Switch //components away from base::ListValue::Append(Value*) overload.

components/sync/syncable/entry_kernel.h

Index: components/sync/syncable/entry_kernel.h
diff --git a/components/sync/syncable/entry_kernel.h b/components/sync/syncable/entry_kernel.h
index 03a2ff1e8a16206a1d005b773ca515fcbd5a6d73..fb4208aec76bbfe46efef816088b3c4b4000498a 100644
--- a/components/sync/syncable/entry_kernel.h
+++ b/components/sync/syncable/entry_kernel.h
@@ -400,12 +400,10 @@ typedef std::map<int64_t, EntryKernelMutation> EntryKernelMutationMap;
 
 typedef Immutable<EntryKernelMutationMap> ImmutableEntryKernelMutationMap;
 
-// Caller owns the return value.
-base::DictionaryValue* EntryKernelMutationToValue(
+std::unique_ptr<base::DictionaryValue> EntryKernelMutationToValue(
     const EntryKernelMutation& mutation);
 
-// Caller owns the return value.
-base::ListValue* EntryKernelMutationMapToValue(
+std::unique_ptr<base::ListValue> EntryKernelMutationMapToValue(
     const EntryKernelMutationMap& mutations);
 
 std::ostream& operator<<(std::ostream& os, const EntryKernel& entry_kernel);