Silence a warning in unit tests

components/policy/core/common/generate_policy_source_unittest.cc

 // Copyright 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.
 
 #include <cstring>
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/values.h"
 #include "build/build_config.h"
 #include "components/policy/core/common/policy_details.h"
 #include "components/policy/core/common/schema.h"
 #include "policy/policy_constants.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 // This unittest tests the code generated by
 // chrome/tools/build/generate_policy_source.py.
 
 namespace policy {
 
 namespace {
 
+#if defined(OS_CHROMEOS)
 // Checks if two schemas are the same or not. Note that this function doesn't
 // consider restrictions on integers and strings nor pattern properties.
 bool IsSameSchema(Schema a, Schema b) {
   if (a.valid() != b.valid())
     return false;
   if (!a.valid())
     return true;
   if (a.type() != b.type())
     return false;
   if (a.type() == base::Value::TYPE_LIST)
     return IsSameSchema(a.GetItems(), b.GetItems());
   if (a.type() != base::Value::TYPE_DICTIONARY)
     return true;
   Schema::Iterator a_it = a.GetPropertiesIterator();
   Schema::Iterator b_it = b.GetPropertiesIterator();
   while (!a_it.IsAtEnd()) {
     if (b_it.IsAtEnd())
       return false;
     if (strcmp(a_it.key(), b_it.key()) != 0)
       return false;
     if (!IsSameSchema(a_it.schema(), b_it.schema()))
       return false;
     a_it.Advance();
     b_it.Advance();
   }
   if (!b_it.IsAtEnd())
     return false;
   return IsSameSchema(a.GetAdditionalProperties(), b.GetAdditionalProperties());
 }
+#endif
 
 }  // namespace
 
 TEST(GeneratePolicySource, ChromeSchemaData) {
   Schema schema = Schema::Wrap(GetChromeSchemaData());
   ASSERT_TRUE(schema.valid());
   EXPECT_EQ(base::Value::TYPE_DICTIONARY, schema.type());
 
   Schema subschema = schema.GetAdditionalProperties();
   EXPECT_FALSE(subschema.valid());
@@ skipping 103 matching lines @@
   EXPECT_TRUE(details->is_device_policy);
   EXPECT_EQ(90, details->id);
   EXPECT_EQ(0u, details->max_external_data_size);
 #endif
 
   // TODO(bartfab): add a test that verifies a max_external_data_size larger
   // than 0, once a type 'external' policy is added.
 }
 
 }  // namespace policy