Move UI dependency from WebDataService to WebDataServiceFactory.

chrome/browser/api/webdata/web_data_service_base.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_API_WEBDATA_WEB_DATA_SERVICE_BASE_H_
 #define CHROME_BROWSER_API_WEBDATA_WEB_DATA_SERVICE_BASE_H_
 
+#include "base/callback_forward.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_source.h"
 #include "sql/init_status.h"
 
 class WebDatabase;
 class WebDatabaseService;
 
 namespace base {
 class Thread;
 }
 
 // Base for WebDataService class hierarchy.
 class WebDataServiceBase
     : public base::RefCountedThreadSafe<WebDataServiceBase,
           content::BrowserThread::DeleteOnUIThread> {
  public:
   // All requests return an opaque handle of the following type.
   typedef int Handle;
 
-  WebDataServiceBase();
+  // Users of this class may provide a callback to handle errors
+  // (e.g. by showing a UI). The callback is called only on error, and
+  // takes a single parameter, the sql::InitStatus value from trying
+  // to open the database.
+  typedef base::Callback<void(sql::InitStatus)> ProfileErrorCallback;

[Cait (Slow), 2013/03/18 16:16:37]

ATM we have a WebDataServiceBase::ProfileErrorCallback and a
WebDatabaseService::InitCallback type which are defined identically. We should
probably merge them and name them something more general, but I think this can
wait for a later CL. 

[Jói, 2013/03/18 23:21:23]

Yes, I think we should wait for all the pieces to fall in place before deciding
whether to combine them. I've added a TODO here.

+
+  // |callback| will only be invoked on error, and only if
+  // ||callback.is_null()| evaluates to true.

[Cait (Slow), 2013/03/18 16:16:37]

nit: |callback.is_null() --> !callback.is_null()

[Jói, 2013/03/18 23:21:23]

Thanks for the catch. Switched "evaluates to true" to "evaluates to false"
instead.

+  WebDataServiceBase(const ProfileErrorCallback& callback);
 
   // Cancel any pending request. You need to call this method if your
   // WebDataServiceConsumer is about to be deleted.
   virtual void CancelRequest(Handle h);
 
   // Returns the notification source for this service. This may use a
   // pointer other than this object's |this| pointer.
   virtual content::NotificationSource GetNotificationSource();
 
   // Shutdown the web data service. The service can no longer be used after this
@@ skipping 26 matching lines @@
   scoped_ptr<WebDatabaseService> wdbs_;
 
   // True if we've received a notification that the WebDatabase has loaded.
   bool db_loaded_;
 
  private:
   friend struct content::BrowserThread::DeleteOnThread<
       content::BrowserThread::UI>;
   friend class base::DeleteHelper<WebDataServiceBase>;
 
+  ProfileErrorCallback profile_error_callback_;
+
   void DBInitFailed(sql::InitStatus sql_status);
   void NotifyDatabaseLoadedOnUIThread();
   void DatabaseInitOnDB(sql::InitStatus status);
 };
 
 #endif  // CHROME_BROWSER_API_WEBDATA_WEB_DATA_SERVICE_BASE_H_