RefCounted types should not have public destructors

content/common/gpu/sync_point_manager.h

Index: content/common/gpu/sync_point_manager.h
diff --git a/content/common/gpu/sync_point_manager.h b/content/common/gpu/sync_point_manager.h
index 589aace0fe0da7501c3e6be4766bc07d17da1ccf..dd90cd2065f9cdbac7938d0bc7f992b9edef5dbb 100644
--- a/content/common/gpu/sync_point_manager.h
+++ b/content/common/gpu/sync_point_manager.h
@@ -16,8 +16,7 @@
 
 // This class manages the sync points, which allow cross-channel
 // synchronization.
-class SyncPointManager : public base::RefCountedThreadSafe<SyncPointManager>,
-                         public base::ThreadChecker {
+class SyncPointManager : public base::RefCountedThreadSafe<SyncPointManager> {
  public:
   SyncPointManager();
 
@@ -42,6 +41,8 @@ class SyncPointManager : public base::RefCountedThreadSafe<SyncPointManager>,
 
   ~SyncPointManager();
 
+  base::ThreadChecker thread_checker_;
+
   // Protects the 2 fields below. Note: callbacks shouldn't be called with this
   // held.
   base::Lock lock_;