_METHOD1(OnPrefValueChanged, void (const std::string&));
@@ -96,7 +97,7 @@
   std::string cnn("http://www.cnn.com");
 
   const Value* actual;
-  EXPECT_TRUE(pref_store->GetValue(prefs::kHomePage, &actual));
+  EXPECT_TRUE(pref_store->GetValue(kHomePage, &actual));
   std::string string_value;
   EXPECT_TRUE(actual->GetAsString(&string_value));
   EXPECT_EQ(cnn, string_value);