Remove stl_util from sync.

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 fb4208aec76bbfe46efef816088b3c4b4000498a..82a58988864e4be3788ef8c9e71a3a41fd65686a 100644
--- a/components/sync/syncable/entry_kernel.h
+++ b/components/sync/syncable/entry_kernel.h
@@ -382,16 +382,23 @@ struct EntryKernel {
   bool dirty_;
 };
 
+template <typename T>
 class EntryKernelLessByMetaHandle {
  public:
-  inline bool operator()(const EntryKernel* a, const EntryKernel* b) const {
+  inline bool operator()(T a, T b) const {
     return a->ref(META_HANDLE) < b->ref(META_HANDLE);
   }
 };
 
-typedef std::set<const EntryKernel*, EntryKernelLessByMetaHandle>
+typedef std::set<const EntryKernel*,
+                 EntryKernelLessByMetaHandle<const EntryKernel*>>
     EntryKernelSet;
 
+typedef std::set<
+    std::unique_ptr<EntryKernel>,
+    EntryKernelLessByMetaHandle<const std::unique_ptr<EntryKernel>&>>
+    OwnedEntryKernelSet;
+
 struct EntryKernelMutation {
   EntryKernel original, mutated;
 };