Get rid of DownloadIdFactory and instead get the next id from DownloadManagerDelegate. I've also moved DownloadId to the public directory and into the content namespace.

BUG=98716
Review URL: https://chromiumcodereview.appspot.com/9169036

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@119310 0039d316-1c4b-4281-b951-d872f2087c98

52 files changed, 214 insertions, 303 deletions

diff --git a/chrome/browser/DEPS b/chrome/browser/DEPS
index 24c0c38..782262b 100644
--- a/chrome/browser/DEPS
+++ b/chrome/browser/DEPS
@@ -44,8 +44,6 @@ include_rules = [
   "+content/browser/download/download_create_info.h",
   "+content/browser/download/download_file_impl.h",
   "+content/browser/download/download_file_manager.h",
-  "+content/browser/download/download_id.h",
-  "+content/browser/download/download_id_factory.h",
   "+content/browser/download/download_item_impl.h",
   "+content/browser/download/download_persistent_store_info.h",
   "+content/browser/download/download_request_handle.h",
diff --git a/chrome/browser/download/chrome_download_manager_delegate.cc b/chrome/browser/download/chrome_download_manager_delegate.cc
index 4c3cd71..73856ba 100644
--- a/chrome/browser/download/chrome_download_manager_delegate.cc
+++ b/chrome/browser/download/chrome_download_manager_delegate.cc
@@ -43,6 +43,7 @@
 
 using content::BrowserThread;
 using content::DownloadFile;
+using content::DownloadId;
 using content::DownloadItem;
 using content::DownloadManager;
 using content::WebContents;
@@ -66,6 +67,7 @@ struct SafeBrowsingState : public DownloadItem::ExternalData {
 
 ChromeDownloadManagerDelegate::ChromeDownloadManagerDelegate(Profile* profile)
     : profile_(profile),
+      next_download_id_(0),
       download_prefs_(new DownloadPrefs(profile->GetPrefs())) {
 }
 
@@ -94,6 +96,14 @@ void ChromeDownloadManagerDelegate::Shutdown() {
   download_prefs_.reset();
 }
 
+DownloadId ChromeDownloadManagerDelegate::GetNextId() {
+  if (!profile_->IsOffTheRecord())
+    return DownloadId(this, next_download_id_++);
+
+  return profile_->GetOriginalProfile()->GetDownloadManager()->delegate()->
+      GetNextId();
+}
+
 bool ChromeDownloadManagerDelegate::ShouldStartDownload(int32 download_id) {
   // We create a download item and store it in our download map, and inform the
   // history system of a new download. Since this method can be called while the
diff --git a/chrome/browser/download/chrome_download_manager_delegate.h b/chrome/browser/download/chrome_download_manager_delegate.h
index b04282e..d0464763 100644
--- a/chrome/browser/download/chrome_download_manager_delegate.h
+++ b/chrome/browser/download/chrome_download_manager_delegate.h
@@ -54,6 +54,7 @@ class ChromeDownloadManagerDelegate
   static bool IsExtensionDownload(const content::DownloadItem* item);
 
   virtual void Shutdown() OVERRIDE;
+  virtual content::DownloadId GetNextId() OVERRIDE;
   virtual bool ShouldStartDownload(int32 download_id) OVERRIDE;
   virtual void ChooseDownloadPath(content::WebContents* web_contents,
                                   const FilePath& suggested_path,
@@ -151,6 +152,7 @@ class ChromeDownloadManagerDelegate
   void OnItemAddedToPersistentStore(int32 download_id, int64 db_handle);
 
   Profile* profile_;
+  int next_download_id_;
   scoped_ptr<DownloadPrefs> download_prefs_;
   scoped_ptr<DownloadHistory> download_history_;
 
diff --git a/chrome/browser/download/download_extension_api.cc b/chrome/browser/download/download_extension_api.cc
index ea638ae..eef4509 100644
--- a/chrome/browser/download/download_extension_api.cc
+++ b/chrome/browser/download/download_extension_api.cc
@@ -36,7 +36,6 @@
 #include "chrome/browser/renderer_host/chrome_render_message_filter.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/webui/web_ui_util.h"
-#include "content/browser/download/download_id.h"
 #include "content/browser/download/download_state_info.h"
 #include "content/browser/download/download_types.h"
 #include "content/browser/download/interrupt_reasons.h"
@@ -49,6 +48,7 @@
 #include "net/url_request/url_request.h"
 
 using content::BrowserThread;
+using content::DownloadId;
 using content::DownloadItem;
 using content::DownloadManager;
 using content::DownloadQuery;
@@ -459,7 +459,7 @@ void DownloadsDownloadFunction::BeginDownloadOnIOThread() {
     request->AppendBytesToUpload(iodata_->post_body.data(),
                                  iodata_->post_body.size());
   }
-  iodata_->rdh->BeginDownload(
+  net::Error error = iodata_->rdh->BeginDownload(
       request.Pass(),
       save_info,
       iodata_->save_as,
@@ -468,21 +468,20 @@ void DownloadsDownloadFunction::BeginDownloadOnIOThread() {
       iodata_->render_view_host_routing_id,
       *(iodata_->resource_context));
   iodata_.reset();
-}
 
-void DownloadsDownloadFunction::OnStarted(DownloadId dl_id, net::Error error) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  VLOG(1) << __FUNCTION__ << " " << dl_id << " " << error;
-  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, base::Bind(
-      &DownloadsDownloadFunction::RespondOnUIThread, this,
-      dl_id.local(), error));
+  if (error != net::OK) {
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(&DownloadsDownloadFunction::OnStarted, this,
+                   DownloadId::Invalid(), error));
+  }
 }
 
-void DownloadsDownloadFunction::RespondOnUIThread(int dl_id, net::Error error) {
+void DownloadsDownloadFunction::OnStarted(DownloadId dl_id, net::Error error) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  VLOG(1) << __FUNCTION__;
-  if (dl_id >= 0) {
-    result_.reset(base::Value::CreateIntegerValue(dl_id));
+  VLOG(1) << __FUNCTION__ << " " << dl_id << " " << error;
+  if (dl_id.local() >= 0) {
+    result_.reset(base::Value::CreateIntegerValue(dl_id.local()));
   } else {
     error_ = net::ErrorToString(error);
   }
diff --git a/chrome/browser/download/download_extension_api.h b/chrome/browser/download/download_extension_api.h
index 7e6b8c8..c629be2 100644
--- a/chrome/browser/download/download_extension_api.h
+++ b/chrome/browser/download/download_extension_api.h
@@ -15,6 +15,7 @@
 #include "base/string16.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/extension_function.h"
+#include "content/public/browser/download_id.h"
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/download_manager.h"
 
@@ -139,8 +140,7 @@ class DownloadsDownloadFunction : public AsyncDownloadsFunction {
     int render_view_host_routing_id;
   };
   void BeginDownloadOnIOThread();
-  void OnStarted(DownloadId dl_id, net::Error error);
-  void RespondOnUIThread(int dl_id, net::Error error);
+  void OnStarted(content::DownloadId dl_id, net::Error error);
 
   scoped_ptr<IOData> iodata_;
 
diff --git a/chrome/browser/download/download_item_unittest.cc b/chrome/browser/download/download_item_unittest.cc
index 41c6cf6..dcafc04 100644
--- a/chrome/browser/download/download_item_unittest.cc
+++ b/chrome/browser/download/download_item_unittest.cc
@@ -7,18 +7,18 @@
 #include "base/threading/thread.h"
 #include "chrome/test/base/testing_profile.h"
 #include "content/browser/download/download_create_info.h"
-#include "content/browser/download/download_id.h"
-#include "content/browser/download/download_id_factory.h"
 #include "content/browser/download/download_item_impl.h"
 #include "content/browser/download/download_request_handle.h"
 #include "content/browser/download/download_status_updater.h"
 #include "content/browser/download/interrupt_reasons.h"
 #include "content/browser/download/mock_download_item.h"
+#include "content/public/browser/download_id.h"
 #include "content/test/test_browser_thread.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using content::BrowserThread;
+using content::DownloadId;
 using content::DownloadItem;
 using content::DownloadManager;
 
@@ -78,8 +78,7 @@ class DownloadItemTest : public testing::Test {
   };
 
   DownloadItemTest()
-      : id_factory_(new DownloadIdFactory(kValidDownloadItemIdDomain)),
-        ui_thread_(BrowserThread::UI, &loop_) {
+      : ui_thread_(BrowserThread::UI, &loop_) {
   }
 
   ~DownloadItemTest() {
@@ -104,7 +103,9 @@ class DownloadItemTest : public testing::Test {
     scoped_ptr<DownloadCreateInfo> info_;
 
     info_.reset(new DownloadCreateInfo());
-    info_->download_id = id_factory_->GetNextId();
+    static int next_id;
+    info_->download_id =
+        content::DownloadId(kValidDownloadItemIdDomain, ++next_id);
     info_->prompt_user_for_save_location = false;
     info_->url_chain.push_back(GURL());
     info_->state = state;
@@ -128,7 +129,6 @@ class DownloadItemTest : public testing::Test {
   DownloadStatusUpdater download_status_updater_;
 
  private:
-  scoped_refptr<DownloadIdFactory> id_factory_;
   MessageLoopForUI loop_;
   // UI thread.
   content::TestBrowserThread ui_thread_;
diff --git a/chrome/browser/download/download_manager_unittest.cc b/chrome/browser/download/download_manager_unittest.cc
index 2b303e8..59723fe 100644
--- a/chrome/browser/download/download_manager_unittest.cc
+++ b/chrome/browser/download/download_manager_unittest.cc
@@ -28,7 +28,6 @@
 #include "content/browser/download/download_create_info.h"
 #include "content/browser/download/download_file_impl.h"
 #include "content/browser/download/download_file_manager.h"
-#include "content/browser/download/download_id_factory.h"
 #include "content/browser/download/download_request_handle.h"
 #include "content/browser/download/download_status_updater.h"
 #include "content/browser/download/interrupt_reasons.h"
@@ -66,6 +65,7 @@
 
 using content::BrowserThread;
 using content::DownloadFile;
+using content::DownloadId;
 using content::DownloadItem;
 using content::DownloadManager;
 using ::testing::ReturnRef;
@@ -176,11 +176,8 @@ class DownloadManagerTest : public testing::Test {
       : profile_(new TestingProfile()),
         download_manager_delegate_(new TestDownloadManagerDelegate(
             profile_.get())),
-        id_factory_(new DownloadIdFactory(kValidIdDomain)),
         download_manager_(DownloadManager::Create(
-            download_manager_delegate_,
-            id_factory_,
-            &download_status_updater_)),
+            download_manager_delegate_, &download_status_updater_)),
         ui_thread_(BrowserThread::UI, &message_loop_),
         file_thread_(BrowserThread::FILE, &message_loop_),
         download_buffer_(new content::DownloadBuffer) {
@@ -255,7 +252,6 @@ class DownloadManagerTest : public testing::Test {
   DownloadStatusUpdater download_status_updater_;
   scoped_ptr<TestingProfile> profile_;
   scoped_refptr<TestDownloadManagerDelegate> download_manager_delegate_;
-  scoped_refptr<DownloadIdFactory> id_factory_;
   scoped_refptr<DownloadManager> download_manager_;
   scoped_refptr<DownloadFileManager> file_manager_;
   MessageLoopForUI message_loop_;
diff --git a/chrome/browser/download/download_service.cc b/chrome/browser/download/download_service.cc
index 98031ec..65e1124 100644
--- a/chrome/browser/download/download_service.cc
+++ b/chrome/browser/download/download_service.cc
@@ -10,7 +10,6 @@
 #include "chrome/browser/download/download_service_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
-#include "content/browser/download/download_id_factory.h"
 #include "content/public/browser/download_manager.h"
 
 using content::DownloadManager;
@@ -18,20 +17,10 @@ using content::DownloadManager;
 DownloadService::DownloadService(Profile* profile)
     : download_manager_created_(false),
       profile_(profile) {
-  if (profile_->IsOffTheRecord()) {
-    id_factory_ = DownloadServiceFactory::GetForProfile(
-        profile_->GetOriginalProfile())->GetDownloadIdFactory();
-  } else {
-    id_factory_ = new DownloadIdFactory(this);
-  }
 }
 
 DownloadService::~DownloadService() {}
 
-DownloadIdFactory* DownloadService::GetDownloadIdFactory() const {
-  return id_factory_.get();
-}
-
 void DownloadService::OnManagerCreated(
     const DownloadService::OnManagerCreatedCallback& cb) {
   if (download_manager_created_) {
@@ -48,9 +37,7 @@ DownloadManager* DownloadService::GetDownloadManager() {
     if (!manager_delegate_.get())
       manager_delegate_ = new ChromeDownloadManagerDelegate(profile_);
     manager_ = DownloadManager::Create(
-        manager_delegate_.get(),
-        id_factory_.get(),
-        g_browser_process->download_status_updater());
+        manager_delegate_.get(), g_browser_process->download_status_updater());
     manager_->Init(profile_);
     manager_delegate_->SetDownloadManager(manager_);
     download_manager_created_ = true;
diff --git a/chrome/browser/download/download_service.h b/chrome/browser/download/download_service.h
index fb9f24a7..b513199 100644
--- a/chrome/browser/download/download_service.h
+++ b/chrome/browser/download/download_service.h
@@ -16,7 +16,6 @@
 
 class ChromeDownloadManagerDelegate;
 class Profile;
-class DownloadIdFactory;
 
 namespace content {
 class DownloadManager;
@@ -29,8 +28,6 @@ class DownloadService : public ProfileKeyedService {
   explicit DownloadService(Profile* profile);
   virtual ~DownloadService();
 
-  DownloadIdFactory* GetDownloadIdFactory() const;
-
   // Register a callback to be called whenever the DownloadManager is created.
   typedef base::Callback<void(content::DownloadManager*)>
       OnManagerCreatedCallback;
@@ -60,8 +57,6 @@ class DownloadService : public ProfileKeyedService {
   virtual void Shutdown() OVERRIDE;
 
  private:
-  scoped_refptr<DownloadIdFactory> id_factory_;
-
   bool download_manager_created_;
   Profile* profile_;
 
diff --git a/chrome/browser/download/download_throttling_resource_handler.cc b/chrome/browser/download/download_throttling_resource_handler.cc
index 3d98eee..85bc6e1 100644
--- a/chrome/browser/download/download_throttling_resource_handler.cc
+++ b/chrome/browser/download/download_throttling_resource_handler.cc
@@ -7,7 +7,6 @@
 #include "base/logging.h"
 #include "chrome/browser/download/download_request_limiter.h"
 #include "chrome/browser/download/download_util.h"
-#include "content/browser/download/download_id.h"
 #include "content/browser/renderer_host/resource_dispatcher_host.h"
 #include "content/public/common/resource_response.h"
 #include "net/base/io_buffer.h"
diff --git a/chrome/browser/profiles/profile_io_data.cc b/chrome/browser/profiles/profile_io_data.cc
index 514f42d..f58e43a 100644
--- a/chrome/browser/profiles/profile_io_data.cc
+++ b/chrome/browser/profiles/profile_io_data.cc
@@ -41,7 +41,6 @@
 #include "chrome/common/url_constants.h"
 #include "content/browser/appcache/chrome_appcache_service.h"
 #include "content/browser/chrome_blob_storage_context.h"
-#include "content/browser/download/download_id_factory.h"
 #include "content/browser/host_zoom_map.h"
 #include "content/browser/renderer_host/media/media_stream_manager.h"
 #include "content/browser/renderer_host/resource_dispatcher_host.h"
@@ -188,9 +187,6 @@ void ProfileIOData::InitializeOnUIThread(Profile* profile) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   PrefService* pref_service = profile->GetPrefs();
 
-  download_id_factory_ = DownloadServiceFactory::GetForProfile(profile)->
-    GetDownloadIdFactory();
-
   scoped_ptr<ProfileParams> params(new ProfileParams);
   params->path = profile->GetPath();
   params->is_incognito = profile->IsOffTheRecord();
@@ -515,7 +511,6 @@ void ProfileIOData::LazyInitialize() const {
   resource_context_.SetUserData(NULL, const_cast<ProfileIOData*>(this));
   resource_context_.set_media_observer(
       io_thread_globals->media.media_internals.get());
-  resource_context_.set_download_id_factory(download_id_factory_);
   resource_context_.set_media_stream_manager(media_stream_manager_.get());
   resource_context_.set_audio_manager(profile_params_->audio_manager);
 
diff --git a/chrome/browser/profiles/profile_io_data.h b/chrome/browser/profiles/profile_io_data.h
index 1eac7a7..349d747 100644
--- a/chrome/browser/profiles/profile_io_data.h
+++ b/chrome/browser/profiles/profile_io_data.h
@@ -25,7 +25,6 @@ class ChromeAppCacheService;
 class ChromeBlobStorageContext;
 class CookieSettings;
 class DesktopNotificationService;
-class DownloadIdFactory;
 class ExtensionInfoMap;
 class HostContentSettingsMap;
 class HostZoomMap;
@@ -290,7 +289,6 @@ class ProfileIOData {
   mutable scoped_refptr<fileapi::FileSystemContext> file_system_context_;
   mutable scoped_refptr<quota::QuotaManager> quota_manager_;
   mutable scoped_refptr<HostZoomMap> host_zoom_map_;
-  mutable scoped_refptr<DownloadIdFactory> download_id_factory_;
   mutable scoped_ptr<media_stream::MediaStreamManager> media_stream_manager_;
 
   // TODO(willchan): Remove from ResourceContext.
diff --git a/content/browser/download/download_create_info.cc b/content/browser/download/download_create_info.cc
index fbcd175..08999f7 100644
--- a/content/browser/download/download_create_info.cc
+++ b/content/browser/download/download_create_info.cc
@@ -9,22 +9,24 @@
 #include "base/format_macros.h"
 #include "base/stringprintf.h"
 
-DownloadCreateInfo::DownloadCreateInfo(const FilePath& path,
-                                       const GURL& url,
-                                       const base::Time& start_time,
-                                       int64 received_bytes,
-                                       int64 total_bytes,
-                                       int32 state,
-                                       const DownloadId& download_id,
-                                       bool has_user_gesture,
-                                       content::PageTransition transition_type)
+using content::DownloadId;
+
+DownloadCreateInfo::DownloadCreateInfo(
+    const FilePath& path,
+    const GURL& url,
+    const base::Time& start_time,
+    int64 received_bytes,
+    int64 total_bytes,
+    int32 state,
+    bool has_user_gesture,
+    content::PageTransition transition_type)
     : path(path),
       url_chain(1, url),
       start_time(start_time),
       received_bytes(received_bytes),
       total_bytes(total_bytes),
       state(state),
-      download_id(download_id),
+      download_id(DownloadId::Invalid()),
       has_user_gesture(has_user_gesture),
       transition_type(transition_type),
       db_handle(0),
diff --git a/content/browser/download/download_create_info.h b/content/browser/download/download_create_info.h
index 9be00c1..dbfee7f 100644
--- a/content/browser/download/download_create_info.h
+++ b/content/browser/download/download_create_info.h
@@ -12,10 +12,10 @@
 #include "base/basictypes.h"
 #include "base/file_path.h"
 #include "base/time.h"
-#include "content/browser/download/download_id.h"
 #include "content/browser/download/download_types.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/download_file.h"
+#include "content/public/browser/download_id.h"
 #include "content/public/common/page_transition_types.h"
 #include "googleurl/src/gurl.h"
 
@@ -28,7 +28,6 @@ struct CONTENT_EXPORT DownloadCreateInfo {
                      int64 received_bytes,
                      int64 total_bytes,
                      int32 state,
-                     const DownloadId& download_id,
                      bool has_user_gesture,
                      content::PageTransition transition_type);
   DownloadCreateInfo();
@@ -63,7 +62,7 @@ struct CONTENT_EXPORT DownloadCreateInfo {
   int32 state;
 
   // The (per-session) ID of the download.
-  DownloadId download_id;
+  content::DownloadId download_id;
 
   // True if the download was initiated by user action.
   bool has_user_gesture;
diff --git a/content/browser/download/download_file_impl.cc b/content/browser/download/download_file_impl.cc
index 4cff9e8..408081a 100644
--- a/content/browser/download/download_file_impl.cc
+++ b/content/browser/download/download_file_impl.cc
@@ -13,6 +13,7 @@
 #include "content/public/browser/download_manager.h"
 
 using content::BrowserThread;
+using content::DownloadId;
 
 namespace {
 
diff --git a/content/browser/download/download_file_impl.h b/content/browser/download/download_file_impl.h
index 69a7c5e..0521435 100644
--- a/content/browser/download/download_file_impl.h
+++ b/content/browser/download/download_file_impl.h
@@ -49,7 +49,7 @@ class CONTENT_EXPORT DownloadFileImpl : virtual public content::DownloadFile {
   virtual void CancelDownloadRequest() OVERRIDE;
   virtual int Id() const OVERRIDE;
   virtual content::DownloadManager* GetDownloadManager() OVERRIDE;
-  virtual const DownloadId& GlobalId() const OVERRIDE;
+  virtual const content::DownloadId& GlobalId() const OVERRIDE;
   virtual std::string DebugString() const OVERRIDE;
 
  private:
@@ -58,7 +58,7 @@ class CONTENT_EXPORT DownloadFileImpl : virtual public content::DownloadFile {
 
   // The unique identifier for this download, assigned at creation by
   // the DownloadFileManager for its internal record keeping.
-  DownloadId id_;
+  content::DownloadId id_;
 
   // The handle to the request information.  Used for operations outside the
   // download system, specifically canceling a download.
diff --git a/content/browser/download/download_file_manager.cc b/content/browser/download/download_file_manager.cc
index 4a1f771..a58cb78 100644
--- a/content/browser/download/download_file_manager.cc
+++ b/content/browser/download/download_file_manager.cc
@@ -29,6 +29,7 @@
 
 using content::BrowserThread;
 using content::DownloadFile;
+using content::DownloadId;
 
 namespace {
 
diff --git a/content/browser/download/download_file_manager.h b/content/browser/download/download_file_manager.h
index 4688835..1a3054ef 100644
--- a/content/browser/download/download_file_manager.h
+++ b/content/browser/download/download_file_manager.h
@@ -49,9 +49,9 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/timer.h"
-#include "content/browser/download/download_id.h"
 #include "content/browser/download/interrupt_reasons.h"
 #include "content/common/content_export.h"
+#include "content/public/browser/download_id.h"
 #include "net/base/net_errors.h"
 #include "ui/gfx/native_widget_types.h"
 
@@ -96,14 +96,15 @@ class CONTENT_EXPORT DownloadFileManager
 
   // Handlers for notifications sent from the IO thread and run on the
   // FILE thread.
-  void UpdateDownload(DownloadId global_id, content::DownloadBuffer* buffer);
+  void UpdateDownload(content::DownloadId global_id,
+                      content::DownloadBuffer* buffer);
 
   // |reason| is the reason for interruption, if one occurs.
   // |security_info| contains SSL information (cert_id, cert_status,
   // security_bits, ssl_connection_status), which can be used to
   // fine-tune the error message.  It is empty if the transaction
   // was not performed securely.
-  void OnResponseCompleted(DownloadId global_id,
+  void OnResponseCompleted(content::DownloadId global_id,
                            InterruptReason reason,
                            const std::string& security_info);
 
@@ -112,22 +113,23 @@ class CONTENT_EXPORT DownloadFileManager
   // download file, as far as the DownloadFileManager is concerned -- if
   // anything happens to the download file after they are called, it will
   // be ignored.
-  void CancelDownload(DownloadId id);
-  void CompleteDownload(DownloadId id);
+  void CancelDownload(content::DownloadId id);
+  void CompleteDownload(content::DownloadId id);
 
   // Called on FILE thread by DownloadManager at the beginning of its shutdown.
   void OnDownloadManagerShutdown(content::DownloadManager* manager);
 
   // The DownloadManager in the UI thread has provided an intermediate
   // .crdownload name for the download specified by |id|.
-  void RenameInProgressDownloadFile(DownloadId id, const FilePath& full_path);
+  void RenameInProgressDownloadFile(content::DownloadId id,
+                                    const FilePath& full_path);
 
   // The DownloadManager in the UI thread has provided a final name for the
   // download specified by |id|.
   // |overwrite_existing_file| prevents uniquification, and is used for SAFE
   // downloads, as the user may have decided to overwrite the file.
   // Sent from the UI thread and run on the FILE thread.
-  void RenameCompletingDownloadFile(DownloadId id,
+  void RenameCompletingDownloadFile(content::DownloadId id,
                                     const FilePath& full_path,
                                     bool overwrite_existing_file);
 
@@ -161,18 +163,20 @@ class CONTENT_EXPORT DownloadFileManager
                           bool hash_needed);
 
   // Called only on the download thread.
-  content::DownloadFile* GetDownloadFile(DownloadId global_id);
+  content::DownloadFile* GetDownloadFile(content::DownloadId global_id);
 
   // Called only from RenameInProgressDownloadFile and
   // RenameCompletingDownloadFile on the FILE thread.
   // |rename_error| indicates what error caused the cancel.
-  void CancelDownloadOnRename(DownloadId global_id, net::Error rename_error);
+  void CancelDownloadOnRename(content::DownloadId global_id,
+                              net::Error rename_error);
 
   // Erases the download file with the given the download |id| and removes
   // it from the maps.
-  void EraseDownload(DownloadId global_id);
+  void EraseDownload(content::DownloadId global_id);
 
-  typedef base::hash_map<DownloadId, content::DownloadFile*> DownloadFileMap;
+  typedef base::hash_map<content::DownloadId, content::DownloadFile*>
+      DownloadFileMap;
 
   // A map of all in progress downloads.  It owns the download files.
   DownloadFileMap downloads_;
diff --git a/content/browser/download/download_file_manager_unittest.cc b/content/browser/download/download_file_manager_unittest.cc
index ccbe34c..de710f2 100644
--- a/content/browser/download/download_file_manager_unittest.cc
+++ b/content/browser/download/download_file_manager_unittest.cc
@@ -11,13 +11,12 @@
 #include "content/browser/browser_thread_impl.h"
 #include "content/browser/download/download_buffer.h"
 #include "content/browser/download/download_create_info.h"
-#include "content/browser/download/download_id.h"
-#include "content/browser/download/download_id_factory.h"
 #include "content/browser/download/download_request_handle.h"
 #include "content/browser/download/download_status_updater.h"
 #include "content/browser/download/mock_download_file.h"
 #include "content/browser/download/mock_download_manager.h"
 #include "content/browser/download/mock_download_manager_delegate.h"
+#include "content/public/browser/download_id.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ -25,6 +24,7 @@
 
 using content::BrowserThread;
 using content::BrowserThreadImpl;
+using content::DownloadId;
 
 using ::testing::_;
 using ::testing::AtLeast;
@@ -34,8 +34,6 @@ using ::testing::StrEq;
 
 namespace {
 
-DownloadId::Domain kValidIdDomain = "valid DownloadId::Domain";
-
 class MockDownloadFileFactory :
     public DownloadFileManager::DownloadFileFactory {
 
@@ -114,7 +112,6 @@ class DownloadFileManagerTest : public testing::Test {
   // destructor being called and we get a leak.
   DownloadFileManagerTest()
     : download_buffer_(new content::DownloadBuffer()),
-      id_factory_(new DownloadIdFactory(kValidIdDomain)),
       ui_thread_(BrowserThread::UI, &loop_),
       file_thread_(BrowserThread::FILE, &loop_) {
   }
@@ -431,7 +428,6 @@ class DownloadFileManagerTest : public testing::Test {
 
  private:
   MessageLoop loop_;
-  scoped_refptr<DownloadIdFactory> id_factory_;
 
   // UI thread.
   BrowserThreadImpl ui_thread_;
diff --git a/content/browser/download/download_file_unittest.cc b/content/browser/download/download_file_unittest.cc
index 4855d44..9ca77c5 100644
--- a/content/browser/download/download_file_unittest.cc
+++ b/content/browser/download/download_file_unittest.cc
@@ -8,8 +8,6 @@
 #include "content/browser/browser_thread_impl.h"
 #include "content/browser/download/download_create_info.h"
 #include "content/browser/download/download_file_impl.h"
-#include "content/browser/download/download_id.h"
-#include "content/browser/download/download_id_factory.h"
 #include "content/browser/download/download_request_handle.h"
 #include "content/browser/download/download_status_updater.h"
 #include "content/browser/download/mock_download_manager.h"
@@ -22,6 +20,7 @@
 using content::BrowserThread;
 using content::BrowserThreadImpl;
 using content::DownloadFile;
+using content::DownloadId;
 using content::DownloadManager;
 
 DownloadId::Domain kValidIdDomain = "valid DownloadId::Domain";
@@ -42,7 +41,6 @@ class DownloadFileTest : public testing::Test {
   // calling Release() on |download_manager_| won't ever result in its
   // destructor being called and we get a leak.
   DownloadFileTest() :
-      id_factory_(new DownloadIdFactory(kValidIdDomain)),
       ui_thread_(BrowserThread::UI, &loop_),
       file_thread_(BrowserThread::FILE, &loop_) {
   }
@@ -113,7 +111,6 @@ class DownloadFileTest : public testing::Test {
 
  private:
   MessageLoop loop_;
-  scoped_refptr<DownloadIdFactory> id_factory_;
   // UI thread.
   BrowserThreadImpl ui_thread_;
   // File thread to satisfy debug checks in DownloadFile.
diff --git a/content/browser/download/download_id.cc b/content/browser/download/download_id.cc
deleted file mode 100644
index 8cd7b0e..0000000
--- a/content/browser/download/download_id.cc
+++ /dev/null
@@ -1,16 +0,0 @@
-// 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 <string>
-
-#include "base/stringprintf.h"
-#include "content/browser/download/download_id.h"
-
-std::string DownloadId::DebugString() const {
-  return base::StringPrintf("%p:%d", domain_, local_id_);
-}
-
-std::ostream& operator<<(std::ostream& out, const DownloadId& global_id) {
-  return out << global_id.DebugString();
-}
diff --git a/content/browser/download/download_id_factory.cc b/content/browser/download/download_id_factory.cc
deleted file mode 100644
index 6b0797f..0000000
--- a/content/browser/download/download_id_factory.cc
+++ /dev/null
@@ -1,17 +0,0 @@
-// 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_id_factory.h"
-
-#include "content/browser/download/download_id.h"
-
-DownloadIdFactory::DownloadIdFactory(DownloadId::Domain domain)
-  : domain_(domain),
-    next_id_(0) {
-}
-
-DownloadId DownloadIdFactory::GetNextId() {
-  base::AutoLock lock(lock_);
-  return DownloadId(domain_, next_id_++);
-}
diff --git a/content/browser/download/download_id_factory.h b/content/browser/download/download_id_factory.h
deleted file mode 100644
index 729c752..0000000
--- a/content/browser/download/download_id_factory.h
+++ /dev/null
@@ -1,31 +0,0 @@
-// 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.
-
-#ifndef CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ID_FACTORY_H_
-#define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ID_FACTORY_H_
-#pragma once
-
-#include "base/memory/ref_counted.h"
-#include "base/synchronization/lock.h"
-#include "content/browser/download/download_id.h"
-#include "content/public/browser/browser_thread.h"
-
-class CONTENT_EXPORT DownloadIdFactory
-    : public base::RefCountedThreadSafe<DownloadIdFactory> {
- public:
-  // TODO(benjhayden): Instantiate with an explicit next id counter read from
-  // persistent storage.
-  explicit DownloadIdFactory(DownloadId::Domain domain);
-
-  DownloadId GetNextId();
-
- private:
-  DownloadId::Domain domain_;
-  int next_id_;
-  base::Lock lock_;
-
-  DISALLOW_COPY_AND_ASSIGN(DownloadIdFactory);
-};
-
-#endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ID_FACTORY_H_
diff --git a/content/browser/download/download_id_unittest.cc b/content/browser/download/download_id_unittest.cc
index 18f157f..5a80a39 100644
--- a/content/browser/download/download_id_unittest.cc
+++ b/content/browser/download/download_id_unittest.cc
@@ -2,7 +2,7 @@
 // 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_id.h"
+#include "content/public/browser/download_id.h"
 
 #include <algorithm>
 #include <map>
@@ -17,6 +17,7 @@
 
 using content::BrowserThread;
 using content::BrowserThreadImpl;
+using content::DownloadId;
 using content::DownloadManager;
 
 class DownloadIdTest : public testing::Test {
diff --git a/content/browser/download/download_item_impl.cc b/content/browser/download/download_item_impl.cc
index cc48515..2d1ad6d 100644
--- a/content/browser/download/download_item_impl.cc
+++ b/content/browser/download/download_item_impl.cc
@@ -19,7 +19,6 @@
 #include "base/utf_string_conversions.h"
 #include "content/browser/download/download_create_info.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"
@@ -32,6 +31,7 @@
 
 using content::BrowserThread;
 using content::DownloadFile;
+using content::DownloadId;
 using content::DownloadItem;
 using content::DownloadManager;
 using content::WebContents;
diff --git a/content/browser/download/download_item_impl.h b/content/browser/download/download_item_impl.h
index 87c7d31..c3d3119 100644
--- a/content/browser/download/download_item_impl.h
+++ b/content/browser/download/download_item_impl.h
@@ -14,9 +14,9 @@
 #include "base/observer_list.h"
 #include "base/time.h"
 #include "base/timer.h"
-#include "content/browser/download/download_id.h"
 #include "content/browser/download/download_request_handle.h"
 #include "content/common/content_export.h"
+#include "content/public/browser/download_id.h"
 #include "content/public/browser/download_item.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/net_errors.h"
@@ -82,7 +82,7 @@ class CONTENT_EXPORT DownloadItemImpl : public content::DownloadItem {
 
   // Constructing from persistent store:
   DownloadItemImpl(Delegate* delegate,
-                   DownloadId download_id,
+                   content::DownloadId download_id,
                    const DownloadPersistentStoreInfo& info);
 
   // Constructing for a regular download.
@@ -97,7 +97,7 @@ class CONTENT_EXPORT DownloadItemImpl : public content::DownloadItem {
                    const FilePath& path,
                    const GURL& url,
                    bool is_otr,
-                   DownloadId download_id);
+                   content::DownloadId download_id);
 
   virtual ~DownloadItemImpl();
 
@@ -161,7 +161,7 @@ class CONTENT_EXPORT DownloadItemImpl : public content::DownloadItem {
   virtual int64 GetReceivedBytes() const OVERRIDE;
   virtual const std::string& GetHashState() const OVERRIDE;
   virtual int32 GetId() const OVERRIDE;
-  virtual DownloadId GetGlobalId() const OVERRIDE;
+  virtual content::DownloadId GetGlobalId() const OVERRIDE;
   virtual base::Time GetStartTime() const OVERRIDE;
   virtual base::Time GetEndTime() const OVERRIDE;
   virtual void SetDbHandle(int64 handle) OVERRIDE;
@@ -240,7 +240,7 @@ class CONTENT_EXPORT DownloadItemImpl : public content::DownloadItem {
   scoped_ptr<DownloadRequestHandleInterface> request_handle_;
 
   // Download ID assigned by DownloadResourceHandler.
-  DownloadId download_id_;
+  content::DownloadId download_id_;
 
   // Full path to the downloaded or downloading file.
   FilePath full_path_;
diff --git a/content/browser/download/download_manager_impl.cc b/content/browser/download/download_manager_impl.cc
index cc8d55c..2276afc 100644
--- a/content/browser/download/download_manager_impl.cc
+++ b/content/browser/download/download_manager_impl.cc
@@ -19,7 +19,6 @@
 #include "build/build_config.h"
 #include "content/browser/download/download_create_info.h"
 #include "content/browser/download/download_file_manager.h"
-#include "content/browser/download/download_id_factory.h"
 #include "content/browser/download/download_item_impl.h"
 #include "content/browser/download/download_persistent_store_info.h"
 #include "content/browser/download/download_stats.h"
@@ -49,6 +48,7 @@
 #define CHECK_96627 CHECK
 
 using content::BrowserThread;
+using content::DownloadId;
 using content::DownloadItem;
 using content::WebContents;
 
@@ -116,16 +116,14 @@ namespace content {
 // static
 DownloadManager* DownloadManager::Create(
       content::DownloadManagerDelegate* delegate,
-      DownloadIdFactory* id_factory,
       DownloadStatusUpdater* status_updater) {
-  return new DownloadManagerImpl(delegate, id_factory, status_updater);
+  return new DownloadManagerImpl(delegate, status_updater);
 }
 
 }  // namespace content
 
 DownloadManagerImpl::DownloadManagerImpl(
     content::DownloadManagerDelegate* delegate,
-    DownloadIdFactory* id_factory,
     DownloadStatusUpdater* status_updater)
         : shutdown_needed_(false),
           browser_context_(NULL),
@@ -134,7 +132,6 @@ DownloadManagerImpl::DownloadManagerImpl(
                           ? status_updater->AsWeakPtr()
                           : base::WeakPtr<DownloadStatusUpdater>()),
           delegate_(delegate),
-          id_factory_(id_factory),
           largest_db_handle_in_history_(DownloadItem::kUninitializedHandle) {
   // NOTE(benjhayden): status_updater may be NULL when using
   // TestingBrowserProcess.
@@ -147,7 +144,7 @@ DownloadManagerImpl::~DownloadManagerImpl() {
 }
 
 DownloadId DownloadManagerImpl::GetNextId() {
-  return id_factory_->GetNextId();
+  return delegate_->GetNextId();
 }
 
 bool DownloadManagerImpl::ShouldOpenDownload(DownloadItem* item) {
diff --git a/content/browser/download/download_manager_impl.h b/content/browser/download/download_manager_impl.h
index 3a3253b..b69753d 100644
--- a/content/browser/download/download_manager_impl.h
+++ b/content/browser/download/download_manager_impl.h
@@ -22,7 +22,6 @@
 #include "content/common/content_export.h"
 #include "content/public/browser/download_manager.h"
 
-class DownloadIdFactory;
 class DownloadStatusUpdater;
 
 namespace content {
@@ -35,7 +34,6 @@ class CONTENT_EXPORT DownloadManagerImpl
       public DownloadStatusUpdaterDelegate {
  public:
   DownloadManagerImpl(content::DownloadManagerDelegate* delegate,
-                      DownloadIdFactory* id_factory,
                       DownloadStatusUpdater* status_updater);
 
   // content::DownloadManager functions.
@@ -153,8 +151,8 @@ class CONTENT_EXPORT DownloadManagerImpl
   // Show the download in the browser.
   void ShowDownloadInBrowser(content::DownloadItem* download);
 
-  // Get next download id from factory.
-  DownloadId GetNextId();
+  // Get next download id.
+  content::DownloadId GetNextId();
 
   // Called on the FILE thread to check the existence of a downloaded file.
   void CheckForFileRemovalOnFileThread(int64 db_handle, const FilePath& path);
@@ -270,8 +268,6 @@ class CONTENT_EXPORT DownloadManagerImpl
   // Allows an embedder to control behavior. Guaranteed to outlive this object.
   content::DownloadManagerDelegate* delegate_;
 
-  DownloadIdFactory* id_factory_;
-
   // TODO(rdsmith): Remove when http://crbug.com/85408 is fixed.
   // For debugging only.
   int64 largest_db_handle_in_history_;
diff --git a/content/browser/download/download_resource_handler.cc b/content/browser/download/download_resource_handler.cc
index 34d072d..43a2e17 100644
--- a/content/browser/download/download_resource_handler.cc
+++ b/content/browser/download/download_resource_handler.cc
@@ -14,6 +14,7 @@
 #include "content/browser/download/download_buffer.h"
 #include "content/browser/download/download_create_info.h"
 #include "content/browser/download/download_file_manager.h"
+#include "content/browser/download/download_manager_impl.h"
 #include "content/browser/download/download_request_handle.h"
 #include "content/browser/download/download_stats.h"
 #include "content/browser/download/interrupt_reasons.h"
@@ -21,6 +22,7 @@
 #include "content/browser/renderer_host/resource_dispatcher_host_request_info.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/download_item.h"
+#include "content/public/browser/download_manager_delegate.h"
 #include "content/public/common/resource_response.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
@@ -28,7 +30,9 @@
 #include "net/url_request/url_request_context.h"
 
 using content::BrowserThread;
+using content::DownloadId;
 using content::DownloadItem;
+using content::DownloadManager;
 
 DownloadResourceHandler::DownloadResourceHandler(
     ResourceDispatcherHost* rdh,
@@ -36,13 +40,12 @@ DownloadResourceHandler::DownloadResourceHandler(
     int render_view_id,
     int request_id,
     const GURL& url,
-    DownloadId dl_id,
     DownloadFileManager* download_file_manager,
     net::URLRequest* request,
     bool save_as,
     const DownloadResourceHandler::OnStartedCallback& started_cb,
     const DownloadSaveInfo& save_info)
-    : download_id_(dl_id),
+    : download_id_(DownloadId::Invalid()),
       global_id_(render_process_host_id, request_id),
       render_view_id_(render_view_id),
       content_length_(0),
@@ -56,7 +59,6 @@ DownloadResourceHandler::DownloadResourceHandler(
       is_paused_(false),
       last_buffer_size_(0),
       bytes_read_(0) {
-  DCHECK(dl_id.IsValid());
   download_stats::RecordDownloadCount(download_stats::UNTHROTTLED_COUNT);
 }
 
@@ -79,7 +81,6 @@ bool DownloadResourceHandler::OnRequestRedirected(
 bool DownloadResourceHandler::OnResponseStarted(
     int request_id,
     content::ResourceResponse* response) {
-  DCHECK(download_id_.IsValid());
   VLOG(20) << __FUNCTION__ << "()" << DebugString()
            << " request_id = " << request_id;
   download_start_time_ = base::TimeTicks::Now();
@@ -99,15 +100,13 @@ bool DownloadResourceHandler::OnResponseStarted(
   // Deleted in DownloadManager.
   DownloadCreateInfo* info = new DownloadCreateInfo(FilePath(), GURL(),
       base::Time::Now(), 0, content_length_, DownloadItem::IN_PROGRESS,
-      download_id_, request_info->has_user_gesture(),
-      request_info->transition_type());
+      request_info->has_user_gesture(), request_info->transition_type());
   info->url_chain = request_->url_chain();
   info->referrer_url = GURL(request_->referrer());
   info->start_time = base::Time::Now();
   info->received_bytes = save_info_.offset;
   info->total_bytes = content_length_;
   info->state = DownloadItem::IN_PROGRESS;
-  info->download_id = download_id_;
   info->has_user_gesture = request_info->has_user_gesture();
   info->content_disposition = content_disposition_;
   info->mime_type = response->mime_type;
@@ -128,8 +127,6 @@ bool DownloadResourceHandler::OnResponseStarted(
       info->etag = etag;
   }
 
-  CallStartedCB(net::OK);
-
   std::string content_type_header;
   if (!response->headers ||
       !response->headers->GetMimeType(&content_type_header))
@@ -147,23 +144,26 @@ bool DownloadResourceHandler::OnResponseStarted(
       save_as_ && save_info_.file_path.empty();
   info->referrer_charset = request_->context()->referrer_charset();
   info->save_info = save_info_;
+
+
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
-      base::Bind(&DownloadFileManager::StartDownload,
-                 download_file_manager_, info, request_handle));
+      base::Bind(&DownloadResourceHandler::StartOnUIThread, this,
+                 info, request_handle));
 
-  // We can't start saving the data before we create the file on disk.
-  // The request will be un-paused in DownloadFileManager::CreateDownloadFile.
+  // We can't start saving the data before we create the file on disk and have a
+  // download id. The request will be un-paused in
+  // DownloadFileManager::CreateDownloadFile.
   rdh_->PauseRequest(global_id_.child_id, global_id_.request_id, true);
 
   return true;
 }
 
-void DownloadResourceHandler::CallStartedCB(net::Error error) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+void DownloadResourceHandler::CallStartedCB(DownloadId id, net::Error error) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (started_cb_.is_null())
     return;
-  started_cb_.Run(download_id_, error);
+  started_cb_.Run(id, error);
   started_cb_.Reset();
 }
 
@@ -233,6 +233,20 @@ bool DownloadResourceHandler::OnResponseCompleted(
     int request_id,
     const net::URLRequestStatus& status,
     const std::string& security_info) {
+  if (!download_id_.IsValid()) {
+    // We got cancelled before the task which sets the id ran on the IO thread.
+    // Wait for it.
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(base::IgnoreResult(&BrowserThread::PostTask),
+            BrowserThread::IO, FROM_HERE,
+            base::Bind(base::IgnoreResult(
+                &DownloadResourceHandler::OnResponseCompleted), this,
+                request_id, status, security_info)));
+                                  
+    return true;
+  }
+
   VLOG(20) << __FUNCTION__ << "()" << DebugString()
            << " request_id = " << request_id
            << " status.status() = " << status.status()
@@ -259,8 +273,12 @@ bool DownloadResourceHandler::OnResponseCompleted(
 
   download_stats::RecordAcceptsRanges(accept_ranges_, bytes_read_);
 
-  if (!download_id_.IsValid())
-    CallStartedCB(error_code);
+  // If the callback was already run on the UI thread, this will be a noop.
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&DownloadResourceHandler::CallStartedCB, this,
+                 download_id_, error_code));
+
   // We transfer ownership to |DownloadFileManager| to delete |buffer_|,
   // so that any functions queued up on the FILE thread are executed
   // before deletion.
@@ -278,6 +296,29 @@ void DownloadResourceHandler::OnRequestClosed() {
                       base::TimeTicks::Now() - download_start_time_);
 }
 
+void DownloadResourceHandler::StartOnUIThread(DownloadCreateInfo* info,
+                                              DownloadRequestHandle handle) {
+  DownloadManager* download_manager = handle.GetDownloadManager();
+  if (!download_manager)
+    return;  // NULL in unittests
+  info->download_id = download_manager->delegate()->GetNextId();
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&DownloadResourceHandler::set_download_id, this,
+                 info->download_id));
+  CallStartedCB(info->download_id, net::OK);
+  // It's safe to continue on with download initiation before we have
+  // confirmation that that download_id_ has been set on the IO thread, as any
+  // messages generated by the UI thread that affect the IO thread will be
+  // behind the message posted above.
+  download_file_manager_->StartDownload(info, handle);
+}
+
+void DownloadResourceHandler::set_download_id(content::DownloadId id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  download_id_ = id;
+}
+
 // If the content-length header is not present (or contains something other
 // than numbers), the incoming content_length is -1 (unknown size).
 // Set the content length to 0 to indicate unknown size to DownloadManager.
diff --git a/content/browser/download/download_resource_handler.h b/content/browser/download/download_resource_handler.h
index 5425c51..b651c48 100644
--- a/content/browser/download/download_resource_handler.h
+++ b/content/browser/download/download_resource_handler.h
@@ -11,14 +11,16 @@
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/timer.h"
-#include "content/browser/download/download_id.h"
 #include "content/browser/download/download_types.h"
 #include "content/browser/renderer_host/resource_handler.h"
+#include "content/public/browser/download_id.h"
 #include "content/public/browser/global_request_id.h"
 #include "net/base/net_errors.h"
 
 class DownloadFileManager;
+class DownloadRequestHandle;
 class ResourceDispatcherHost;
+struct DownloadCreateInfo;
 
 namespace content {
 class DownloadBuffer;
@@ -31,18 +33,17 @@ class URLRequest;
 // Forwards data to the download thread.
 class DownloadResourceHandler : public ResourceHandler {
  public:
-  typedef base::Callback<void(DownloadId, net::Error)>
-    OnStartedCallback;
+  typedef base::Callback<void(content::DownloadId, net::Error)>
+      OnStartedCallback;
 
   static const size_t kLoadsToWrite = 100;  // number of data buffers queued
 
-  // started_cb will be called exactly once.
+  // started_cb will be called exactly once on the UI thread.
   DownloadResourceHandler(ResourceDispatcherHost* rdh,
                           int render_process_host_id,
                           int render_view_id,
                           int request_id,
                           const GURL& url,
-                          DownloadId dl_id,
                           DownloadFileManager* download_file_manager,
                           net::URLRequest* request,
                           bool save_as,
@@ -97,9 +98,14 @@ class DownloadResourceHandler : public ResourceHandler {
   virtual ~DownloadResourceHandler();
 
   void StartPauseTimer();
-  void CallStartedCB(net::Error error);
+  void CallStartedCB(content::DownloadId id, net::Error error);
 
-  DownloadId download_id_;
+  // Generates a DownloadId and calls DownloadFileManager.
+  void StartOnUIThread(DownloadCreateInfo* info,
+                       DownloadRequestHandle handle);
+  void set_download_id(content::DownloadId id);
+
+  content::DownloadId download_id_;
   content::GlobalRequestID global_id_;
   int render_view_id_;
   scoped_refptr<net::IOBuffer> read_buffer_;
@@ -108,6 +114,7 @@ class DownloadResourceHandler : public ResourceHandler {
   DownloadFileManager* download_file_manager_;
   net::URLRequest* request_;
   bool save_as_;  // Request was initiated via "Save As" by the user.
+  // This is used only on the UI thread.
   OnStartedCallback started_cb_;
   DownloadSaveInfo save_info_;
   scoped_refptr<content::DownloadBuffer> buffer_;
diff --git a/content/browser/download/mock_download_file.h b/content/browser/download/mock_download_file.h
index 2e97b04..6aff4da 100644
--- a/content/browser/download/mock_download_file.h
+++ b/content/browser/download/mock_download_file.h
@@ -11,9 +11,8 @@
 
 #include "base/file_path.h"
 #include "base/memory/ref_counted.h"
-#include "content/browser/download/download_id.h"
-#include "content/browser/download/download_request_handle.h"
 #include "content/public/browser/download_file.h"
+#include "content/public/browser/download_id.h"
 #include "content/public/browser/download_manager.h"
 #include "net/base/net_errors.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ -43,7 +42,7 @@ class MockDownloadFile : virtual public content::DownloadFile {
   MOCK_METHOD0(CancelDownloadRequest, void());
   MOCK_CONST_METHOD0(Id, int());
   MOCK_METHOD0(GetDownloadManager, content::DownloadManager*());
-  MOCK_CONST_METHOD0(GlobalId, const DownloadId&());
+  MOCK_CONST_METHOD0(GlobalId, const content::DownloadId&());
   MOCK_CONST_METHOD0(DebugString, std::string());
 };
 
diff --git a/content/browser/download/mock_download_item.h b/content/browser/download/mock_download_item.h
index 42d25b8..1212ee5 100644
--- a/content/browser/download/mock_download_item.h
+++ b/content/browser/download/mock_download_item.h
@@ -8,9 +8,9 @@
 #include <string>
 #include <vector>
 
-#include "content/browser/download/download_id.h"
 #include "content/browser/download/download_persistent_store_info.h"
 #include "content/browser/download/interrupt_reasons.h"
+#include "content/public/browser/download_id.h"
 #include "content/public/browser/download_item.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -73,7 +73,7 @@ class MockDownloadItem : public content::DownloadItem {
   MOCK_CONST_METHOD0(GetHashState, const std::string&());
   MOCK_CONST_METHOD0(GetHash, const std::string&());
   MOCK_CONST_METHOD0(GetId, int32());
-  MOCK_CONST_METHOD0(GetGlobalId, DownloadId());
+  MOCK_CONST_METHOD0(GetGlobalId, content::DownloadId());
   MOCK_CONST_METHOD0(GetStartTime, base::Time());
   MOCK_CONST_METHOD0(GetEndTime, base::Time());
   MOCK_METHOD1(SetDbHandle, void(int64));
diff --git a/content/browser/download/mock_download_manager.h b/content/browser/download/mock_download_manager.h
index cf08d82..6e9be3f 100644
--- a/content/browser/download/mock_download_manager.h
+++ b/content/browser/download/mock_download_manager.h
@@ -6,10 +6,9 @@
 #define CONTENT_BROWSER_DOWNLOAD_MOCK_DOWNLOAD_MANAGER_H_
 #pragma once
 
-#include "content/browser/download/download_id.h"
-#include "content/browser/download/download_id_factory.h"
 #include "content/browser/download/download_request_handle.h"
 #include "content/browser/download/download_types.h"
+#include "content/public/browser/download_id.h"
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/download_manager.h"
 #include "content/public/browser/download_query.h"
diff --git a/content/browser/download/mock_download_manager_delegate.h b/content/browser/download/mock_download_manager_delegate.h
index 1fb62cb..ff48765 100644
--- a/content/browser/download/mock_download_manager_delegate.h
+++ b/content/browser/download/mock_download_manager_delegate.h
@@ -9,6 +9,7 @@
 #include "base/compiler_specific.h"
 #include "base/file_path.h"
 #include "content/browser/download/download_types.h"
+#include "content/public/browser/download_id.h"
 #include "content/public/browser/download_manager_delegate.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -25,6 +26,7 @@ class MockDownloadManagerDelegate : public content::DownloadManagerDelegate {
   // DownloadManagerDelegate functions:
   MOCK_METHOD1(SetDownloadManager, void(content::DownloadManager* dm));
   MOCK_METHOD0(Shutdown, void());
+  MOCK_METHOD0(GetNextId, content::DownloadId());
   MOCK_METHOD1(ShouldStartDownload, bool(int32 download_id));
   MOCK_METHOD3(ChooseDownloadPath, void(content::WebContents* web_contents,
                                         const FilePath& suggested_path,
diff --git a/content/browser/renderer_host/buffered_resource_handler.cc b/content/browser/renderer_host/buffered_resource_handler.cc
index 871f003..f06e475 100644
--- a/content/browser/renderer_host/buffered_resource_handler.cc
+++ b/content/browser/renderer_host/buffered_resource_handler.cc
@@ -10,7 +10,6 @@
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
-#include "content/browser/download/download_id_factory.h"
 #include "content/browser/download/download_resource_handler.h"
 #include "content/browser/download/download_stats.h"
 #include "content/browser/download/download_types.h"
@@ -303,15 +302,12 @@ bool BufferedResourceHandler::CompleteResponseStarted(int request_id) {
 
     info->set_is_download(true);
 
-    DownloadId dl_id = info->context()->download_id_factory()->GetNextId();
-
     scoped_refptr<ResourceHandler> handler(
       new DownloadResourceHandler(host_,
                                   info->child_id(),
                                   info->route_id(),
                                   info->request_id(),
                                   request_->url(),
-                                  dl_id,
                                   host_->download_file_manager(),
                                   request_,
                                   false,
diff --git a/content/browser/renderer_host/resource_dispatcher_host.cc b/content/browser/renderer_host/resource_dispatcher_host.cc
index b0b29b5..bbbc040 100644
--- a/content/browser/renderer_host/resource_dispatcher_host.cc
+++ b/content/browser/renderer_host/resource_dispatcher_host.cc
@@ -27,7 +27,6 @@
 #include "content/browser/chrome_blob_storage_context.h"
 #include "content/browser/cross_site_request_manager.h"
 #include "content/browser/download/download_file_manager.h"
-#include "content/browser/download/download_id_factory.h"
 #include "content/browser/download/download_resource_handler.h"
 #include "content/browser/download/save_file_manager.h"
 #include "content/browser/download/save_file_resource_handler.h"
@@ -877,7 +876,7 @@ void ResourceDispatcherHost::OnDidLoadResourceFromMemoryCache(
 }
 
 // We are explicitly forcing the download of 'url'.
-void ResourceDispatcherHost::BeginDownload(
+net::Error ResourceDispatcherHost::BeginDownload(
     scoped_ptr<net::URLRequest> request,
     const DownloadSaveInfo& save_info,
     bool prompt_for_save_location,
@@ -885,14 +884,9 @@ void ResourceDispatcherHost::BeginDownload(
     int child_id,
     int route_id,
     const content::ResourceContext& context) {
-  // If DownloadResourceHandler is not begun, then started_cb must be called
-  // here in order to satisfy its semantics.
-  if (is_shutdown_) {
-    if (!started_cb.is_null())
-      started_cb.Run(DownloadId::Invalid(), net::ERR_INSUFFICIENT_RESOURCES);
-    // Time and RDH are resources that are running out.
-    return;
-  }
+  if (is_shutdown_)
+    return net::ERR_INSUFFICIENT_RESOURCES;
+
   const GURL& url = request->original_url();
   const net::URLRequestContext* request_context = context.request_context();
   request->set_referrer(MaybeStripReferrer(GURL(request->referrer())).spec());
@@ -905,22 +899,17 @@ void ResourceDispatcherHost::BeginDownload(
           CanRequestURL(child_id, url)) {
     VLOG(1) << "Denied unauthorized download request for "
             << url.possibly_invalid_spec();
-    if (!started_cb.is_null())
-      started_cb.Run(DownloadId::Invalid(), net::ERR_ACCESS_DENIED);
-    return;
+    return net::ERR_ACCESS_DENIED;
   }
 
   request_id_--;
 
-  DownloadId dl_id = context.download_id_factory()->GetNextId();
-
   scoped_refptr<ResourceHandler> handler(
       new DownloadResourceHandler(this,
                                   child_id,
                                   route_id,
                                   request_id_,
                                   url,
-                                  dl_id,
                                   download_file_manager_.get(),
                                   request.get(),
                                   prompt_for_save_location,
@@ -936,9 +925,7 @@ void ResourceDispatcherHost::BeginDownload(
   if (!request_context->job_factory()->IsHandledURL(url)) {
     VLOG(1) << "Download request for unsupported protocol: "
             << url.possibly_invalid_spec();
-    if (!started_cb.is_null())
-      started_cb.Run(DownloadId::Invalid(), net::ERR_ACCESS_DENIED);
-    return;
+    return net::ERR_ACCESS_DENIED;
   }
 
   ResourceDispatcherHostRequestInfo* extra_info =
@@ -946,6 +933,8 @@ void ResourceDispatcherHost::BeginDownload(
   SetRequestInfo(request.get(), extra_info);  // Request takes ownership.
 
   BeginRequestInternal(request.release());
+
+  return net::OK;
 }
 
 // This function is only used for saving feature.
diff --git a/content/browser/renderer_host/resource_dispatcher_host.h b/content/browser/renderer_host/resource_dispatcher_host.h
index c2275ad..35aea36 100644
--- a/content/browser/renderer_host/resource_dispatcher_host.h
+++ b/content/browser/renderer_host/resource_dispatcher_host.h
@@ -81,10 +81,10 @@ class CONTENT_EXPORT ResourceDispatcherHost : public net::URLRequest::Delegate {
                          bool* message_was_ok);
 
   // Initiates a download by explicit request of the renderer, e.g. due to
-  // alt-clicking a link.  If |request| is malformed or not permitted or the RDH
-  // is shutting down, then |started_cb| will be called immediately. There is no
-  // situation in which |started_cb| will never be called.
-  void BeginDownload(
+  // alt-clicking a link.  If the download is started, |started_cb| will be
+  // called on the UI thread with the DownloadId; otherwise an error code will
+  // be returned.
+  net::Error BeginDownload(
       scoped_ptr<net::URLRequest> request,
       const DownloadSaveInfo& save_info,
       bool prompt_for_save_location,
diff --git a/content/browser/renderer_host/resource_dispatcher_host_unittest.cc b/content/browser/renderer_host/resource_dispatcher_host_unittest.cc
index 8867bad..6657605 100644
--- a/content/browser/renderer_host/resource_dispatcher_host_unittest.cc
+++ b/content/browser/renderer_host/resource_dispatcher_host_unittest.cc
@@ -12,8 +12,6 @@
 #include "base/process_util.h"
 #include "content/browser/browser_thread_impl.h"
 #include "content/browser/child_process_security_policy.h"
-#include "content/browser/download/download_id.h"
-#include "content/browser/download/download_id_factory.h"
 #include "content/browser/mock_resource_context.h"
 #include "content/browser/renderer_host/dummy_resource_handler.h"
 #include "content/browser/renderer_host/layered_resource_handler.h"
@@ -1238,12 +1236,6 @@ TEST_F(ResourceDispatcherHostTest, ForbiddenDownload) {
   EXPECT_EQ(net::ERR_FILE_NOT_FOUND, status.error());
 }
 
-namespace {
-DownloadId MockNextDownloadId() {
-  return DownloadId(reinterpret_cast<DownloadManager*>(0xFFFFFFFF), 0);
-}
-}
-
 // Test for http://crbug.com/76202 .  We don't want to destroy a
 // download request prematurely when processing a cancellation from
 // the renderer.
@@ -1264,10 +1256,6 @@ TEST_F(ResourceDispatcherHostTest, IgnoreCancelForDownloads) {
   HandleScheme("http");
 
   MakeTestRequest(render_view_id, request_id, GURL("http://example.com/blah"));
-  scoped_refptr<DownloadIdFactory> id_factory(
-      new DownloadIdFactory("valid DownloadId::Domain"));
-  content::MockResourceContext::GetInstance()->set_download_id_factory(
-      id_factory);
   // Return some data so that the request is identified as a download
   // and the proper resource handlers are created.
   EXPECT_TRUE(net::URLRequestTestJob::ProcessOnePendingMessage());
@@ -1303,10 +1291,6 @@ TEST_F(ResourceDispatcherHostTest, CancelRequestsForContext) {
   HandleScheme("http");
 
   MakeTestRequest(render_view_id, request_id, GURL("http://example.com/blah"));
-  scoped_refptr<DownloadIdFactory> id_factory(
-      new DownloadIdFactory("valid DownloadId::Domain"));
-  content::MockResourceContext::GetInstance()->set_download_id_factory(
-      id_factory);
   // Return some data so that the request is identified as a download
   // and the proper resource handlers are created.
   EXPECT_TRUE(net::URLRequestTestJob::ProcessOnePendingMessage());
diff --git a/content/browser/resource_context.cc b/content/browser/resource_context.cc
index 6eb7646..9704246 100644
--- a/content/browser/resource_context.cc
+++ b/content/browser/resource_context.cc
@@ -21,7 +21,6 @@ ResourceContext::ResourceContext()
       quota_manager_(NULL),
       host_zoom_map_(NULL),
       media_observer_(NULL),
-      download_id_factory_(NULL),
       media_stream_manager_(NULL),
       audio_manager_(NULL) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
@@ -155,18 +154,6 @@ void ResourceContext::set_media_observer(MediaObserver* media_observer) {
   media_observer_ = media_observer;
 }
 
-DownloadIdFactory* ResourceContext::download_id_factory() const {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  EnsureInitialized();
-  return download_id_factory_;
-}
-
-void ResourceContext::set_download_id_factory(
-    DownloadIdFactory* download_id_factory) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  download_id_factory_ = download_id_factory;
-}
-
 media_stream::MediaStreamManager*
 ResourceContext::media_stream_manager() const {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
diff --git a/content/browser/resource_context.h b/content/browser/resource_context.h
index 21f36de..22803e3 100644
--- a/content/browser/resource_context.h
+++ b/content/browser/resource_context.h
@@ -15,7 +15,6 @@
 class AudioManager;
 class ChromeAppCacheService;
 class ChromeBlobStorageContext;
-class DownloadIdFactory;
 class HostZoomMap;
 class MediaObserver;
 namespace fileapi {
@@ -77,9 +76,6 @@ class CONTENT_EXPORT ResourceContext {
   MediaObserver* media_observer() const;
   void set_media_observer(MediaObserver* media_observer);
 
-  DownloadIdFactory* download_id_factory() const;
-  void set_download_id_factory(DownloadIdFactory* download_id_factory);
-
   media_stream::MediaStreamManager* media_stream_manager() const;
   void set_media_stream_manager(
       media_stream::MediaStreamManager* media_stream_manager);
@@ -102,7 +98,6 @@ class CONTENT_EXPORT ResourceContext {
   quota::QuotaManager* quota_manager_;
   HostZoomMap* host_zoom_map_;
   MediaObserver* media_observer_;
-  DownloadIdFactory* download_id_factory_;
   media_stream::MediaStreamManager* media_stream_manager_;
   AudioManager* audio_manager_;
 
diff --git a/content/content_browser.gypi b/content/content_browser.gypi
index 0828aee..123c962 100644
--- a/content/content_browser.gypi
+++ b/content/content_browser.gypi
@@ -45,6 +45,7 @@
     'public/browser/devtools_agent_host_registry.h',
     'public/browser/devtools_client_host.h',
     'public/browser/download_danger_type.h',
+    'public/browser/download_id.h',
     'public/browser/devtools_frontend_host_delegate.h',
     'public/browser/devtools_http_handler.h',
     'public/browser/devtools_http_handler_delegate.h',
@@ -195,10 +196,6 @@
     'browser/download/download_file_impl.h',
     'browser/download/download_file_manager.cc',
     'browser/download/download_file_manager.h',
-    'browser/download/download_id.cc',
-    'browser/download/download_id.h',
-    'browser/download/download_id_factory.cc',
-    'browser/download/download_id_factory.h',
     'browser/download/download_item_impl.cc',
     'browser/download/download_item_impl.h',
     'browser/download/download_manager_impl.cc',
diff --git a/content/public/browser/download_file.h b/content/public/browser/download_file.h
index 4a84282..b242a99 100644
--- a/content/public/browser/download_file.h
+++ b/content/public/browser/download_file.h
@@ -10,8 +10,8 @@
 
 #include "base/basictypes.h"
 #include "base/file_path.h"
-#include "content/browser/download/download_id.h"
 #include "content/common/content_export.h"
+#include "content/public/browser/download_id.h"
 #include "net/base/net_errors.h"
 
 namespace content {
diff --git a/content/browser/download/download_id.h b/content/public/browser/download_id.h
index d9726bf..96ecc63 100644
--- a/content/browser/download/download_id.h
+++ b/content/public/browser/download_id.h
@@ -2,16 +2,19 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ID_H_
-#define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ID_H_
+#ifndef CONTENT_PUBLIC_BROWSER_DOWNLOAD_ID_H_
+#define CONTENT_PUBLIC_BROWSER_DOWNLOAD_ID_H_
 #pragma once
 
 #include <iosfwd>
 #include <string>
 
 #include "base/hash_tables.h"
+#include "base/stringprintf.h"
 #include "content/common/content_export.h"
 
+namespace content {
+
 // DownloadId combines per-profile Download ids with an indication of which
 // profile in order to be globally unique. DownloadIds are not persistent across
 // sessions, but their local() field is.
@@ -59,7 +62,9 @@ class DownloadId {
            (static_cast<size_t>(local_id_) << (4 * sizeof(size_t)));
   }
 
-  std::string DebugString() const;
+  std::string DebugString() const {
+    return base::StringPrintf("%p:%d", domain_, local_id_);
+  }
 
  private:
   Domain domain_;
@@ -69,22 +74,28 @@ class DownloadId {
   // Allow copy and assign.
 };
 
+}  // namespace content
+
 // Allow logging DownloadIds. Looks like "0x01234567:42".
 CONTENT_EXPORT std::ostream& operator<<(std::ostream& out,
-                                        const DownloadId& global_id);
+                                        const content::DownloadId& global_id);
+inline std::ostream& operator<<(std::ostream& out,
+                                const content::DownloadId& global_id) {
+  return out << global_id.DebugString();
+}
 
 // Allow using DownloadIds as keys in hash_maps.
 namespace BASE_HASH_NAMESPACE {
 #if defined(COMPILER_GCC)
-template<> struct hash<DownloadId> {
-  std::size_t operator()(const DownloadId& id) const {
+template<> struct hash<content::DownloadId> {
+  std::size_t operator()(const content::DownloadId& id) const {
     return id.hash();
   }
 };
 #elif defined(COMPILER_MSVC)
-inline size_t hash_value(const DownloadId& id) {
+inline size_t hash_value(const content::DownloadId& id) {
   return id.hash();
 }
 #endif  // COMPILER
 }
-#endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ID_H_
+#endif  // CONTENT_PUBLIC_BROWSER_DOWNLOAD_ID_H_
diff --git a/content/public/browser/download_item.h b/content/public/browser/download_item.h
index 453d37f..84eeac4 100644
--- a/content/public/browser/download_item.h
+++ b/content/public/browser/download_item.h
@@ -26,7 +26,6 @@
 #include "content/browser/download/interrupt_reasons.h"
 #include "content/public/browser/download_danger_type.h"
 
-class DownloadId;
 class DownloadFileManager;
 class FilePath;
 class GURL;
@@ -41,6 +40,7 @@ class TimeDelta;
 namespace content {
 
 class BrowserContext;
+class DownloadId;
 class DownloadManager;
 class WebContents;
 
diff --git a/content/public/browser/download_manager.h b/content/public/browser/download_manager.h
index 20c584f..32aee86 100644
--- a/content/public/browser/download_manager.h
+++ b/content/public/browser/download_manager.h
@@ -36,14 +36,13 @@
 #include "base/gtest_prod_util.h"
 #include "base/message_loop_helpers.h"
 #include "base/time.h"
-#include "content/browser/download/download_id.h"
 #include "content/browser/download/interrupt_reasons.h"
+#include "content/public/browser/download_id.h"
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/base/net_errors.h"
 
 class DownloadFileManager;
-class DownloadIdFactory;
 class DownloadManagerTest;
 class DownloadRequestHandle;
 class DownloadStatusUpdater;
@@ -66,7 +65,6 @@ class CONTENT_EXPORT DownloadManager
 
   static DownloadManager* Create(
       DownloadManagerDelegate* delegate,
-      DownloadIdFactory* id_factory,
       DownloadStatusUpdater* status_updater);
 
   // Shutdown the download manager. Must be called before destruction.
diff --git a/content/public/browser/download_manager_delegate.h b/content/public/browser/download_manager_delegate.h
index 722aac7..4776ef0 100644
--- a/content/public/browser/download_manager_delegate.h
+++ b/content/public/browser/download_manager_delegate.h
@@ -14,6 +14,7 @@
 
 namespace content {
 
+class DownloadId;
 class DownloadItem;
 class WebContents;
 
@@ -28,6 +29,9 @@ class DownloadManagerDelegate {
   // Lets the delegate know that the download manager is shutting down.
   virtual void Shutdown() = 0;
 
+  // Returns a new DownloadId.
+  virtual DownloadId GetNextId() = 0;
+
   // Notifies the delegate that a download is starting. The delegate can return
   // false to delay the start of the download, in which case it should call
   // DownloadManager::RestartDownload when it's ready.
diff --git a/content/shell/shell_browser_context.cc b/content/shell/shell_browser_context.cc
index 2590ee8..f6dff1e 100644
--- a/content/shell/shell_browser_context.cc
+++ b/content/shell/shell_browser_context.cc
@@ -12,7 +12,6 @@
 #include "base/threading/thread.h"
 #include "content/browser/appcache/chrome_appcache_service.h"
 #include "content/browser/chrome_blob_storage_context.h"
-#include "content/browser/download/download_id_factory.h"
 #include "content/browser/download/download_manager_impl.h"
 #include "content/browser/download/download_status_updater.h"
 #include "content/browser/file_system/browser_file_system_helper.h"
@@ -94,8 +93,7 @@ class ShellSpeechInputPreferences : public SpeechInputPreferences {
 
 ShellBrowserContext::ShellBrowserContext(
     ShellBrowserMainParts* shell_main_parts)
-    : download_id_factory_(new DownloadIdFactory(this)),
-      shell_main_parts_(shell_main_parts) {
+    : shell_main_parts_(shell_main_parts) {
 }
 
 ShellBrowserContext::~ShellBrowserContext() {
@@ -144,7 +142,6 @@ DownloadManager* ShellBrowserContext::GetDownloadManager()  {
 
     download_manager_delegate_ = new ShellDownloadManagerDelegate();
     download_manager_ = new DownloadManagerImpl(download_manager_delegate_,
-                                                download_id_factory_,
                                                 download_status_updater_.get());
     download_manager_delegate_->SetDownloadManager(download_manager_.get());
     download_manager_->Init(this);
@@ -177,8 +174,7 @@ const ResourceContext& ShellBrowserContext::GetResourceContext()  {
   if (!resource_context_.get()) {
     resource_context_.reset(new ShellResourceContext(
         static_cast<ShellURLRequestContextGetter*>(GetRequestContext()),
-        GetBlobStorageContext(),
-        download_id_factory_));
+        GetBlobStorageContext()));
   }
   return *resource_context_.get();
 }
diff --git a/content/shell/shell_browser_context.h b/content/shell/shell_browser_context.h
index 5bf24b8..b1b8a7b 100644
--- a/content/shell/shell_browser_context.h
+++ b/content/shell/shell_browser_context.h
@@ -12,7 +12,6 @@
 #include "base/memory/scoped_ptr.h"
 #include "content/public/browser/browser_context.h"
 
-class DownloadIdFactory;
 class DownloadManager;
 class DownloadStatusUpdater;
 class HostZoomMap;
@@ -60,7 +59,6 @@ class ShellBrowserContext : public BrowserContext {
   scoped_ptr<SSLHostState> ssl_host_state_;
   scoped_ptr<DownloadStatusUpdater> download_status_updater_;
   scoped_refptr<ShellDownloadManagerDelegate> download_manager_delegate_;
-  scoped_refptr<DownloadIdFactory> download_id_factory_;
   scoped_refptr<DownloadManager> download_manager_;
   scoped_refptr<net::URLRequestContextGetter> url_request_getter_;
   scoped_refptr<HostZoomMap> host_zoom_map_;
diff --git a/content/shell/shell_download_manager_delegate.cc b/content/shell/shell_download_manager_delegate.cc
index 67ff59a..7856a66 100644
--- a/content/shell/shell_download_manager_delegate.cc
+++ b/content/shell/shell_download_manager_delegate.cc
@@ -39,6 +39,11 @@ void ShellDownloadManagerDelegate::SetDownloadManager(
 void ShellDownloadManagerDelegate::Shutdown() {
 }
 
+DownloadId ShellDownloadManagerDelegate::GetNextId() {
+  static int next_id;
+  return DownloadId(this, ++next_id);
+}
+
 bool ShellDownloadManagerDelegate::ShouldStartDownload(int32 download_id) {
   DownloadItem* download =
       download_manager_->GetActiveDownloadItem(download_id);
diff --git a/content/shell/shell_download_manager_delegate.h b/content/shell/shell_download_manager_delegate.h
index d46ac43..9cb5e97 100644
--- a/content/shell/shell_download_manager_delegate.h
+++ b/content/shell/shell_download_manager_delegate.h
@@ -25,6 +25,7 @@ class ShellDownloadManagerDelegate
   void SetDownloadManager(DownloadManager* manager);
 
   virtual void Shutdown() OVERRIDE;
+  virtual DownloadId GetNextId() OVERRIDE;
   virtual bool ShouldStartDownload(int32 download_id) OVERRIDE;
   virtual void ChooseDownloadPath(WebContents* web_contents,
                                   const FilePath& suggested_path,
diff --git a/content/shell/shell_resource_context.cc b/content/shell/shell_resource_context.cc
index 21a696f..fa725cf 100644
--- a/content/shell/shell_resource_context.cc
+++ b/content/shell/shell_resource_context.cc
@@ -5,18 +5,15 @@
 #include "content/shell/shell_resource_context.h"
 
 #include "content/browser/chrome_blob_storage_context.h"
-#include "content/browser/download/download_id_factory.h"
 #include "content/shell/shell_url_request_context_getter.h"
 
 namespace content {
 
 ShellResourceContext::ShellResourceContext(
     ShellURLRequestContextGetter* getter,
-    ChromeBlobStorageContext* blob_storage_context,
-    DownloadIdFactory* download_id_factory)
+    ChromeBlobStorageContext* blob_storage_context)
     : getter_(getter),
-      blob_storage_context_(blob_storage_context),
-      download_id_factory_(download_id_factory) {
+      blob_storage_context_(blob_storage_context) {
 }
 
 ShellResourceContext::~ShellResourceContext() {
@@ -30,7 +27,6 @@ void ShellResourceContext::InitializeInternal() {
   set_request_context(getter_->GetURLRequestContext());
   set_host_resolver(getter_->host_resolver());
   set_blob_storage_context(blob_storage_context_);
-  set_download_id_factory(download_id_factory_);
 }
 
 }  // namespace content
diff --git a/content/shell/shell_resource_context.h b/content/shell/shell_resource_context.h
index 710778e..f01a120 100644
--- a/content/shell/shell_resource_context.h
+++ b/content/shell/shell_resource_context.h
@@ -11,7 +11,6 @@
 #include "content/browser/resource_context.h"
 
 class ChromeBlobStorageContext;
-class DownloadIdFactory;
 
 namespace content {
 
@@ -21,8 +20,7 @@ class ShellResourceContext : public content::ResourceContext {
  public:
   ShellResourceContext(
       ShellURLRequestContextGetter* getter,
-      ChromeBlobStorageContext* blob_storage_context,
-      DownloadIdFactory* download_id_factory);
+      ChromeBlobStorageContext* blob_storage_context);
   virtual ~ShellResourceContext();
 
  private:
@@ -32,7 +30,6 @@ class ShellResourceContext : public content::ResourceContext {
 
   scoped_refptr<ShellURLRequestContextGetter> getter_;
   scoped_refptr<ChromeBlobStorageContext> blob_storage_context_;
-  scoped_refptr<DownloadIdFactory> download_id_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ShellResourceContext);
 };