Fix race condition for non-open/create operations happening after a doom.

net/disk_cache/simple/simple_entry_impl.h

Index: net/disk_cache/simple/simple_entry_impl.h
diff --git a/net/disk_cache/simple/simple_entry_impl.h b/net/disk_cache/simple/simple_entry_impl.h
index 7eb8914e8731ab73d1dca0ef0b394b678123db87..e3a948723024beb07b0d7e1b121db530623e833c 100644
--- a/net/disk_cache/simple/simple_entry_impl.h
+++ b/net/disk_cache/simple/simple_entry_impl.h
@@ -177,6 +177,8 @@ class SimpleEntryImpl : public Entry, public base::RefCounted<SimpleEntryImpl>,
                          const CompletionCallback& callback,
                          bool truncate);
 
+  void DoomEntryInternal(const CompletionCallback& callback);
+
   // Called after a SimpleSynchronousEntry has completed CreateEntry() or
   // OpenEntry(). If |in_sync_entry| is non-NULL, creation is successful and we
   // can return |this| SimpleEntryImpl to |*out_entry|. Runs
@@ -214,6 +216,12 @@ class SimpleEntryImpl : public Entry, public base::RefCounted<SimpleEntryImpl>,
                               scoped_ptr<SimpleEntryStat> entry_stat,
                               scoped_ptr<int> result);
 
+  // Called after an asynchronous doom completes. |state_to_restore| was the
+  // state of the entry instance before it transitioned to IO_PENDING.
+  void DoomOperationComplete(State state_to_restore,
+                             const CompletionCallback& callback,
+                             int result);
+
   // Called after validating the checksums on an entry. Passes through the
   // original result if successful, propogates the error if the checksum does
   // not validate.
@@ -274,8 +282,7 @@ class SimpleEntryImpl : public Entry, public base::RefCounted<SimpleEntryImpl>,
   CheckCrcResult crc_check_state_[kSimpleEntryFileCount];
 
   // The |synchronous_entry_| is the worker thread object that performs IO on
-  // entries. It's owned by this SimpleEntryImpl whenever |operation_running_|
-  // is false (i.e. when an operation is not pending on the worker pool).

[Randy Smith (Not in Mondays), 2013/08/27 19:16:39]

I'd really like to keep a comment here describing the ownership of the
SimpleSynchronousEntry.   The ownership model isn't simple; SEI owns it, but
commits to not deleting it, and the only way it will be deleted is by post to
SSE::Close.  I'd like to have that sketched out here.  (I'd even more like to
have it self-documented by passing scoped_ptrs around, but that might require
some more complex re-working of the code.)

+  // entries.
   SimpleSynchronousEntry* synchronous_entry_;
 
   std::queue<SimpleEntryOperation> pending_operations_;