Make DownloadItem derive SupportsUserData instead of re-implementing it.

content/browser/download/download_item_impl.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 "content/browser/download/download_item_impl.h"
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
@@ skipping 283 matching lines @@
       ALLOW_THIS_IN_INITIALIZER_LIST(weak_ptr_factory_(this)) {
   delegate_->Attach();
   Init(true /* actively downloading */,
        download_net_logs::SRC_SAVE_PAGE_AS);
 }
 
 DownloadItemImpl::~DownloadItemImpl() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   TransitionTo(REMOVING);
-  STLDeleteContainerPairSecondPointers(
-      external_data_map_.begin(), external_data_map_.end());
   delegate_->AssertStateConsistent(this);
   delegate_->Detach();
 }
 
 void DownloadItemImpl::AddObserver(Observer* observer) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   observers_.AddObserver(observer);
 }
 
@@ skipping 847 matching lines @@
 void DownloadItemImpl::SetOpened(bool opened) { opened_ = opened; }
 bool DownloadItemImpl::GetOpened() const { return opened_; }
 const std::string& DownloadItemImpl::GetLastModifiedTime() const {
   return last_modified_time_;
 }
 const std::string& DownloadItemImpl::GetETag() const { return etag_; }
 content::DownloadInterruptReason DownloadItemImpl::GetLastReason() const {
   return last_reason_;
 }
 void DownloadItemImpl::MockDownloadOpenForTesting() { open_enabled_ = false; }
-
-DownloadItem::ExternalData*
-DownloadItemImpl::GetExternalData(const void* key) {
-  // The behavior of the const overload is identical with the exception of the
-  // constness of |this| and the return value.
-  return const_cast<DownloadItem::ExternalData*>(
-      static_cast<const DownloadItemImpl&>(*this).GetExternalData(key));
-}
-
-const DownloadItem::ExternalData*
-DownloadItemImpl::GetExternalData(const void* key) const {
-  std::map<const void*, ExternalData*>::const_iterator it =
-      external_data_map_.find(key);
-  return (it == external_data_map_.end()) ? NULL : it->second;
-}
-
-void DownloadItemImpl::SetExternalData(
-    const void* key, DownloadItem::ExternalData* data) {
-  std::map<const void*, ExternalData*>::iterator it =
-      external_data_map_.find(key);
-
-  if (it == external_data_map_.end()) {
-    external_data_map_[key] = data;
-  } else if (it->second != data) {
-    delete it->second;
-    it->second = data;
-  }
-}