Eliminate use of 'delete self' pattern in AttachmentUploaderImpl.

sync/internal_api/public/attachments/attachment_uploader_impl.h

Index: sync/internal_api/public/attachments/attachment_uploader_impl.h
diff --git a/sync/internal_api/public/attachments/attachment_uploader_impl.h b/sync/internal_api/public/attachments/attachment_uploader_impl.h
index 73417694525421051d0cc1985852613fddab35c1..a88c96750894992a08342ce602dd963d41194b7a 100644
--- a/sync/internal_api/public/attachments/attachment_uploader_impl.h
+++ b/sync/internal_api/public/attachments/attachment_uploader_impl.h
@@ -55,7 +55,7 @@ class SYNC_EXPORT AttachmentUploaderImpl : public AttachmentUploader,
   typedef std::string UniqueId;
   typedef base::ScopedPtrHashMap<UniqueId, UploadState> StateMap;
 
-  void DeleteUploadStateFor(const UniqueId& unique_id);
+  void OnUploadStateStopped(const UniqueId& unique_id);
 
   GURL sync_service_url_;
   scoped_refptr<net::URLRequestContextGetter> url_request_context_getter_;
@@ -64,6 +64,10 @@ class SYNC_EXPORT AttachmentUploaderImpl : public AttachmentUploader,
   scoped_refptr<OAuth2TokenServiceRequest::TokenServiceProvider>
       token_service_provider_;
   StateMap state_map_;
+
+  // Must be last data member.
+  base::WeakPtrFactory<AttachmentUploaderImpl> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(AttachmentUploaderImpl);
 };