Add additional error logging to investigate Autocomplete Sync failures.

chrome/browser/sync/profile_sync_service_preference_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 <map>
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
@@ skipping 57 matching lines @@
       return sync_api::kInvalidId;
     }
 
     sync_api::WriteNode tag_node(&trans);
     sync_api::WriteNode node(&trans);
 
     if (tag_node.InitByClientTagLookup(syncable::PREFERENCES, name) ==
             sync_api::BaseNode::INIT_OK) {
       return WriteSyncedValue(name, value, &tag_node);
     }
-    if (node.InitUniqueByCreation(syncable::PREFERENCES, root, name))
+
+    sync_api::WriteNode::InitUniqueByCreationResult result =
+        node.InitUniqueByCreation(syncable::PREFERENCES, root, name);
+    if (result == sync_api::WriteNode::INIT_SUCCESS)
       return WriteSyncedValue(name, value, &node);
 
     return sync_api::kInvalidId;
   }
 
  protected:
   ProfileSyncServicePreferenceTest()
       : example_url0_("http://example.com/0"),
         example_url1_("http://example.com/1"),
         example_url2_("http://example.com/2"),
@@ skipping 483 matching lines @@
   EXPECT_FALSE(pref->IsDefaultValue());
   // There should be no synced value.
   EXPECT_TRUE(GetSyncedValue(prefs::kHomePage) == NULL);
   // Switch kHomePage back to unmanaged.
   profile_->GetTestingPrefService()->RemoveManagedPref(prefs::kHomePage);
   // The original value should be picked up.
   EXPECT_TRUE(pref->IsDefaultValue());
   // There should still be no synced value.
   EXPECT_TRUE(GetSyncedValue(prefs::kHomePage) == NULL);
 }