Disk cache: Remove all non essential synchronization from the cache destructor.

net/disk_cache/file_posix.cc

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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 "net/disk_cache/file.h"
 
 #include <fcntl.h>
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
@@ skipping 78 matching lines @@
 
 // ---------------------------------------------------------------------------
 
 // Runs on a worker thread.
 void FileBackgroundIO::Read() {
   if (file_->Read(const_cast<void*>(buf_), buf_len_, offset_)) {
     result_ = static_cast<int>(buf_len_);
   } else {
     result_ = net::ERR_CACHE_READ_FAILURE;
   }
-  controller_->OnIOComplete(this);
+  NotifyController();
 }
 
 // Runs on a worker thread.
 void FileBackgroundIO::Write() {
   bool rv = file_->Write(buf_, buf_len_, offset_);
 
   result_ = rv ? static_cast<int>(buf_len_) : net::ERR_CACHE_WRITE_FAILURE;
-  controller_->OnIOComplete(this);
+  NotifyController();
 }
 
 // ---------------------------------------------------------------------------
 
 void FileInFlightIO::PostRead(disk_cache::File *file, void* buf, size_t buf_len,
                           size_t offset, disk_cache::FileIOCallback *callback) {
   scoped_refptr<FileBackgroundIO> operation(
       new FileBackgroundIO(file, buf, buf_len, offset, callback, this));
   file->AddRef();  // Balanced on OnOperationComplete()
 
@@ skipping 156 matching lines @@
 }
 
 // Static.
 void File::WaitForPendingIO(int* num_pending_io) {
   // We may be running unit tests so we should allow be able to reset the
   // message loop.
   GetFileInFlightIO()->WaitForPendingIO();
   DeleteFileInFlightIO();
 }
 
+// Static.
+void File::DropPendingIO() {
+  GetFileInFlightIO()->DropPendingIO();
+  DeleteFileInFlightIO();
+}
+
 File::~File() {
   if (IsValid())
     base::ClosePlatformFile(platform_file_);
 }
 
 bool File::AsyncWrite(const void* buffer, size_t buffer_len, size_t offset,
                       FileIOCallback* callback, bool* completed) {
   DCHECK(init_);
   if (buffer_len > ULONG_MAX || offset > ULONG_MAX)
     return false;
 
   GetFileInFlightIO()->PostWrite(this, buffer, buffer_len, offset, callback);
 
   if (completed)
     *completed = false;
   return true;
 }
 
 }  // namespace disk_cache