Add interface to CancelableRequest that allows use of base::Callback<>.

chrome/browser/icon_manager.cc

 // Copyright (c) 2011 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/browser/icon_manager.h"
 
 #include "base/file_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/stl_util.h"
 #include "third_party/skia/include/core/SkBitmap.h"
@@ skipping 19 matching lines @@
   if (it != icon_cache_.end())
     return it->second;
 
   return NULL;
 }
 
 IconManager::Handle IconManager::LoadIcon(
     const FilePath& file_name,
     IconLoader::IconSize size,
     CancelableRequestConsumerBase* consumer,
-    IconRequestCallback* callback) {
+    const IconRequestCallback& callback) {
   IconGroupID group = GetGroupIDFromFilepath(file_name);
   IconRequest* request = new IconRequest(callback);
   AddRequest(request, consumer);
 
   IconLoader* loader = new IconLoader(group, size, this);
   loader->AddRef();
   loader->Start();
   ClientRequest client_request = { request, group, size };
   requests_[loader] = client_request;
   return request->handle();
@@ skipping 25 matching lines @@
   if (it != icon_cache_.end() && result && it->second) {
     it->second->SwapRepresentations(result);
     delete result;
     result = it->second;
   } else {
     icon_cache_[key] = result;
   }
 
   // Inform our client that the request has completed.
   IconRequest* icon_request = client_request.request;
-  icon_request->ForwardResult(IconRequest::TupleType(icon_request->handle(),
-                                                     result));
+  icon_request->ForwardResult(icon_request->handle(), result);
   requests_.erase(rit);
 
   return true;  // Indicates we took ownership of result.
 }
 
 IconManager::CacheKey::CacheKey(const IconGroupID& group,
                                 IconLoader::IconSize size)
     : group(group),
       size(size) {
 }
 
 bool IconManager::CacheKey::operator<(const CacheKey &other) const {
   if (group != other.group)
     return group < other.group;
   return size < other.size;
 }