Ignore invalid managed user settings values gracefully.

chrome/browser/supervised_user/supervised_user_settings_service.cc

Index: chrome/browser/supervised_user/supervised_user_settings_service.cc
diff --git a/chrome/browser/supervised_user/supervised_user_settings_service.cc b/chrome/browser/supervised_user/supervised_user_settings_service.cc
index 6628c217b971eae0cc53a31dfcc1dc00efbd5a72..20bd2b174781162404dba78c60447b34c58f0628 100644
--- a/chrome/browser/supervised_user/supervised_user_settings_service.cc
+++ b/chrome/browser/supervised_user/supervised_user_settings_service.cc
@@ -241,6 +241,12 @@ SyncMergeResult SupervisedUserSettingsService::MergeDataAndStartSyncing(
         sync_data.GetSpecifics().managed_user_setting();
     std::unique_ptr<base::Value> value =
         JSONReader::Read(supervised_user_setting.value());
+    if (!value) {
+      LOG(ERROR) << "Invalid managed user setting value:"

[Marc Treib, 2016/08/03 14:40:32]

DLOG please, so the message won't make it into release builds.

[Marc Treib, 2016/08/03 14:40:32]

nit: Space after : please

[mamir, 2016/08/03 15:19:36]

Done.

[mamir, 2016/08/03 15:19:36]

Done.

+                 << supervised_user_setting.value()
+                 << ".  Values must be JSON values.";
+      continue;

[Bernhard Bauer, 2016/08/03 14:44:07]

Note that even if we compile out the log, we will still handle this in a Release
build. Now, that is what we want (because it's preferable over crashing), but it
might still be worth to add a comment here to explain that.

[mamir, 2016/08/03 15:19:36]

Done.

+    }
     std::string name_suffix = supervised_user_setting.name();
     std::string name_key = name_suffix;
     base::DictionaryValue* dict = GetDictionaryAndSplitKey(&name_suffix);