Implemented ExternalData interface on DownloadItem and used it for SafeBrowsing.

content/browser/download/download_item_impl.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 "content/browser/download/download_item_impl.h"
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/format_macros.h"
 #include "base/i18n/case_conversion.h"
 #include "base/i18n/string_search.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
+#include "base/stl_util.h"
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
 #include "content/browser/download/download_create_info.h"
 #include "content/browser/download/download_file.h"
 #include "content/browser/download/download_file_manager.h"
 #include "content/browser/download/download_id.h"
 #include "content/browser/download/download_persistent_store_info.h"
 #include "content/browser/download/download_request_handle.h"
 #include "content/browser/download/download_stats.h"
 #include "content/browser/download/interrupt_reasons.h"
@@ skipping 226 matching lines @@
       delegate_delayed_complete_(false) {
   delegate_->Attach();
   Init(true /* actively downloading */);
 }
 
 DownloadItemImpl::~DownloadItemImpl() {
   // TODO(rdsmith): Change to DCHECK after http://crbug.com/85408 resolved.
   CHECK(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) {
   // TODO(rdsmith): Change to DCHECK after http://crbug.com/85408 resolved.
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   observers_.AddObserver(observer);
 }
@@ skipping 648 matching lines @@
 void DownloadItemImpl::SetOpened(bool opened) { opened_ = opened; }
 bool DownloadItemImpl::GetOpened() const { return opened_; }
 InterruptReason DownloadItemImpl::GetLastReason() const {
   return last_reason_;
 }
 DownloadStateInfo DownloadItemImpl::GetStateInfo() const { return state_info_; }
 bool DownloadItemImpl::NeedsRename() const {
   return state_info_.target_name != full_path_.BaseName();
 }
 void DownloadItemImpl::MockDownloadOpenForTesting() { open_enabled_ = false; }
+
+DownloadItem::ExternalData*
+DownloadItemImpl::GetExternalData(const void* key) {
+  if (!ContainsKey(external_data_map_, key))
+    return NULL;
+  return external_data_map_[key];
+}
+
+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;
+  }
+}