Remove DownloadManager* dependency on DownloadStatusUpdater

by making DownloadStatusUpdater an observer of DownloadManager.

BUG=107264


Review URL: http://codereview.chromium.org/9005027

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@120487 0039d316-1c4b-4281-b951-d872f2087c98

29 files changed, 600 insertions, 160 deletions

diff --git a/chrome/browser/automation/automation_provider_observers.cc b/chrome/browser/automation/automation_provider_observers.cc
index ef8664b..fd8f69a 100644
--- a/chrome/browser/automation/automation_provider_observers.cc
+++ b/chrome/browser/automation/automation_provider_observers.cc
@@ -1592,7 +1592,10 @@ AutomationProviderDownloadModelChangedObserver(
 AutomationProviderDownloadModelChangedObserver::
     ~AutomationProviderDownloadModelChangedObserver() {}
 
-void AutomationProviderDownloadModelChangedObserver::ModelChanged() {
+void AutomationProviderDownloadModelChangedObserver::ModelChanged(
+    DownloadManager* manager) {
+  DCHECK_EQ(manager, download_manager_);
+
   download_manager_->RemoveObserver(this);
 
   if (provider_)
@@ -1625,7 +1628,8 @@ AllDownloadsCompleteObserver::AllDownloadsCompleteObserver(
 
 AllDownloadsCompleteObserver::~AllDownloadsCompleteObserver() {}
 
-void AllDownloadsCompleteObserver::ModelChanged() {
+void AllDownloadsCompleteObserver::ModelChanged(DownloadManager* manager) {
+  DCHECK_EQ(manager, download_manager_);
   // The set of downloads in the download manager has changed.  If there are
   // any new downloads that are still in progress, add them to the pending list.
   std::vector<DownloadItem*> downloads;
@@ -1641,8 +1645,7 @@ void AllDownloadsCompleteObserver::ModelChanged() {
   ReplyIfNecessary();
 }
 
-void AllDownloadsCompleteObserver::OnDownloadUpdated(
-    content::DownloadItem* download) {
+void AllDownloadsCompleteObserver::OnDownloadUpdated(DownloadItem* download) {
   // If the current download's status has changed to a final state (not state
   // "in progress"), remove it from the pending list.
   if (download->GetState() != DownloadItem::IN_PROGRESS) {
diff --git a/chrome/browser/automation/automation_provider_observers.h b/chrome/browser/automation/automation_provider_observers.h
index 3a7472d..a5e681b 100644
--- a/chrome/browser/automation/automation_provider_observers.h
+++ b/chrome/browser/automation/automation_provider_observers.h
@@ -1117,7 +1117,7 @@ class AutomationProviderDownloadModelChangedObserver
       content::DownloadManager* download_manager);
   virtual ~AutomationProviderDownloadModelChangedObserver();
 
-  virtual void ModelChanged();
+  virtual void ModelChanged(content::DownloadManager* manager) OVERRIDE;
 
  private:
   base::WeakPtr<AutomationProvider> provider_;
@@ -1139,12 +1139,12 @@ class AllDownloadsCompleteObserver
       ListValue* pre_download_ids);
   virtual ~AllDownloadsCompleteObserver();
 
-  // DownloadManager::Observer.
-  virtual void ModelChanged();
+  // content::DownloadManager::Observer.
+  virtual void ModelChanged(content::DownloadManager* manager) OVERRIDE;
 
-  // DownloadItem::Observer.
-  virtual void OnDownloadUpdated(content::DownloadItem* download);
-  virtual void OnDownloadOpened(content::DownloadItem* download) {}
+  // content::DownloadItem::Observer.
+  virtual void OnDownloadUpdated(content::DownloadItem* download) OVERRIDE;
+  virtual void OnDownloadOpened(content::DownloadItem* download) OVERRIDE {}
 
  private:
   void ReplyIfNecessary();
diff --git a/chrome/browser/browser_process_impl.cc b/chrome/browser/browser_process_impl.cc
index ba2bd92..f434f60 100644
--- a/chrome/browser/browser_process_impl.cc
+++ b/chrome/browser/browser_process_impl.cc
@@ -25,6 +25,7 @@
 #include "chrome/browser/component_updater/component_updater_service.h"
 #include "chrome/browser/debugger/remote_debugging_server.h"
 #include "chrome/browser/download/download_request_limiter.h"
+#include "chrome/browser/download/download_status_updater.h"
 #include "chrome/browser/extensions/extension_event_router_forwarder.h"
 #include "chrome/browser/extensions/extension_tab_id_map.h"
 #include "chrome/browser/extensions/network_delay_listener.h"
@@ -67,7 +68,6 @@
 #include "chrome/common/url_constants.h"
 #include "chrome/installer/util/google_update_constants.h"
 #include "content/browser/child_process_security_policy.h"
-#include "content/browser/download/download_status_updater.h"
 #include "content/browser/download/mhtml_generation_manager.h"
 #include "content/browser/gpu/gpu_process_host_ui_shim.h"
 #include "content/browser/net/browser_online_state_observer.h"
diff --git a/chrome/browser/chromeos/imageburner/burn_controller.cc b/chrome/browser/chromeos/imageburner/burn_controller.cc
index 15f85c1..f2ae353 100644
--- a/chrome/browser/chromeos/imageburner/burn_controller.cc
+++ b/chrome/browser/chromeos/imageburner/burn_controller.cc
@@ -19,8 +19,6 @@
 #include "grit/generated_resources.h"
 #include "googleurl/src/gurl.h"
 
-using content::DownloadItem;
-
 namespace chromeos {
 namespace imageburner {
 
@@ -46,7 +44,7 @@ class BurnControllerImpl
       public disks::DiskMountManager::Observer,
       public BurnLibrary::Observer,
       public NetworkLibrary::NetworkManagerObserver,
-      public DownloadItem::Observer,
+      public content::DownloadItem::Observer,
       public content::DownloadManager::Observer,
       public Downloader::Listener,
       public StateMachine::Observer,
@@ -143,8 +141,8 @@ class BurnControllerImpl
       ProcessError(IDS_IMAGEBURN_NETWORK_ERROR);
   }
 
-  // DownloadItem::Observer interface.
-  virtual void OnDownloadUpdated(DownloadItem* download) OVERRIDE {
+  // content::DownloadItem::Observer interface.
+  virtual void OnDownloadUpdated(content::DownloadItem* download) OVERRIDE {
     if (download->IsCancelled()) {
       DownloadCompleted(false);
       DCHECK(!active_download_item_);
@@ -162,22 +160,22 @@ class BurnControllerImpl
     }
   }
 
-  virtual void OnDownloadOpened(DownloadItem* download) OVERRIDE {
-    if (download->GetSafetyState() == DownloadItem::DANGEROUS)
+  virtual void OnDownloadOpened(content::DownloadItem* download) OVERRIDE {
+    if (download->GetSafetyState() == content::DownloadItem::DANGEROUS)
       download->DangerousDownloadValidated();
   }
 
-  // DownloadManager::Observer interface.
-  virtual void ModelChanged() OVERRIDE {
+  // content::DownloadManager::Observer interface.
+  virtual void ModelChanged(content::DownloadManager* manager) OVERRIDE {
+    DCHECK_EQ(download_manager_, manager);
     // Find our item and observe it.
-    std::vector<DownloadItem*> downloads;
+    std::vector<content::DownloadItem*> downloads;
     download_manager_->GetTemporaryDownloads(
         burn_manager_->GetImageDir(), &downloads);
     if (active_download_item_)
       return;
-    for (std::vector<DownloadItem*>::const_iterator it = downloads.begin();
-         it != downloads.end();
-         ++it) {
+    for (std::vector<content::DownloadItem*>::const_iterator it =
+             downloads.begin(); it != downloads.end(); ++it) {
       if ((*it)->GetOriginalUrl() == image_download_url_) {
         (*it)->AddObserver(this);
         active_download_item_ = *it;
@@ -379,7 +377,8 @@ class BurnControllerImpl
         active_download_item_->RemoveObserver(this);
         if (active_download_item_->IsPartialDownload())
           active_download_item_->Cancel(true);
-        active_download_item_->Delete(DownloadItem::DELETE_DUE_TO_USER_DISCARD);
+        active_download_item_->Delete(
+            content::DownloadItem::DELETE_DUE_TO_USER_DISCARD);
         active_download_item_ = NULL;
         CleanupDownloadObjects();
       }
@@ -440,7 +439,7 @@ class BurnControllerImpl
   std::string image_file_name_;
   content::WebContents* web_contents_;
   content::DownloadManager* download_manager_;
-  DownloadItem*  active_download_item_;
+  content::DownloadItem*  active_download_item_;
   BurnManager* burn_manager_;
   StateMachine* state_machine_;
   bool observing_burn_lib_;
diff --git a/chrome/browser/chromeos/imageburner/burn_manager.cc b/chrome/browser/chromeos/imageburner/burn_manager.cc
index 3b8db3f..502b588 100644
--- a/chrome/browser/chromeos/imageburner/burn_manager.cc
+++ b/chrome/browser/chromeos/imageburner/burn_manager.cc
@@ -294,7 +294,9 @@ void BurnManager::OnConfigFileDownloaded() {
                             weak_ptr_factory_.GetWeakPtr())));
 }
 
-void BurnManager::ModelChanged() {
+void BurnManager::ModelChanged(DownloadManager* manager) {
+  DCHECK_EQ(download_manager_, manager);
+
   std::vector<DownloadItem*> downloads;
   download_manager_->GetTemporaryDownloads(GetImageDir(), &downloads);
   if (download_item_observer_added_)
diff --git a/chrome/browser/chromeos/imageburner/burn_manager.h b/chrome/browser/chromeos/imageburner/burn_manager.h
index 50e6d10..a819a6a 100644
--- a/chrome/browser/chromeos/imageburner/burn_manager.h
+++ b/chrome/browser/chromeos/imageburner/burn_manager.h
@@ -32,7 +32,7 @@ class Downloader {
   class Listener : public base::SupportsWeakPtr<Listener> {
    public:
     // After download starts download status updates can be followed through
-    // DownloadItem::Observer interface.
+    // content::DownloadItem::Observer interface.
     virtual void OnBurnDownloadStarted(bool success) = 0;
   };
 
@@ -225,7 +225,7 @@ class BurnManager
   virtual void OnDownloadOpened(content::DownloadItem* download) OVERRIDE {}
 
   // content::DownloadManager::Observer interface.
-  virtual void ModelChanged() OVERRIDE;
+  virtual void ModelChanged(content::DownloadManager* manager) OVERRIDE;
 
   // Downloader::Listener interface.
   virtual void OnBurnDownloadStarted(bool success) OVERRIDE;
@@ -306,5 +306,7 @@ class BurnManager
 };
 
 }  // namespace imageburner
+
 }  // namespace chromeos
+
 #endif  // CHROME_BROWSER_CHROMEOS_IMAGEBURNER_BURN_MANAGER_H_
diff --git a/chrome/browser/download/chrome_download_manager_delegate.cc b/chrome/browser/download/chrome_download_manager_delegate.cc
index 9793901..04746e5 100644
--- a/chrome/browser/download/chrome_download_manager_delegate.cc
+++ b/chrome/browser/download/chrome_download_manager_delegate.cc
@@ -18,6 +18,7 @@
 #include "chrome/browser/download/download_file_picker.h"
 #include "chrome/browser/download/download_history.h"
 #include "chrome/browser/download/download_prefs.h"
+#include "chrome/browser/download/download_status_updater.h"
 #include "chrome/browser/download/download_util.h"
 #include "chrome/browser/download/save_package_file_picker.h"
 #include "chrome/browser/extensions/crx_installer.h"
@@ -32,7 +33,6 @@
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/extensions/user_script.h"
 #include "chrome/common/pref_names.h"
-#include "content/browser/download/download_status_updater.h"
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/download_manager.h"
 #include "content/public/browser/notification_source.h"
diff --git a/chrome/browser/download/download_browsertest.cc b/chrome/browser/download/download_browsertest.cc
index 4759591..1cf1b05 100644
--- a/chrome/browser/download/download_browsertest.cc
+++ b/chrome/browser/download/download_browsertest.cc
@@ -254,7 +254,7 @@ static DownloadManager* DownloadManagerForBrowser(Browser* browser) {
 
 // While an object of this class exists, it will mock out download
 // opening for all downloads created on the specified download manager.
-class MockDownloadOpeningObserver : public content::DownloadManager::Observer {
+class MockDownloadOpeningObserver : public DownloadManager::Observer {
  public:
   explicit MockDownloadOpeningObserver(DownloadManager* manager)
       : download_manager_(manager) {
@@ -266,7 +266,8 @@ class MockDownloadOpeningObserver : public content::DownloadManager::Observer {
   }
 
   // DownloadManager::Observer
-  virtual void ModelChanged() {
+  virtual void ModelChanged(DownloadManager* manager) OVERRIDE {
+    DCHECK_EQ(manager, download_manager_);
     std::vector<DownloadItem*> downloads;
     download_manager_->SearchDownloads(string16(), &downloads);
 
diff --git a/chrome/browser/download/download_extension_api.cc b/chrome/browser/download/download_extension_api.cc
index 803404d..4d3fd55 100644
--- a/chrome/browser/download/download_extension_api.cc
+++ b/chrome/browser/download/download_extension_api.cc
@@ -884,10 +884,9 @@ ExtensionDownloadsEventRouter::~ExtensionDownloadsEventRouter() {
     manager_->RemoveObserver(this);
 }
 
-void ExtensionDownloadsEventRouter::ModelChanged() {
+void ExtensionDownloadsEventRouter::ModelChanged(DownloadManager* manager) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (manager_ == NULL)
-    return;
+  DCHECK(manager_ == manager);
   DownloadManager::DownloadVector current_vec;
   manager_->SearchDownloads(string16(), &current_vec);
   DownloadIdSet current_set;
@@ -929,7 +928,8 @@ void ExtensionDownloadsEventRouter::ModelChanged() {
   downloads_.swap(current_set);
 }
 
-void ExtensionDownloadsEventRouter::ManagerGoingDown() {
+void ExtensionDownloadsEventRouter::ManagerGoingDown(
+    DownloadManager* manager) {
   manager_->RemoveObserver(this);
   manager_ = NULL;
 }
diff --git a/chrome/browser/download/download_extension_api.h b/chrome/browser/download/download_extension_api.h
index 348425e..0fc7be2 100644
--- a/chrome/browser/download/download_extension_api.h
+++ b/chrome/browser/download/download_extension_api.h
@@ -307,8 +307,8 @@ class ExtensionDownloadsEventRouter
   explicit ExtensionDownloadsEventRouter(Profile* profile);
   virtual ~ExtensionDownloadsEventRouter();
 
-  virtual void ModelChanged() OVERRIDE;
-  virtual void ManagerGoingDown() OVERRIDE;
+  virtual void ModelChanged(content::DownloadManager* manager) OVERRIDE;
+  virtual void ManagerGoingDown(content::DownloadManager* manager) OVERRIDE;
 
  private:
   void Init(content::DownloadManager* manager);
diff --git a/chrome/browser/download/download_file_picker.cc b/chrome/browser/download/download_file_picker.cc
index 2451ce6..4db364b 100644
--- a/chrome/browser/download/download_file_picker.cc
+++ b/chrome/browser/download/download_file_picker.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -42,10 +42,11 @@ DownloadFilePicker::DownloadFilePicker(
 DownloadFilePicker::~DownloadFilePicker() {
 }
 
-void DownloadFilePicker::ModelChanged() {
+void DownloadFilePicker::ModelChanged(DownloadManager* manager) {
 }
 
-void DownloadFilePicker::ManagerGoingDown() {
+void DownloadFilePicker::ManagerGoingDown(DownloadManager* manager) {
+  DCHECK_EQ(download_manager_, manager);
   download_manager_ = NULL;
 }
 
diff --git a/chrome/browser/download/download_file_picker.h b/chrome/browser/download/download_file_picker.h
index f7d7340..fdd16ad 100644
--- a/chrome/browser/download/download_file_picker.h
+++ b/chrome/browser/download/download_file_picker.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -27,8 +27,8 @@ class DownloadFilePicker : public content::DownloadManager::Observer,
 
  private:
   // content::DownloadManager::Observer implementation.
-  virtual void ModelChanged() OVERRIDE;
-  virtual void ManagerGoingDown() OVERRIDE;
+  virtual void ModelChanged(content::DownloadManager* manager) OVERRIDE;
+  virtual void ManagerGoingDown(content::DownloadManager* manager) OVERRIDE;
 
   // SelectFileDialog::Listener implementation.
   virtual void FileSelected(const FilePath& path,
diff --git a/chrome/browser/download/download_query_unittest.cc b/chrome/browser/download/download_query_unittest.cc
index 2a5e465..2fb5e7b 100644
--- a/chrome/browser/download/download_query_unittest.cc
+++ b/chrome/browser/download/download_query_unittest.cc
@@ -49,11 +49,11 @@ class DownloadQueryTest : public testing::Test {
 
   void CreateMocks(int count) {
     for (int i = 0; i < count; ++i) {
-      mocks_.push_back(new MockDownloadItem());
+      mocks_.push_back(new content::MockDownloadItem());
     }
   }
 
-  MockDownloadItem& mock(int index) { return *mocks_[index]; }
+  content::MockDownloadItem& mock(int index) { return *mocks_[index]; }
 
   DownloadQuery* query() { return &query_; }
 
@@ -67,7 +67,7 @@ class DownloadQueryTest : public testing::Test {
   DownloadVector* results() { return &results_; }
 
  private:
-  std::vector<MockDownloadItem*> mocks_;
+  std::vector<content::MockDownloadItem*> mocks_;
   DownloadQuery query_;
   DownloadVector results_;
 
diff --git a/chrome/browser/download/download_service.cc b/chrome/browser/download/download_service.cc
index 65e1124..b58e0c2 100644
--- a/chrome/browser/download/download_service.cc
+++ b/chrome/browser/download/download_service.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -8,6 +8,7 @@
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/download/chrome_download_manager_delegate.h"
 #include "chrome/browser/download/download_service_factory.h"
+#include "chrome/browser/download/download_status_updater.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "content/public/browser/download_manager.h"
@@ -36,10 +37,14 @@ DownloadManager* DownloadService::GetDownloadManager() {
     // SetDownloadManagerDelegateForTesting.
     if (!manager_delegate_.get())
       manager_delegate_ = new ChromeDownloadManagerDelegate(profile_);
-    manager_ = DownloadManager::Create(
-        manager_delegate_.get(), g_browser_process->download_status_updater());
+    manager_ = DownloadManager::Create(manager_delegate_.get());
     manager_->Init(profile_);
     manager_delegate_->SetDownloadManager(manager_);
+
+    // Include this download manager in the set monitored by the
+    // global status updater.
+    g_browser_process->download_status_updater()->AddManager(manager_);
+
     download_manager_created_ = true;
     for (std::vector<OnManagerCreatedCallback>::iterator cb
          = on_manager_created_callbacks_.begin();
diff --git a/chrome/browser/download/download_status_updater.cc b/chrome/browser/download/download_status_updater.cc
new file mode 100644
index 0000000..d06df41
--- /dev/null
+++ b/chrome/browser/download/download_status_updater.cc
@@ -0,0 +1,101 @@
+// 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/browser/download/download_status_updater.h"
+
+#include <vector>
+
+#include "base/logging.h"
+#include "base/stl_util.h"
+
+DownloadStatusUpdater::DownloadStatusUpdater() {
+}
+
+DownloadStatusUpdater::~DownloadStatusUpdater() {
+  for (std::set<content::DownloadManager*>::iterator it = managers_.begin();
+       it != managers_.end(); ++it)
+    (*it)->RemoveObserver(this);
+
+  for (std::set<content::DownloadItem*>::iterator it = items_.begin();
+       it != items_.end(); ++it)
+    (*it)->RemoveObserver(this);
+}
+
+bool DownloadStatusUpdater::GetProgress(float* progress,
+                                        int* download_count) const {
+  *progress = 0;
+  *download_count = items_.size();
+
+  int64 received_bytes = 0;
+  int64 total_bytes = 0;
+  for (std::set<content::DownloadItem*>::const_iterator it = items_.begin();
+       it != items_.end(); ++it) {
+    if ((*it)->GetTotalBytes() <= 0)
+      // We don't know how much more is coming down this pipe.
+      return false;
+    received_bytes += (*it)->GetReceivedBytes();
+    total_bytes += (*it)->GetTotalBytes();
+  }
+
+  if (total_bytes > 0)
+    *progress = static_cast<float>(received_bytes) / total_bytes;
+  return true;
+}
+
+void DownloadStatusUpdater::AddManager(content::DownloadManager* manager) {
+  DCHECK(!ContainsKey(managers_, manager));
+  managers_.insert(manager);
+  manager->AddObserver(this);
+}
+
+// Methods inherited from content::DownloadManager::Observer.
+void DownloadStatusUpdater::ModelChanged(content::DownloadManager* manager) {
+  std::vector<content::DownloadItem*> downloads;
+  manager->SearchDownloads(string16(), &downloads);
+
+  for (std::vector<content::DownloadItem*>::iterator it = downloads.begin();
+       it != downloads.end(); ++it) {
+    UpdateItem(*it);
+  }
+}
+
+void DownloadStatusUpdater::ManagerGoingDown(
+    content::DownloadManager* manager) {
+  DCHECK(ContainsKey(managers_, manager));
+  managers_.erase(manager);
+  manager->RemoveObserver(this);
+  // Item removal will be handled in response to DownloadItem REMOVING
+  // notification (in the !IN_PROGRESS conditional branch in UpdateItem).
+}
+
+void DownloadStatusUpdater::SelectFileDialogDisplayed(
+    content::DownloadManager* manager, int32 id) {
+}
+
+// Methods inherited from content::DownloadItem::Observer.
+void DownloadStatusUpdater::OnDownloadUpdated(
+    content::DownloadItem* download) {
+  UpdateItem(download);
+}
+
+void DownloadStatusUpdater::OnDownloadOpened(content::DownloadItem* download) {
+}
+
+// React to a transition that a download associated with one of our
+// download managers has made.  Our goal is to have only IN_PROGRESS
+// items on our set list, as they're the only ones that have relevance
+// to GetProgress() return values.
+void DownloadStatusUpdater::UpdateItem(content::DownloadItem* download) {
+  if (download->GetState() == content::DownloadItem::IN_PROGRESS) {
+    if (!ContainsKey(items_, download)) {
+      items_.insert(download);
+      download->AddObserver(this);
+    }
+  } else {
+    if (ContainsKey(items_, download)) {
+      items_.erase(download);
+      download->RemoveObserver(this);
+    }
+  }
+}
diff --git a/chrome/browser/download/download_status_updater.h b/chrome/browser/download/download_status_updater.h
new file mode 100644
index 0000000..d220163
--- /dev/null
+++ b/chrome/browser/download/download_status_updater.h
@@ -0,0 +1,55 @@
+// 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.
+
+#ifndef CHROME_BROWSER_DOWNLOAD_DOWNLOAD_STATUS_UPDATER_H_
+#define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_STATUS_UPDATER_H_
+
+#include <set>
+
+#include "base/basictypes.h"
+#include "content/public/browser/download_item.h"
+#include "content/public/browser/download_manager.h"
+
+// Keeps track of download progress for the entire browser.
+class DownloadStatusUpdater
+    : public content::DownloadManager::Observer,
+      public content::DownloadItem::Observer {
+ public:
+  DownloadStatusUpdater();
+  virtual ~DownloadStatusUpdater();
+
+  // Fills in |*download_count| with the number of currently active downloads.
+  // If we know the final size of all downloads, this routine returns true
+  // with |*progress| set to the percentage complete of all in-progress
+  // downloads.  Otherwise, it returns false.
+  bool GetProgress(float* progress, int* download_count) const;
+
+  // Add the specified DownloadManager to the list of managers for which
+  // this object reports status.
+  // The manager must not have previously been added to this updater.
+  // The updater will automatically disassociate itself from the
+  // manager when the manager is shutdown.
+  void AddManager(content::DownloadManager* manager);
+
+  // Methods inherited from content::DownloadManager::Observer.
+  virtual void ModelChanged(content::DownloadManager* manager) OVERRIDE;
+  virtual void ManagerGoingDown(content::DownloadManager* manager) OVERRIDE;
+  virtual void SelectFileDialogDisplayed(
+      content::DownloadManager* manager, int32 id) OVERRIDE;
+
+  // Methods inherited from content::DownloadItem::Observer.
+  virtual void OnDownloadUpdated(content::DownloadItem* download) OVERRIDE;
+  virtual void OnDownloadOpened(content::DownloadItem* download) OVERRIDE;
+
+ private:
+  // Update the internal state tracking an item.
+  void UpdateItem(content::DownloadItem* download);
+
+  std::set<content::DownloadManager*> managers_;
+  std::set<content::DownloadItem*> items_;
+
+  DISALLOW_COPY_AND_ASSIGN(DownloadStatusUpdater);
+};
+
+#endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_STATUS_UPDATER_H_
diff --git a/chrome/browser/download/download_status_updater_unittest.cc b/chrome/browser/download/download_status_updater_unittest.cc
new file mode 100644
index 0000000..31e6bac
--- /dev/null
+++ b/chrome/browser/download/download_status_updater_unittest.cc
@@ -0,0 +1,283 @@
+// 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 "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "base/message_loop.h"
+#include "base/stl_util.h"
+#include "chrome/browser/download/download_status_updater.h"
+#include "content/browser/download/download_request_handle.h"
+#include "content/browser/download/download_types.h"
+#include "content/test/mock_download_item.h"
+#include "content/test/mock_download_manager.h"
+#include "content/test/test_browser_thread.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+
+using ::testing::AtLeast;
+using ::testing::Mock;
+using ::testing::Return;
+using ::testing::SetArgPointee;
+using ::testing::StrictMock;
+using ::testing::_;
+
+class DownloadStatusUpdaterTest : public testing::Test {
+ public:
+  DownloadStatusUpdaterTest()
+      : updater_(new DownloadStatusUpdater()),
+        ui_thread_(content::BrowserThread::UI, &loop_) {}
+
+  virtual ~DownloadStatusUpdaterTest() {
+    for (size_t mgr_idx = 0; mgr_idx < managers_.size(); ++mgr_idx) {
+      EXPECT_CALL(*Manager(mgr_idx), RemoveObserver(updater_));
+      for (size_t item_idx = 0; item_idx < manager_items_[mgr_idx].size();
+           ++item_idx) {
+        if (Item(mgr_idx, item_idx)->GetState() ==
+            content::DownloadItem::IN_PROGRESS)
+          EXPECT_CALL(*Item(mgr_idx, item_idx), RemoveObserver(updater_));
+      }
+    }
+
+    delete updater_;
+    updater_ = NULL;
+    VerifyAndClearExpectations();
+
+    managers_.clear();
+    for (std::vector<Items>::iterator it = manager_items_.begin();
+         it != manager_items_.end(); ++it)
+      STLDeleteContainerPointers(it->begin(), it->end());
+
+    loop_.RunAllPending();  // Allow DownloadManager destruction.
+  }
+
+ protected:
+  // Attach some number of DownloadManagers to the updater.
+  void SetupManagers(int manager_count) {
+    DCHECK_EQ(0U, managers_.size());
+    for (int i = 0; i < manager_count; ++i) {
+      content::MockDownloadManager* mgr =
+          new StrictMock<content::MockDownloadManager>;
+      managers_.push_back(make_scoped_refptr(mgr));
+    }
+  }
+
+  // Hook the specified manager into the updater.
+  void LinkManager(int i) {
+    content::MockDownloadManager* mgr = managers_[i].get();
+    EXPECT_CALL(*mgr, AddObserver(updater_));
+    updater_->AddManager(mgr);
+    updater_->ModelChanged(mgr);
+  }
+
+  // Add some number of Download items to a particular manager.
+  void AddItems(int manager_index, int item_count, int in_progress_count) {
+    DCHECK_GT(managers_.size(), static_cast<size_t>(manager_index));
+    content::MockDownloadManager* manager = managers_[manager_index].get();
+
+    if (manager_items_.size() <= static_cast<size_t>(manager_index))
+      manager_items_.resize(manager_index+1);
+
+    std::vector<content::DownloadItem*> item_list;
+    for (int i = 0; i < item_count; ++i) {
+      content::MockDownloadItem* item =
+          new StrictMock<content::MockDownloadItem>;
+      if (i < in_progress_count) {
+        EXPECT_CALL(*item, GetState())
+            .WillRepeatedly(Return(content::DownloadItem::IN_PROGRESS));
+        EXPECT_CALL(*item, AddObserver(updater_))
+            .WillOnce(Return());
+      } else {
+        EXPECT_CALL(*item, GetState())
+            .WillRepeatedly(Return(content::DownloadItem::COMPLETE));
+      }
+      manager_items_[manager_index].push_back(item);
+    }
+    EXPECT_CALL(*manager, SearchDownloads(string16(), _))
+        .WillOnce(SetArgPointee<1>(manager_items_[manager_index]));
+  }
+
+  // Return the specified manager.
+  content::MockDownloadManager* Manager(int manager_index) {
+    DCHECK_GT(managers_.size(), static_cast<size_t>(manager_index));
+    return managers_[manager_index].get();
+  }
+
+  // Return the specified item.
+  content::MockDownloadItem* Item(int manager_index, int item_index) {
+    DCHECK_GT(manager_items_.size(), static_cast<size_t>(manager_index));
+    DCHECK_GT(manager_items_[manager_index].size(),
+              static_cast<size_t>(item_index));
+    // All DownloadItems in manager_items_ are MockDownloadItems.
+    return static_cast<content::MockDownloadItem*>(
+        manager_items_[manager_index][item_index]);
+  }
+
+  // Set return values relevant to |DownloadStatusUpdater::GetProgress()|
+  // for the specified item
+  void SetItemValues(int manager_index, int item_index,
+                     int received_bytes, int total_bytes) {
+    EXPECT_CALL(*Item(manager_index, item_index), GetReceivedBytes())
+        .WillRepeatedly(Return(received_bytes));
+    EXPECT_CALL(*Item(manager_index, item_index), GetTotalBytes())
+        .WillRepeatedly(Return(total_bytes));
+  }
+
+  // Transition specified item to completed.
+  void CompleteItem(int manager_index, int item_index) {
+    content::MockDownloadItem* item(Item(manager_index, item_index));
+    EXPECT_CALL(*item, GetState())
+        .WillRepeatedly(Return(content::DownloadItem::COMPLETE));
+    EXPECT_CALL(*item, RemoveObserver(updater_))
+        .WillOnce(Return());
+    updater_->OnDownloadUpdated(item);
+  }
+
+  // Verify and clear all mocks expectations.
+  void VerifyAndClearExpectations() {
+    for (std::vector<scoped_refptr<content::MockDownloadManager> >::iterator it
+             = managers_.begin(); it != managers_.end(); ++it)
+      Mock::VerifyAndClearExpectations(it->get());
+    for (std::vector<Items>::iterator it = manager_items_.begin();
+         it != manager_items_.end(); ++it)
+      for (Items::iterator sit = it->begin(); sit != it->end(); ++sit)
+        Mock::VerifyAndClearExpectations(*sit);
+  }
+
+  std::vector<scoped_refptr<content::MockDownloadManager> > managers_;
+  // DownloadItem so that it can be assigned to the result of SearchDownloads.
+  typedef std::vector<content::DownloadItem*> Items;
+  std::vector<Items> manager_items_;
+
+  // Pointer so we can verify that destruction triggers appropriate
+  // changes.
+  DownloadStatusUpdater *updater_;
+
+  // Thread so that the DownloadManager (which is a DeleteOnUIThread
+  // object) can be deleted.
+  // TODO(rdsmith): This can be removed when the DownloadManager
+  // is no longer required to be deleted on the UI thread.
+  MessageLoop loop_;
+  content::TestBrowserThread ui_thread_;
+};
+
+// Test null updater.
+TEST_F(DownloadStatusUpdaterTest, Basic) {
+  float progress = -1;
+  int download_count = -1;
+  EXPECT_TRUE(updater_->GetProgress(&progress, &download_count));
+  EXPECT_FLOAT_EQ(0.0f, progress);
+  EXPECT_EQ(0, download_count);
+}
+
+// Test updater with null manager.
+TEST_F(DownloadStatusUpdaterTest, OneManagerNoItems) {
+  SetupManagers(1);
+  AddItems(0, 0, 0);
+  LinkManager(0);
+  VerifyAndClearExpectations();
+
+  float progress = -1;
+  int download_count = -1;
+  EXPECT_TRUE(updater_->GetProgress(&progress, &download_count));
+  EXPECT_FLOAT_EQ(0.0f, progress);
+  EXPECT_EQ(0, download_count);
+}
+
+// Test updater with non-null manager, including transition an item to
+// |content::DownloadItem::COMPLETE| and adding a new item.
+TEST_F(DownloadStatusUpdaterTest, OneManagerManyItems) {
+  SetupManagers(1);
+  AddItems(0, 3, 2);
+  LinkManager(0);
+
+  // Prime items
+  SetItemValues(0, 0, 10, 20);
+  SetItemValues(0, 1, 50, 60);
+  SetItemValues(0, 2, 90, 90);
+
+  float progress = -1;
+  int download_count = -1;
+  EXPECT_TRUE(updater_->GetProgress(&progress, &download_count));
+  EXPECT_FLOAT_EQ((10+50)/(20.0f+60), progress);
+  EXPECT_EQ(2, download_count);
+
+  // Transition one item to completed and confirm progress is updated
+  // properly.
+  CompleteItem(0, 0);
+  EXPECT_TRUE(updater_->GetProgress(&progress, &download_count));
+  EXPECT_FLOAT_EQ(50/60.0f, progress);
+  EXPECT_EQ(1, download_count);
+
+  // Add a new item to manager and confirm progress is updated properly.
+  AddItems(0, 1, 1);
+  updater_->ModelChanged(Manager(0));
+  SetItemValues(0, 3, 150, 200);
+
+  EXPECT_TRUE(updater_->GetProgress(&progress, &download_count));
+  EXPECT_FLOAT_EQ((50+150)/(60+200.0f), progress);
+  EXPECT_EQ(2, download_count);
+}
+
+// Confirm we recognize the situation where we have an unknown size.
+TEST_F(DownloadStatusUpdaterTest, UnknownSize) {
+  SetupManagers(1);
+  AddItems(0, 2, 2);
+  LinkManager(0);
+
+  // Prime items
+  SetItemValues(0, 0, 10, 20);
+  SetItemValues(0, 1, 50, -1);
+
+  float progress = -1;
+  int download_count = -1;
+  EXPECT_FALSE(updater_->GetProgress(&progress, &download_count));
+}
+
+// Test many null managers.
+TEST_F(DownloadStatusUpdaterTest, ManyManagersNoItems) {
+  SetupManagers(1);
+  AddItems(0, 0, 0);
+  LinkManager(0);
+
+  float progress = -1;
+  int download_count = -1;
+  EXPECT_TRUE(updater_->GetProgress(&progress, &download_count));
+  EXPECT_FLOAT_EQ(0.0f, progress);
+  EXPECT_EQ(0, download_count);
+}
+
+// Test many managers with all items complete.
+TEST_F(DownloadStatusUpdaterTest, ManyManagersEmptyItems) {
+  SetupManagers(2);
+  AddItems(0, 3, 0);
+  LinkManager(0);
+  AddItems(1, 3, 0);
+  LinkManager(1);
+
+  float progress = -1;
+  int download_count = -1;
+  EXPECT_TRUE(updater_->GetProgress(&progress, &download_count));
+  EXPECT_FLOAT_EQ(0.0f, progress);
+  EXPECT_EQ(0, download_count);
+}
+
+// Test many managers with some non-complete items.
+TEST_F(DownloadStatusUpdaterTest, ManyManagersMixedItems) {
+  SetupManagers(2);
+  AddItems(0, 3, 2);
+  LinkManager(0);
+  AddItems(1, 3, 1);
+  LinkManager(1);
+
+  SetItemValues(0, 0, 10, 20);
+  SetItemValues(0, 1, 50, 60);
+  SetItemValues(1, 0, 80, 90);
+
+  float progress = -1;
+  int download_count = -1;
+  EXPECT_TRUE(updater_->GetProgress(&progress, &download_count));
+  EXPECT_FLOAT_EQ((10+50+80)/(20.0f+60+90), progress);
+  EXPECT_EQ(3, download_count);
+}
diff --git a/chrome/browser/download/download_test_observer.cc b/chrome/browser/download/download_test_observer.cc
index 06b7c47..c495a9f 100644
--- a/chrome/browser/download/download_test_observer.cc
+++ b/chrome/browser/download/download_test_observer.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -82,7 +82,7 @@ bool DownloadTestObserver::IsFinished() const {
   return (finish_on_select_file_ && select_file_dialog_seen_);
 }
 
-void DownloadTestObserver::OnDownloadUpdated(content::DownloadItem* download) {
+void DownloadTestObserver::OnDownloadUpdated(DownloadItem* download) {
   // The REMOVING state indicates that the download is being destroyed.
   // Stop observing.  Do not do anything with it, as it is about to be gone.
   if (download->GetState() == DownloadItem::REMOVING) {
@@ -134,7 +134,9 @@ void DownloadTestObserver::OnDownloadUpdated(content::DownloadItem* download) {
   }
 }
 
-void DownloadTestObserver::ModelChanged() {
+void DownloadTestObserver::ModelChanged(DownloadManager* manager) {
+  DCHECK_EQ(manager, download_manager_);
+
   // Regenerate DownloadItem observers.  If there are any download items
   // in our final state, note them in |finished_downloads_|
   // (done by |OnDownloadUpdated()|).
@@ -169,7 +171,9 @@ void DownloadTestObserver::ModelChanged() {
   }
 }
 
-void DownloadTestObserver::SelectFileDialogDisplayed(int32 /* id */) {
+void DownloadTestObserver::SelectFileDialogDisplayed(
+    DownloadManager* manager, int32 /* id */) {
+  DCHECK_EQ(manager, download_manager_);
   select_file_dialog_seen_ = true;
   SignalIfFinished();
 }
@@ -206,13 +210,12 @@ void DownloadTestFlushObserver::WaitForFlush() {
   ui_test_utils::RunMessageLoop();
 }
 
-void DownloadTestFlushObserver::ModelChanged() {
+void DownloadTestFlushObserver::ModelChanged(DownloadManager* manager) {
   // Model has changed, so there may be more DownloadItems to observe.
   CheckDownloadsInProgress(true);
 }
 
-void DownloadTestFlushObserver::OnDownloadUpdated(
-    content::DownloadItem* download) {
+void DownloadTestFlushObserver::OnDownloadUpdated(DownloadItem* download) {
   // The REMOVING state indicates that the download is being destroyed.
   // Stop observing.  Do not do anything with it, as it is about to be gone.
   if (download->GetState() == DownloadItem::REMOVING) {
diff --git a/chrome/browser/download/download_test_observer.h b/chrome/browser/download/download_test_observer.h
index ad32ce4..3404f42 100644
--- a/chrome/browser/download/download_test_observer.h
+++ b/chrome/browser/download/download_test_observer.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -66,9 +66,10 @@ class DownloadTestObserver : public content::DownloadManager::Observer,
   virtual void OnDownloadOpened(content::DownloadItem* download) OVERRIDE {}
 
   // content::DownloadManager::Observer
-  virtual void ModelChanged() OVERRIDE;
+  virtual void ModelChanged(content::DownloadManager* manager) OVERRIDE;
 
-  virtual void SelectFileDialogDisplayed(int32 id) OVERRIDE;
+  virtual void SelectFileDialogDisplayed(
+      content::DownloadManager* manager, int32 id) OVERRIDE;
 
   size_t NumDangerousDownloadsSeen() const;
 
@@ -150,7 +151,7 @@ class DownloadTestFlushObserver
   void WaitForFlush();
 
   // DownloadsManager observer methods.
-  virtual void ModelChanged() OVERRIDE;
+  virtual void ModelChanged(content::DownloadManager* manager) OVERRIDE;
 
   // DownloadItem observer methods.
   virtual void OnDownloadUpdated(content::DownloadItem* download) OVERRIDE;
diff --git a/chrome/browser/history/history_database.h b/chrome/browser/history/history_database.h
index 70f3693..9a25949 100644
--- a/chrome/browser/history/history_database.h
+++ b/chrome/browser/history/history_database.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -92,7 +92,7 @@ class HistoryDatabase : public DownloadDatabase,
   //
   // We don't delete the downloads table, since there may be in progress
   // downloads. We handle the download history clean up separately in:
-  // DownloadManager::RemoveDownloadsFromHistoryBetween.
+  // content::DownloadManager::RemoveDownloadsFromHistoryBetween.
   //
   // Returns true on success. On failure, the caller should assume that the
   // database is invalid. There could have been an error recreating a table.
diff --git a/chrome/browser/ui/cocoa/download/download_item_mac.h b/chrome/browser/ui/cocoa/download/download_item_mac.h
index 6b352de..9387f0a 100644
--- a/chrome/browser/ui/cocoa/download/download_item_mac.h
+++ b/chrome/browser/ui/cocoa/download/download_item_mac.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -35,7 +35,7 @@ class DownloadItemMac : content::DownloadItem::Observer {
   // Destructor.
   virtual ~DownloadItemMac();
 
-  // DownloadItem::Observer implementation
+  // content::DownloadItem::Observer implementation
   virtual void OnDownloadUpdated(content::DownloadItem* download) OVERRIDE;
   virtual void OnDownloadOpened(content::DownloadItem* download) OVERRIDE;
 
diff --git a/chrome/browser/ui/gtk/download/download_item_gtk.h b/chrome/browser/ui/gtk/download/download_item_gtk.h
index bb7a98e..eec8f52 100644
--- a/chrome/browser/ui/gtk/download/download_item_gtk.h
+++ b/chrome/browser/ui/gtk/download/download_item_gtk.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -48,7 +48,7 @@ class DownloadItemGtk : public content::DownloadItem::Observer,
   // Destroys all widgets belonging to this DownloadItemGtk.
   virtual ~DownloadItemGtk();
 
-  // DownloadItem::Observer implementation.
+  // content::DownloadItem::Observer implementation.
   virtual void OnDownloadUpdated(content::DownloadItem* download) OVERRIDE;
   virtual void OnDownloadOpened(content::DownloadItem* download) OVERRIDE { }
 
diff --git a/chrome/browser/ui/panels/panel_browsertest.cc b/chrome/browser/ui/panels/panel_browsertest.cc
index 87c7693..1c4bbd1 100644
--- a/chrome/browser/ui/panels/panel_browsertest.cc
+++ b/chrome/browser/ui/panels/panel_browsertest.cc
@@ -1718,7 +1718,9 @@ class DownloadObserver : public content::DownloadManager::Observer {
   }
 
   // DownloadManager::Observer
-  virtual void ModelChanged() {
+  virtual void ModelChanged(DownloadManager* manager) {
+    DCHECK_EQ(download_manager_, manager);
+
     std::vector<DownloadItem*> downloads;
     download_manager_->SearchDownloads(string16(), &downloads);
     if (downloads.empty())
diff --git a/chrome/browser/ui/views/download/download_item_view.cc b/chrome/browser/ui/views/download/download_item_view.cc
index c77c613..de29596 100644
--- a/chrome/browser/ui/views/download/download_item_view.cc
+++ b/chrome/browser/ui/views/download/download_item_view.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -252,7 +252,7 @@ void DownloadItemView::OnExtractIconComplete(IconManager::Handle handle,
 
 // Update the progress graphic on the icon and our text status label
 // to reflect our current bytes downloaded, time remaining.
-void DownloadItemView::OnDownloadUpdated(content::DownloadItem* download) {
+void DownloadItemView::OnDownloadUpdated(DownloadItem* download) {
   DCHECK(download == download_);
 
   if (IsShowingWarningDialog() &&
@@ -315,7 +315,7 @@ void DownloadItemView::OnDownloadUpdated(content::DownloadItem* download) {
   parent()->SchedulePaint();
 }
 
-void DownloadItemView::OnDownloadOpened(content::DownloadItem* download) {
+void DownloadItemView::OnDownloadOpened(DownloadItem* download) {
   disabled_while_opening_ = true;
   SetEnabled(false);
   MessageLoop::current()->PostDelayedTask(
diff --git a/chrome/browser/ui/webui/active_downloads_ui.cc b/chrome/browser/ui/webui/active_downloads_ui.cc
index d12bd50..f68020d 100644
--- a/chrome/browser/ui/webui/active_downloads_ui.cc
+++ b/chrome/browser/ui/webui/active_downloads_ui.cc
@@ -137,7 +137,7 @@ class ActiveDownloadsHandler
   virtual void OnDownloadOpened(DownloadItem* item) OVERRIDE { }
 
   // DownloadManager::Observer interface.
-  virtual void ModelChanged() OVERRIDE;
+  virtual void ModelChanged(DownloadManager* manager) OVERRIDE;
 
   // WebUI Callbacks.
   void HandleGetDownloads(const ListValue* args);
@@ -247,7 +247,7 @@ void ActiveDownloadsHandler::ViewFile(const ListValue* args) {
                               false);
 }
 
-void ActiveDownloadsHandler::ModelChanged() {
+void ActiveDownloadsHandler::ModelChanged(DownloadManager* manager) {
   UpdateDownloadList();
 }
 
diff --git a/chrome/browser/ui/webui/downloads_dom_handler.cc b/chrome/browser/ui/webui/downloads_dom_handler.cc
index d93c50c..b340c08 100644
--- a/chrome/browser/ui/webui/downloads_dom_handler.cc
+++ b/chrome/browser/ui/webui/downloads_dom_handler.cc
@@ -44,8 +44,6 @@
 #endif
 
 using content::BrowserThread;
-using content::DownloadItem;
-using content::DownloadManager;
 using content::UserMetricsAction;
 
 namespace {
@@ -55,11 +53,12 @@ namespace {
 static const int kMaxDownloads = 150;
 
 // Sort DownloadItems into descending order by their start time.
-class DownloadItemSorter : public std::binary_function<DownloadItem*,
-                                                       DownloadItem*,
+class DownloadItemSorter : public std::binary_function<content::DownloadItem*,
+                                                       content::DownloadItem*,
                                                        bool> {
  public:
-  bool operator()(const DownloadItem* lhs, const DownloadItem* rhs) {
+  bool operator()(const content::DownloadItem* lhs,
+                  const content::DownloadItem* rhs) {
     return lhs->GetStartTime() > rhs->GetStartTime();
   }
 };
@@ -87,66 +86,37 @@ void CountDownloadsDOMEvents(DownloadsDOMEvent event) {
 
 }  // namespace
 
-class DownloadsDOMHandler::OriginalDownloadManagerObserver
-    : public content::DownloadManager::Observer {
- public:
-  explicit OriginalDownloadManagerObserver(
-      DownloadManager::Observer* observer,
-      Profile* original_profile)
-      : observer_(observer) {
-    original_profile_download_manager_ =
-        DownloadServiceFactory::GetForProfile(
-            original_profile)->GetDownloadManager();
-    original_profile_download_manager_->AddObserver(this);
-  }
-
-  virtual ~OriginalDownloadManagerObserver() {
-    if (original_profile_download_manager_)
-      original_profile_download_manager_->RemoveObserver(this);
-  }
-
-  // Observer interface.
-  virtual void ModelChanged() {
-    observer_->ModelChanged();
-  }
-
-  virtual void ManagerGoingDown() {
-    original_profile_download_manager_ = NULL;
-  }
-
- private:
-  // The DownloadsDOMHandler for the off-the-record profile.
-  DownloadManager::Observer* observer_;
-
-  // The original profile's download manager.
-  DownloadManager* original_profile_download_manager_;
-};
-
-DownloadsDOMHandler::DownloadsDOMHandler(DownloadManager* dlm)
+DownloadsDOMHandler::DownloadsDOMHandler(content::DownloadManager* dlm)
     : search_text_(),
-      download_manager_(dlm) {
+      download_manager_(dlm),
+      original_profile_download_manager_(NULL) {
   // Create our fileicon data source.
   Profile::FromBrowserContext(dlm->GetBrowserContext())->
       GetChromeURLDataManager()->AddDataSource(new FileIconSource());
+
+  // Figure out our parent DownloadManager, if any.
+  Profile* profile =
+      Profile::FromBrowserContext(download_manager_->GetBrowserContext());
+  Profile* original_profile = profile->GetOriginalProfile();
+  if (original_profile != profile) {
+    original_profile_download_manager_ = DownloadServiceFactory::GetForProfile(
+        original_profile)->GetDownloadManager();
+  }
 }
 
 DownloadsDOMHandler::~DownloadsDOMHandler() {
   ClearDownloadItems();
   download_manager_->RemoveObserver(this);
+  if (original_profile_download_manager_)
+    original_profile_download_manager_->RemoveObserver(this);
 }
 
 // DownloadsDOMHandler, public: -----------------------------------------------
 
 void DownloadsDOMHandler::Init() {
   download_manager_->AddObserver(this);
-
-  Profile* profile =
-      Profile::FromBrowserContext(download_manager_->GetBrowserContext());
-  Profile* original_profile = profile->GetOriginalProfile();
-  if (original_profile != profile) {
-    original_download_manager_observer_.reset(
-        new OriginalDownloadManagerObserver(this, original_profile));
-  }
+  if (original_profile_download_manager_)
+    original_profile_download_manager_->AddObserver(this);
 }
 
 void DownloadsDOMHandler::RegisterMessages() {
@@ -199,7 +169,7 @@ void DownloadsDOMHandler::OnDownloadUpdated(content::DownloadItem* download) {
   if (it == download_items_.end())
     return;
 
-  if (download->GetState() == DownloadItem::REMOVING) {
+  if (download->GetState() == content::DownloadItem::REMOVING) {
     (*it)->RemoveObserver(this);
     *it = NULL;
     // A later ModelChanged() notification will change the WebUI's
@@ -216,17 +186,18 @@ void DownloadsDOMHandler::OnDownloadUpdated(content::DownloadItem* download) {
 
 // A download has started or been deleted. Query our DownloadManager for the
 // current set of downloads.
-void DownloadsDOMHandler::ModelChanged() {
+void DownloadsDOMHandler::ModelChanged(content::DownloadManager* manager) {
+  DCHECK(manager == download_manager_ ||
+         manager == original_profile_download_manager_);
+
   ClearDownloadItems();
   download_manager_->SearchDownloads(WideToUTF16(search_text_),
                                      &download_items_);
-  // If we have a parent profile, let it add its downloads to the results.
-  Profile* profile =
-      Profile::FromBrowserContext(download_manager_->GetBrowserContext());
-  if (profile->GetOriginalProfile() != profile) {
-    DownloadServiceFactory::GetForProfile(
-        profile->GetOriginalProfile())->GetDownloadManager()->SearchDownloads(
-            WideToUTF16(search_text_), &download_items_);
+  // If we have a parent DownloadManager, let it add its downloads to the
+  // results.
+  if (original_profile_download_manager_) {
+    original_profile_download_manager_->SearchDownloads(
+        WideToUTF16(search_text_), &download_items_);
   }
 
   sort(download_items_.begin(), download_items_.end(), DownloadItemSorter());
@@ -249,7 +220,7 @@ void DownloadsDOMHandler::ModelChanged() {
     // fixed.
     // We should never see anything that isn't already in the history.
     CHECK(*it);
-    CHECK_NE(DownloadItem::kUninitializedHandle, (*it)->GetDbHandle());
+    CHECK_NE(content::DownloadItem::kUninitializedHandle, (*it)->GetDbHandle());
 
     (*it)->AddObserver(this);
   }
@@ -257,12 +228,22 @@ void DownloadsDOMHandler::ModelChanged() {
   SendCurrentDownloads();
 }
 
+void DownloadsDOMHandler::ManagerGoingDown(content::DownloadManager* manager) {
+  // This should never happen.  The lifetime of the DownloadsDOMHandler
+  // is tied to the tab in which downloads.html is displayed, which cannot
+  // outlive the Browser that contains it, which cannot outlive the Profile
+  // it is associated with.  If that profile is an incognito profile,
+  // it cannot outlive its original profile.  Thus this class should be
+  // destroyed before a ManagerGoingDown() notification occurs.
+  NOTREACHED();
+}
+
 void DownloadsDOMHandler::HandleGetDownloads(const ListValue* args) {
   CountDownloadsDOMEvents(DOWNLOADS_DOM_EVENT_GET_DOWNLOADS);
   std::wstring new_search = UTF16ToWideHack(ExtractStringValue(args));
   if (search_text_.compare(new_search) != 0) {
     search_text_ = new_search;
-    ModelChanged();
+    ModelChanged(download_manager_);
   } else {
     SendCurrentDownloads();
   }
@@ -272,14 +253,14 @@ void DownloadsDOMHandler::HandleGetDownloads(const ListValue* args) {
 
 void DownloadsDOMHandler::HandleOpenFile(const ListValue* args) {
   CountDownloadsDOMEvents(DOWNLOADS_DOM_EVENT_OPEN_FILE);
-  DownloadItem* file = GetDownloadByValue(args);
+  content::DownloadItem* file = GetDownloadByValue(args);
   if (file)
     file->OpenDownload();
 }
 
 void DownloadsDOMHandler::HandleDrag(const ListValue* args) {
   CountDownloadsDOMEvents(DOWNLOADS_DOM_EVENT_DRAG);
-  DownloadItem* file = GetDownloadByValue(args);
+  content::DownloadItem* file = GetDownloadByValue(args);
   if (file) {
     IconManager* im = g_browser_process->icon_manager();
     gfx::Image* icon = im->LookupIcon(file->GetUserVerifiedFilePath(),
@@ -295,45 +276,45 @@ void DownloadsDOMHandler::HandleDrag(const ListValue* args) {
 
 void DownloadsDOMHandler::HandleSaveDangerous(const ListValue* args) {
   CountDownloadsDOMEvents(DOWNLOADS_DOM_EVENT_SAVE_DANGEROUS);
-  DownloadItem* file = GetDownloadByValue(args);
+  content::DownloadItem* file = GetDownloadByValue(args);
   if (file)
     file->DangerousDownloadValidated();
 }
 
 void DownloadsDOMHandler::HandleDiscardDangerous(const ListValue* args) {
   CountDownloadsDOMEvents(DOWNLOADS_DOM_EVENT_DISCARD_DANGEROUS);
-  DownloadItem* file = GetDownloadByValue(args);
+  content::DownloadItem* file = GetDownloadByValue(args);
   if (file)
-    file->Delete(DownloadItem::DELETE_DUE_TO_USER_DISCARD);
+    file->Delete(content::DownloadItem::DELETE_DUE_TO_USER_DISCARD);
 }
 
 void DownloadsDOMHandler::HandleShow(const ListValue* args) {
   CountDownloadsDOMEvents(DOWNLOADS_DOM_EVENT_SHOW);
-  DownloadItem* file = GetDownloadByValue(args);
+  content::DownloadItem* file = GetDownloadByValue(args);
   if (file)
     file->ShowDownloadInShell();
 }
 
 void DownloadsDOMHandler::HandlePause(const ListValue* args) {
   CountDownloadsDOMEvents(DOWNLOADS_DOM_EVENT_PAUSE);
-  DownloadItem* file = GetDownloadByValue(args);
+  content::DownloadItem* file = GetDownloadByValue(args);
   if (file)
     file->TogglePause();
 }
 
 void DownloadsDOMHandler::HandleRemove(const ListValue* args) {
   CountDownloadsDOMEvents(DOWNLOADS_DOM_EVENT_REMOVE);
-  DownloadItem* file = GetDownloadByValue(args);
+  content::DownloadItem* file = GetDownloadByValue(args);
   if (file) {
     // TODO(rdsmith): Change to DCHECK when http://crbug.com/85408 is fixed.
-    CHECK_NE(DownloadItem::kUninitializedHandle, file->GetDbHandle());
+    CHECK_NE(content::DownloadItem::kUninitializedHandle, file->GetDbHandle());
     file->Remove();
   }
 }
 
 void DownloadsDOMHandler::HandleCancel(const ListValue* args) {
   CountDownloadsDOMEvents(DOWNLOADS_DOM_EVENT_CANCEL);
-  DownloadItem* file = GetDownloadByValue(args);
+  content::DownloadItem* file = GetDownloadByValue(args);
   if (file)
     file->Cancel(true);
 }
@@ -342,14 +323,10 @@ void DownloadsDOMHandler::HandleClearAll(const ListValue* args) {
   CountDownloadsDOMEvents(DOWNLOADS_DOM_EVENT_CLEAR_ALL);
   download_manager_->RemoveAllDownloads();
 
-  Profile* profile =
-      Profile::FromBrowserContext(download_manager_->GetBrowserContext());
   // If this is an incognito downloader, clear All should clear main download
   // manager as well.
-  if (profile->GetOriginalProfile() != profile)
-    DownloadServiceFactory::GetForProfile(
-        profile->GetOriginalProfile())->
-            GetDownloadManager()->RemoveAllDownloads();
+  if (original_profile_download_manager_)
+    original_profile_download_manager_->RemoveAllDownloads();
 }
 
 void DownloadsDOMHandler::HandleOpenDownloadsFolder(const ListValue* args) {
@@ -386,7 +363,7 @@ void DownloadsDOMHandler::ClearDownloadItems() {
   download_items_.clear();
 }
 
-DownloadItem* DownloadsDOMHandler::GetDownloadById(int id) {
+content::DownloadItem* DownloadsDOMHandler::GetDownloadById(int id) {
   for (OrderedDownloads::iterator it = download_items_.begin();
       it != download_items_.end(); ++it) {
     if (static_cast<int>(it - download_items_.begin() == id)) {
@@ -397,7 +374,8 @@ DownloadItem* DownloadsDOMHandler::GetDownloadById(int id) {
   return NULL;
 }
 
-DownloadItem* DownloadsDOMHandler::GetDownloadByValue(const ListValue* args) {
+content::DownloadItem* DownloadsDOMHandler::GetDownloadByValue(
+    const ListValue* args) {
   int id;
   if (ExtractIntegerValue(args, &id)) {
     return GetDownloadById(id);
diff --git a/chrome/browser/ui/webui/downloads_dom_handler.h b/chrome/browser/ui/webui/downloads_dom_handler.h
index d603094..e7ee3c7 100644
--- a/chrome/browser/ui/webui/downloads_dom_handler.h
+++ b/chrome/browser/ui/webui/downloads_dom_handler.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -31,12 +31,13 @@ class DownloadsDOMHandler : public content::WebUIMessageHandler,
   // WebUIMessageHandler implementation.
   virtual void RegisterMessages() OVERRIDE;
 
-  // DownloadItem::Observer interface
+  // content::DownloadItem::Observer interface
   virtual void OnDownloadUpdated(content::DownloadItem* download) OVERRIDE;
   virtual void OnDownloadOpened(content::DownloadItem* download) OVERRIDE { }
 
-  // DownloadManager::Observer interface
-  virtual void ModelChanged() OVERRIDE;
+  // content::DownloadManager::Observer interface
+  virtual void ModelChanged(content::DownloadManager* manager) OVERRIDE;
+  virtual void ManagerGoingDown(content::DownloadManager* manager) OVERRIDE;
 
   // Callback for the "getDownloads" message.
   void HandleGetDownloads(const base::ListValue* args);
@@ -96,10 +97,10 @@ class DownloadsDOMHandler : public content::WebUIMessageHandler,
   // Our model
   content::DownloadManager* download_manager_;
 
-  // The downloads webui for an off-the-record window also shows downloads from
-  // the parent profile.
-  scoped_ptr<OriginalDownloadManagerObserver>
-      original_download_manager_observer_;
+  // If |download_manager_| belongs to an incognito profile than this
+  // is the DownloadManager for the original profile; otherwise, this is
+  // NULL.
+  content::DownloadManager* original_profile_download_manager_;
 
   // The current set of visible DownloadItems for this view received from the
   // DownloadManager. DownloadManager owns the DownloadItems. The vector is
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 127425f..211337c 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -948,6 +948,8 @@
         'browser/download/download_shelf_context_menu.cc',
         'browser/download/download_shelf_context_menu.h',
         'browser/download/download_started_animation.h',
+        'browser/download/download_status_updater.cc',
+        'browser/download/download_status_updater.h',
         'browser/download/download_throttling_resource_handler.cc',
         'browser/download/download_throttling_resource_handler.h',
         'browser/download/download_util.cc',
diff --git a/chrome/chrome_tests.gypi b/chrome/chrome_tests.gypi
index b4bcac5..cd0a070 100644
--- a/chrome/chrome_tests.gypi
+++ b/chrome/chrome_tests.gypi
@@ -1398,6 +1398,7 @@
         'browser/download/download_request_infobar_delegate_unittest.cc',
         'browser/download/download_request_limiter_unittest.cc',
         'browser/download/download_shelf_unittest.cc',
+        'browser/download/download_status_updater_unittest.cc',
         'browser/enumerate_modules_model_unittest_win.cc',
         'browser/event_disposition.cc',
         'browser/event_disposition.h',