gdata: Make callback parameter mandatory for GetEntryInfoByPath()

chrome/browser/chromeos/gdata/gdata_file_system.cc

 // 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.
 
 #include "chrome/browser/chromeos/gdata/gdata_file_system.h"
 
 #include <set>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 1852 matching lines @@
       base::Bind(&GDataFileSystem::OnFileDownloaded,
                  ui_weak_ptr_,
                  params),
       params.get_content_callback);
 }
 
 void GDataFileSystem::GetEntryInfoByPath(const FilePath& file_path,
                                          const GetEntryInfoCallback& callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI) ||
          BrowserThread::CurrentlyOn(BrowserThread::IO));
+  DCHECK(!callback.is_null());
+
   RunTaskOnUIThread(
       base::Bind(&GDataFileSystem::GetEntryInfoByPathAsyncOnUIThread,
                  ui_weak_ptr_,
                  file_path,
                  CreateRelayCallback(callback)));
 }
 
 void GDataFileSystem::GetEntryInfoByPathAsyncOnUIThread(
     const FilePath& file_path,
     const GetEntryInfoCallback& callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(!callback.is_null());
 
   FindEntryByPathAsyncOnUIThread(
       file_path,
       base::Bind(&GDataFileSystem::OnGetEntryInfo,
                  ui_weak_ptr_,
                  callback));
 }
 
 void GDataFileSystem::OnGetEntryInfo(const GetEntryInfoCallback& callback,
                                     GDataFileError error,
                                     GDataEntry* entry) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(!callback.is_null());
 
   if (error != GDATA_FILE_OK) {
-    if (!callback.is_null())
-      callback.Run(error, scoped_ptr<GDataEntryProto>());
+    callback.Run(error, scoped_ptr<GDataEntryProto>());
     return;
   }
   DCHECK(entry);
 
   scoped_ptr<GDataEntryProto> entry_proto(new GDataEntryProto);
   entry->ToProtoFull(entry_proto.get());
 
   CheckLocalModificationAndRun(entry_proto.Pass(), callback);
 }
 
@@ skipping 1493 matching lines @@
     return;
   }
 
   PlatformFileInfoProto entry_file_info;
   GDataEntry::ConvertPlatformFileInfoToProto(*file_info, &entry_file_info);
   *entry_proto->mutable_file_info() = entry_file_info;
   callback.Run(GDATA_FILE_OK, entry_proto.Pass());
 }
 
 }  // namespace gdata