No longer keep a lingering reference to TypedUrlDataTypeController after PSS exits

chrome/browser/sync/glue/data_type_controller.h

Index: chrome/browser/sync/glue/data_type_controller.h
diff --git a/chrome/browser/sync/glue/data_type_controller.h b/chrome/browser/sync/glue/data_type_controller.h
index 2be6064ca679a53be1a74fa74cfbb6175d7efd62..f7a97933aeaad4b0c6573d5543fba868415c85aa 100644
--- a/chrome/browser/sync/glue/data_type_controller.h
+++ b/chrome/browser/sync/glue/data_type_controller.h
@@ -22,11 +22,25 @@ class SyncError;
 
 namespace browser_sync {
 
+// The last reference to a DataTypeController should always be released on the
+// UI thread. This is enforced in NonFrontendDataTypeController by blocking
+// until StopAssociation() has finished executing.
+struct ForceDeleteOnUIThread {
+  template<typename T>
+  static void Destruct(const T* x) {
+    if (content::BrowserThread::CurrentlyOn(content::BrowserThread::UI)) {
+      delete x;
+    } else {
+      NOTREACHED();
+    }
+  }
+};
+
 // Data type controllers need to be refcounted threadsafe, as they may
 // need to run model associator or change processor on other threads.
 class DataTypeController
     : public base::RefCountedThreadSafe<
-          DataTypeController, content::BrowserThread::DeleteOnUIThread>,
+          DataTypeController, ForceDeleteOnUIThread>,
       public DataTypeErrorHandler {
  public:
   enum State {
@@ -105,8 +119,7 @@ class DataTypeController
       syncable::ModelType type) OVERRIDE;
 
  protected:
-  friend struct content::BrowserThread::DeleteOnThread<
-      content::BrowserThread::UI>;
+  friend struct ForceDeleteOnUIThread;
   friend class base::DeleteHelper<DataTypeController>;
 
   virtual ~DataTypeController() {}