Making GenericScopedHandle capable of handling handle types other than HANDLE.

chrome/service/cloud_print/print_system_win.cc

 // 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 "chrome/service/cloud_print/print_system.h"
 
 #include <objidl.h>
 #include <winspool.h>
 #include <xpsprint.h>
 
@@ skipping 15 matching lines @@
 #include "printing/emf_win.h"
 #include "printing/page_range.h"
 #include "printing/pdf_render_settings.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/rect.h"
 
 #pragma comment(lib, "rpcrt4.lib")  // for UuidToString & Co.
 
 namespace {
 
 class PrinterChangeHandleTraits {

[Vitaly Buka (NO REVIEWS), 2012/03/05 18:52:14]

: pubic HandleTraits

[alexeypa (please no reviews), 2012/03/05 18:56:58]

No, why? HandleTraits and PrinterChangeHandleTraits are unrelated. They both
happen to use HANDLE as the raw handle type but it does not make them related.

[brettw, 2012/03/05 18:58:44]

I would not necessarily expect that the traits classes derive from each other in
this type of situation, so I think the existing code is fine.

  public:
+  typedef HANDLE Handle;
+
   static bool CloseHandle(HANDLE handle) {
     return ::FindClosePrinterChangeNotification(handle) != FALSE;
   }
+
+  static bool IsHandleValid(HANDLE handle) {
+    return handle != NULL;
+  }
+
+  static HANDLE NullHandle() {
+    return NULL;
+  }
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(PrinterChangeHandleTraits);
 };
 
 typedef base::win::GenericScopedHandle<PrinterChangeHandleTraits>
     ScopedPrinterChangeHandle;
 
 class DevMode {
  public:
   DevMode() : dm_(NULL) {}
   ~DevMode() { Free(); }
 
@@ skipping 831 matching lines @@
   RpcStringFree(reinterpret_cast<RPC_WSTR *>(&proxy_id_as_string));
   return ret;
 }
 
 scoped_refptr<PrintSystem> PrintSystem::CreateInstance(
     const base::DictionaryValue* print_system_settings) {
   return new PrintSystemWin;
 }
 
 }  // namespace cloud_print