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

net/disk_cache/file_posix.cc

Index: net/disk_cache/file_posix.cc
===================================================================
--- net/disk_cache/file_posix.cc	(revision 126788)
+++ net/disk_cache/file_posix.cc	(working copy)
@@ -1,4 +1,4 @@
-// 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.
 
@@ -97,7 +97,7 @@
   } else {
     result_ = net::ERR_CACHE_READ_FAILURE;
   }
-  controller_->OnIOComplete(this);
+  NotifyController();
 }
 
 // Runs on a worker thread.
@@ -105,7 +105,7 @@
   bool rv = file_->Write(buf_, buf_len_, offset_);
 
   result_ = rv ? static_cast<int>(buf_len_) : net::ERR_CACHE_WRITE_FAILURE;
-  controller_->OnIOComplete(this);
+  NotifyController();
 }
 
 // ---------------------------------------------------------------------------
@@ -282,6 +282,12 @@
   DeleteFileInFlightIO();
 }
 
+// Static.
+void File::DropPendingIO() {
+  GetFileInFlightIO()->DropPendingIO();
+  DeleteFileInFlightIO();
+}
+
 File::~File() {
   if (IsValid())
     base::ClosePlatformFile(platform_file_);