Removed unnecessary DCHECK on entry

Addresses discussion in code review iossue 10828025.


BUG=
TEST=


Review URL: https://chromiumcodereview.appspot.com/10821039

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@148598 0039d316-1c4b-4281-b951-d872f2087c98

net/disk_cache/sparse_control.cc

@@ -332,7 +332,6 @@ int SparseControl::ReadyToUse(const CompletionCallback& callback) {
 
 // Static
 void SparseControl::DeleteChildren(EntryImpl* entry) {
-  DCHECK(entry);
   DCHECK(entry->GetEntryFlags() & PARENT_ENTRY);
   int data_len = entry->GetDataSize(kSparseIndex);
   if (data_len < static_cast<int>(sizeof(SparseData)) ||