Disk Cache: Replace the backend pointer of the ChildrenDeleter...

net/disk_cache/sparse_control.cc

Index: net/disk_cache/sparse_control.cc
===================================================================
--- net/disk_cache/sparse_control.cc	(revision 53428)
+++ net/disk_cache/sparse_control.cc	(working copy)
@@ -51,7 +51,7 @@
       public disk_cache::FileIOCallback {
  public:
   ChildrenDeleter(disk_cache::BackendImpl* backend, const std::string& name)
-      : backend_(backend), name_(name) {}
+      : backend_(backend->GetWeakPtr()), name_(name) {}
 
   virtual void OnFileIOComplete(int bytes_copied);
 
@@ -66,7 +66,7 @@
 
   void DeleteChildren();
 
-  disk_cache::BackendImpl* backend_;
+  base::WeakPtr<disk_cache::BackendImpl> backend_;
   std::string name_;
   disk_cache::Bitmap children_map_;
   int64 signature_;
@@ -101,6 +101,9 @@
 
 void ChildrenDeleter::ReadData(disk_cache::Addr address, int len) {
   DCHECK(address.is_block_file());
+  if (!backend_)
+    return Release();
+
   disk_cache::File* file(backend_->File(address));
   if (!file)
     return Release();
@@ -121,7 +124,7 @@
 
 void ChildrenDeleter::DeleteChildren() {
   int child_id = 0;
-  if (!children_map_.FindNextSetBit(&child_id)) {
+  if (!children_map_.FindNextSetBit(&child_id) || !backend_) {
     // We are done. Just delete this object.
     return Release();
   }