Refactor DragDownloadFile so that it can be used by both Windows and MacOSX.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/572014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@38545 0039d316-1c4b-4281-b951-d872f2087c98

28 files changed, 651 insertions, 481 deletions

diff --git a/app/app_base.gypi b/app/app_base.gypi
index daa2f52..fdc8854 100644
--- a/app/app_base.gypi
+++ b/app/app_base.gypi
@@ -106,6 +106,7 @@
         'drag_drop_types_gtk.cc',
         'drag_drop_types_win.cc',
         'drag_drop_types.h',
+        'file_download_interface.h',
         'gfx/blit.cc',
         'gfx/blit.h',
         'gfx/canvas.cc',
diff --git a/app/download_file_interface.h b/app/download_file_interface.h
new file mode 100644
index 0000000..13d2dcf
--- /dev/null
+++ b/app/download_file_interface.h
@@ -0,0 +1,46 @@
+// Copyright (c) 2009 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 APP_DOWNLOAD_FILE_INTERFACE_H_
+#define APP_DOWNLOAD_FILE_INTERFACE_H_
+
+#include "build/build_config.h"
+
+#include "base/basictypes.h"
+#include "base/ref_counted.h"
+
+#if defined(OS_WIN)
+#include <objidl.h>
+#endif
+
+class FilePath;
+
+// Defines the interface to observe the status of file download.
+class DownloadFileObserver
+    : public base::RefCountedThreadSafe<DownloadFileObserver> {
+ public:
+  virtual void OnDownloadCompleted(const FilePath& file_path) = 0;
+  virtual void OnDownloadAborted() = 0;
+
+ protected:
+  friend class base::RefCountedThreadSafe<DownloadFileObserver>;
+  virtual ~DownloadFileObserver() {}
+};
+
+// Defines the interface to control how a file is downloaded.
+class DownloadFileProvider
+    : public base::RefCountedThreadSafe<DownloadFileProvider> {
+ public:
+  virtual bool Start(DownloadFileObserver* observer) = 0;
+  virtual void Stop() = 0;
+#if defined(OS_WIN)
+  virtual IStream* GetStream() = 0;
+#endif
+
+ protected:
+  friend class base::RefCountedThreadSafe<DownloadFileProvider>;
+  virtual ~DownloadFileProvider() {}
+};
+
+#endif  // APP_DOWNLOAD_FILE_INTERFACE_H_
diff --git a/app/os_exchange_data.cc b/app/os_exchange_data.cc
index dc57cd1..8081f37 100644
--- a/app/os_exchange_data.cc
+++ b/app/os_exchange_data.cc
@@ -129,7 +129,7 @@ bool OSExchangeData::GetHtml(std::wstring* html, GURL* base_url) const {
   return provider_->GetHtml(html, base_url);
 }
 
-void OSExchangeData::SetDownloadFileInfo(DownloadFileInfo* download) {
+void OSExchangeData::SetDownloadFileInfo(const DownloadFileInfo& download) {
   return provider_->SetDownloadFileInfo(download);
 }
 #endif
diff --git a/app/os_exchange_data.h b/app/os_exchange_data.h
index b38e655..316db88 100644
--- a/app/os_exchange_data.h
+++ b/app/os_exchange_data.h
@@ -17,9 +17,9 @@
 #include <gtk/gtk.h>
 #endif
 
+#include "app/download_file_interface.h"
 #include "base/basictypes.h"
 #include "base/file_path.h"
-#include "base/ref_counted.h"
 #include "base/scoped_ptr.h"
 
 class GURL;
@@ -61,45 +61,13 @@ class OSExchangeData {
 #endif
   };
 
-  struct DownloadFileInfo;
-
-  // Defines the interface to observe the status of file download.
-  class DownloadFileObserver : public base::RefCounted<DownloadFileObserver> {
-   public:
-    // The caller is responsible to free the DownloadFileInfo objects passed
-    // in the vector parameter.
-    virtual void OnDataReady(
-        int format,
-        const std::vector<DownloadFileInfo*>& downloads) = 0;
-
-   protected:
-    friend class base::RefCounted<DownloadFileObserver>;
-    virtual ~DownloadFileObserver() {}
-  };
-
-  // Defines the interface to control how a file is downloaded.
-  class DownloadFileProvider :
-      public base::RefCountedThreadSafe<DownloadFileProvider> {
-   public:
-    virtual bool Start(DownloadFileObserver* observer, int format) = 0;
-    virtual void Stop() = 0;
-
-   protected:
-    friend class base::RefCountedThreadSafe<DownloadFileProvider>;
-    virtual ~DownloadFileProvider() {}
-  };
-
   // Encapsulates the info about a file to be downloaded.
   struct DownloadFileInfo {
     FilePath filename;
-    uint64 size;
     scoped_refptr<DownloadFileProvider> downloader;
 
-    DownloadFileInfo(const FilePath& filename,
-                     uint64 size,
-                     DownloadFileProvider* downloader)
+    DownloadFileInfo(const FilePath& filename, DownloadFileProvider* downloader)
         : filename(filename),
-          size(size),
           downloader(downloader) {}
   };
 
@@ -135,7 +103,7 @@ class OSExchangeData {
     virtual bool GetHtml(std::wstring* html, GURL* base_url) const = 0;
     virtual bool HasFileContents() const = 0;
     virtual bool HasHtml() const = 0;
-    virtual void SetDownloadFileInfo(DownloadFileInfo* download) = 0;
+    virtual void SetDownloadFileInfo(const DownloadFileInfo& download) = 0;
 #endif
   };
 
@@ -211,7 +179,7 @@ class OSExchangeData {
   bool GetHtml(std::wstring* html, GURL* base_url) const;
 
   // Adds a download file with full path (CF_HDROP).
-  void SetDownloadFileInfo(DownloadFileInfo* download);
+  void SetDownloadFileInfo(const DownloadFileInfo& download);
 #endif
 
  private:
diff --git a/app/os_exchange_data_provider_win.cc b/app/os_exchange_data_provider_win.cc
index dc28597..8f953d1 100644
--- a/app/os_exchange_data_provider_win.cc
+++ b/app/os_exchange_data_provider_win.cc
@@ -455,17 +455,17 @@ bool OSExchangeDataProviderWin::HasCustomFormat(CLIPFORMAT format) const {
 }
 
 void OSExchangeDataProviderWin::SetDownloadFileInfo(
-    OSExchangeData::DownloadFileInfo* download) {
+    const OSExchangeData::DownloadFileInfo& download) {
   // If the filename is not provided, set stoarge to NULL to indicate that
   // the delay rendering will be used.
   STGMEDIUM* storage = NULL;
-  if (!download->filename.empty())
-    storage = GetStorageForFileName(download->filename.value());
+  if (!download.filename.empty())
+    storage = GetStorageForFileName(download.filename.value());
 
   // Add CF_HDROP.
   DataObjectImpl::StoredDataInfo* info = new DataObjectImpl::StoredDataInfo(
       ClipboardUtil::GetCFHDropFormat()->cfFormat, storage);
-  info->downloads.push_back(download);
+  info->downloader = download.downloader;
   data_->contents_.push_back(info);
 }
 
@@ -560,35 +560,18 @@ DataObjectImpl::~DataObjectImpl() {
 void DataObjectImpl::StopDownloads() {
   for (StoredData::iterator iter = contents_.begin();
        iter != contents_.end(); ++iter) {
-    for (size_t i = 0; i < (*iter)->downloads.size(); ++i) {
-      if ((*iter)->downloads[i]->downloader) {
-        (*iter)->downloads[i]->downloader->Stop();
-        (*iter)->downloads[i]->downloader = 0;
-      }
-      delete (*iter)->downloads[i];
+    if ((*iter)->downloader.get()) {
+      (*iter)->downloader->Stop();
+      (*iter)->downloader = 0;
     }
-    (*iter)->downloads.clear();
   }
 }
 
-void DataObjectImpl::OnDataReady(
-    int format,
-    const std::vector<OSExchangeData::DownloadFileInfo*>& downloads) {
-  // Find and update the data corresponding to the format.
-  CLIPFORMAT clip_format = static_cast<CLIPFORMAT>(format);
-  DCHECK(clip_format == ClipboardUtil::GetCFHDropFormat()->cfFormat);
+void DataObjectImpl::OnDownloadCompleted(const FilePath& file_path) {
+  CLIPFORMAT hdrop_format = ClipboardUtil::GetCFHDropFormat()->cfFormat;
   DataObjectImpl::StoredData::iterator iter = contents_.begin();
   for (; iter != contents_.end(); ++iter) {
-    if ((*iter)->format_etc.cfFormat == clip_format) {
-      // Update the downloads.
-      DCHECK(downloads.size() == (*iter)->downloads.size());
-      for (size_t i = 0; i < (*iter)->downloads.size(); ++i) {
-        OSExchangeData::DownloadFileInfo* old_download = (*iter)->downloads[i];
-        (*iter)->downloads[i] = downloads[i];
-        (*iter)->downloads[i]->downloader = old_download->downloader;
-        delete old_download;
-      }
-
+    if ((*iter)->format_etc.cfFormat == hdrop_format) {
       // Release the old storage.
       if ((*iter)->owns_medium) {
         ReleaseStgMedium((*iter)->medium);
@@ -597,7 +580,7 @@ void DataObjectImpl::OnDataReady(
 
       // Update the storage.
       (*iter)->owns_medium = true;
-      (*iter)->medium = GetStorageForFileName(downloads[0]->filename.value());
+      (*iter)->medium = GetStorageForFileName(file_path.value());
 
       break;
     }
@@ -605,6 +588,9 @@ void DataObjectImpl::OnDataReady(
   DCHECK(iter != contents_.end());
 }
 
+void DataObjectImpl::OnDownloadAborted() {
+}
+
 HRESULT DataObjectImpl::GetData(FORMATETC* format_etc, STGMEDIUM* medium) {
   if (is_aborting_)
     return DV_E_FORMATETC;
@@ -629,7 +615,12 @@ HRESULT DataObjectImpl::GetData(FORMATETC* format_etc, STGMEDIUM* medium) {
           if (is_left_button_down)
             return DV_E_FORMATETC;
 
-          wait_for_data = true;
+          // In async mode, we do not want to start waiting for the data before
+          // the async operation is started. This is because we want to postpone
+          // until Shell kicks off a background thread to do the work so that
+          // we do not block the UI thread.
+          if (!in_async_mode_ || async_operation_started_)
+            wait_for_data = true;
         } else {
           // If the left button is up and the target has not requested the data
           // yet, it probably means that the target does not support delay-
@@ -648,18 +639,11 @@ HRESULT DataObjectImpl::GetData(FORMATETC* format_etc, STGMEDIUM* medium) {
           if (observer_)
             observer_->OnWaitForData();
 
-          // Now we can start the downloads. Each download will wait till the
-          // necessary data is ready and then return the control.
-          for (size_t i = 0; i < (*iter)->downloads.size(); ++i) {
-            if ((*iter)->downloads[i]->downloader) {
-              if (!(*iter)->downloads[i]->downloader->Start(
-                     this, format_etc->cfFormat)) {
-                // If any of the download fails to start, abort the whole
-                // process.
-                is_aborting_ = true;
-                StopDownloads();
-                return DV_E_FORMATETC;
-              }
+          // Now we can start the download.
+          if ((*iter)->downloader.get()) {
+            if (!(*iter)->downloader->Start(this)) {
+              is_aborting_ = true;
+              return DV_E_FORMATETC;
             }
           }
 
@@ -788,12 +772,12 @@ HRESULT DataObjectImpl::QueryInterface(const IID& iid, void** object) {
 }
 
 ULONG DataObjectImpl::AddRef() {
-  base::RefCounted<OSExchangeData::DownloadFileObserver>::AddRef();
+  base::RefCountedThreadSafe<DownloadFileObserver>::AddRef();
   return 0;
 }
 
 ULONG DataObjectImpl::Release() {
-  base::RefCounted<OSExchangeData::DownloadFileObserver>::Release();
+  base::RefCountedThreadSafe<DownloadFileObserver>::Release();
   return 0;
 }
 
@@ -918,6 +902,7 @@ static STGMEDIUM* GetStorageForFileDescriptor(
   return storage;
 }
 
+
 ///////////////////////////////////////////////////////////////////////////////
 // OSExchangeData, public:
 
diff --git a/app/os_exchange_data_provider_win.h b/app/os_exchange_data_provider_win.h
index 4bd0d80..6ea014b 100644
--- a/app/os_exchange_data_provider_win.h
+++ b/app/os_exchange_data_provider_win.h
@@ -12,7 +12,7 @@
 #include "app/os_exchange_data.h"
 #include "base/scoped_comptr_win.h"
 
-class DataObjectImpl : public OSExchangeData::DownloadFileObserver,
+class DataObjectImpl : public DownloadFileObserver,
                        public IDataObject,
                        public IAsyncOperation {
  public:
@@ -30,9 +30,8 @@ class DataObjectImpl : public OSExchangeData::DownloadFileObserver,
   void set_observer(Observer* observer) { observer_ = observer; }
 
   // DownloadFileObserver implementation:
-  virtual void OnDataReady(
-      int format,
-      const std::vector<OSExchangeData::DownloadFileInfo*>& downloads);
+  virtual void OnDownloadCompleted(const FilePath& file_path);
+  virtual void OnDownloadAborted();
 
   // IDataObject implementation:
   HRESULT __stdcall GetData(FORMATETC* format_etc, STGMEDIUM* medium);
@@ -77,7 +76,7 @@ class DataObjectImpl : public OSExchangeData::DownloadFileObserver,
     STGMEDIUM* medium;
     bool owns_medium;
     bool in_delay_rendering;
-    std::vector<OSExchangeData::DownloadFileInfo*> downloads;
+    scoped_refptr<DownloadFileProvider> downloader;
 
     StoredDataInfo(CLIPFORMAT cf, STGMEDIUM* medium)
         : medium(medium),
@@ -102,11 +101,8 @@ class DataObjectImpl : public OSExchangeData::DownloadFileObserver,
         ReleaseStgMedium(medium);
         delete medium;
       }
-      for (size_t i = 0; i < downloads.size(); ++i) {
-        if (downloads[i]->downloader)
-          downloads[i]->downloader->Stop();
-      }
-      downloads.clear();
+      if (downloader.get())
+        downloader->Stop();
     }
   };
 
@@ -167,7 +163,7 @@ class OSExchangeDataProviderWin : public OSExchangeData::Provider {
   virtual bool HasHtml() const;
   virtual bool HasCustomFormat(OSExchangeData::CustomFormat format) const;
   virtual void SetDownloadFileInfo(
-      OSExchangeData::DownloadFileInfo* download_info);
+      const OSExchangeData::DownloadFileInfo& download_info);
 
  private:
   scoped_refptr<DataObjectImpl> data_;
diff --git a/chrome/browser/download/download_file.cc b/chrome/browser/download/download_file.cc
index 25a0900..b152d18 100644
--- a/chrome/browser/download/download_file.cc
+++ b/chrome/browser/download/download_file.cc
@@ -57,7 +57,7 @@ class DownloadFileUpdateTask : public Task {
 // DownloadFile implementation -------------------------------------------------
 
 DownloadFile::DownloadFile(const DownloadCreateInfo* info)
-    : file_(NULL),
+    : file_stream_(info->save_info.file_stream),
       source_url_(info->url),
       referrer_url_(info->referrer_url),
       id_(info->download_id),
@@ -65,9 +65,11 @@ DownloadFile::DownloadFile(const DownloadCreateInfo* info)
       render_view_id_(info->render_view_id),
       request_id_(info->request_id),
       bytes_so_far_(0),
+      full_path_(info->save_info.file_path),
       path_renamed_(false),
       in_progress_(true),
-      dont_sleep_(true) {
+      dont_sleep_(true),
+      save_info_(info->save_info) {
 }
 
 DownloadFile::~DownloadFile() {
@@ -75,15 +77,15 @@ DownloadFile::~DownloadFile() {
 }
 
 bool DownloadFile::Initialize() {
-  if (file_util::CreateTemporaryFile(&full_path_))
-    return Open("wb");
+  if (!full_path_.empty() || file_util::CreateTemporaryFile(&full_path_))
+    return Open();
   return false;
 }
 
 bool DownloadFile::AppendDataToFile(const char* data, int data_len) {
-  if (file_) {
+  if (file_stream_.get()) {
     // FIXME bug 595247: handle errors on file writes.
-    size_t written = fwrite(data, 1, data_len, file_);
+    size_t written = file_stream_->Write(data, data_len, NULL);
     bytes_so_far_ += written;
     return true;
   }
@@ -92,13 +94,18 @@ bool DownloadFile::AppendDataToFile(const char* data, int data_len) {
 
 void DownloadFile::Cancel() {
   Close();
-  file_util::Delete(full_path_, false);
+  if (!full_path_.empty())
+    file_util::Delete(full_path_, false);
 }
 
 // The UI has provided us with our finalized name.
 bool DownloadFile::Rename(const FilePath& new_path) {
   Close();
 
+  // Nothing more to do if the new path is same as the old one.
+  if (new_path == full_path_)
+    return true;
+
 #if defined(OS_WIN)
   // We cannot rename because rename will keep the same security descriptor
   // on the destination file. We want to recreate the security descriptor
@@ -119,23 +126,30 @@ bool DownloadFile::Rename(const FilePath& new_path) {
   if (!in_progress_)
     return true;
 
-  if (!Open("a+b"))
+  if (!Open())
     return false;
   return true;
 }
 
 void DownloadFile::Close() {
-  if (file_) {
-    file_util::CloseFile(file_);
-    file_ = NULL;
+  if (file_stream_.get()) {
+    file_stream_->Close();
+    file_stream_.reset();
   }
 }
 
-bool DownloadFile::Open(const char* open_mode) {
+bool DownloadFile::Open() {
   DCHECK(!full_path_.empty());
-  file_ = file_util::OpenFile(full_path_, open_mode);
-  if (!file_) {
-    return false;
+
+  // Create a new file steram if it is not provided.
+  if (!file_stream_.get()) {
+    file_stream_.reset(new net::FileStream);
+    if (file_stream_->Open(full_path_,
+                          base::PLATFORM_FILE_OPEN_ALWAYS |
+                              base::PLATFORM_FILE_WRITE) != net::OK) {
+      file_stream_.reset();
+      return false;
+    }
   }
 
 #if defined(OS_WIN)
@@ -429,7 +443,7 @@ void DownloadFileManager::DownloadUrl(
     const GURL& url,
     const GURL& referrer,
     const std::string& referrer_charset,
-    const FilePath& save_file_path,
+    const DownloadSaveInfo& save_info,
     int render_process_host_id,
     int render_view_id,
     URLRequestContextGetter* request_context_getter) {
@@ -441,7 +455,7 @@ void DownloadFileManager::DownloadUrl(
                           url,
                           referrer,
                           referrer_charset,
-                          save_file_path,
+                          save_info,
                           render_process_host_id,
                           render_view_id,
                           request_context_getter));
@@ -526,7 +540,7 @@ void DownloadFileManager::OnDownloadUrl(
     const GURL& url,
     const GURL& referrer,
     const std::string& referrer_charset,
-    const FilePath& save_file_path,
+    const DownloadSaveInfo& save_info,
     int render_process_host_id,
     int render_view_id,
     URLRequestContextGetter* request_context_getter) {
@@ -537,7 +551,7 @@ void DownloadFileManager::OnDownloadUrl(
 
   resource_dispatcher_host_->BeginDownload(url,
                                            referrer,
-                                           save_file_path,
+                                           save_info,
                                            render_process_host_id,
                                            render_view_id,
                                            context);
diff --git a/chrome/browser/download/download_file.h b/chrome/browser/download/download_file.h
index 352f937..d4df8c4 100644
--- a/chrome/browser/download/download_file.h
+++ b/chrome/browser/download/download_file.h
@@ -49,11 +49,13 @@
 #include "base/basictypes.h"
 #include "base/file_path.h"
 #include "base/hash_tables.h"
+#include "base/linked_ptr.h"
 #include "base/lock.h"
 #include "base/ref_counted.h"
 #include "base/timer.h"
 #include "chrome/browser/power_save_blocker.h"
 #include "googleurl/src/gurl.h"
+#include "net/base/file_stream.h"
 
 namespace net {
 class IOBuffer;
@@ -78,6 +80,16 @@ struct DownloadBuffer {
   std::vector<Contents> contents;
 };
 
+// DownloadSaveInfo ------------------------------------------------------------
+
+// Holds the information about how to save a download file.
+struct DownloadSaveInfo {
+  FilePath file_path;
+  linked_ptr<net::FileStream> file_stream;
+
+  DownloadSaveInfo() { }
+};
+
 // DownloadFile ----------------------------------------------------------------
 
 // These objects live exclusively on the download thread and handle the writing
@@ -111,18 +123,18 @@ class DownloadFile {
   int render_view_id() const { return render_view_id_; }
   int request_id() const { return request_id_; }
   bool path_renamed() const { return path_renamed_; }
-  bool in_progress() const { return file_ != NULL; }
+  bool in_progress() const { return file_stream_ != NULL; }
   void set_in_progress(bool in_progress) { in_progress_ = in_progress; }
 
  private:
-  // Open or Close the OS file handle. The file is opened in the constructor
+  // Open or Close the OS file stream. The stream is opened in the constructor
   // based on creation information passed to it, and automatically closed in
   // the destructor.
   void Close();
-  bool Open(const char* open_mode);
+  bool Open();
 
-  // OS file handle for writing
-  FILE* file_;
+  // OS file stream for writing
+  linked_ptr<net::FileStream> file_stream_;
 
   // Source URL for the file being downloaded.
   GURL source_url_;
@@ -157,6 +169,9 @@ class DownloadFile {
   // RAII handle to keep the system from sleeping while we're downloading.
   PowerSaveBlocker dont_sleep_;
 
+  // The provider used to save the download data.
+  DownloadSaveInfo save_info_;
+
   DISALLOW_COPY_AND_ASSIGN(DownloadFile);
 };
 
@@ -192,7 +207,7 @@ class DownloadFileManager
   void DownloadUrl(const GURL& url,
                    const GURL& referrer,
                    const std::string& referrer_charset,
-                   const FilePath& save_file_path,
+                   const DownloadSaveInfo& save_info,
                    int render_process_host_id,
                    int render_view_id,
                    URLRequestContextGetter* request_context_getter);
@@ -201,7 +216,7 @@ class DownloadFileManager
   void OnDownloadUrl(const GURL& url,
                      const GURL& referrer,
                      const std::string& referrer_charset,
-                     const FilePath& save_file_path,
+                     const DownloadSaveInfo& save_info,
                      int render_process_host_id,
                      int render_view_id,
                      URLRequestContextGetter* request_context_getter);
diff --git a/chrome/browser/download/download_manager.cc b/chrome/browser/download/download_manager.cc
index 1248d94..a69703b 100644
--- a/chrome/browser/download/download_manager.cc
+++ b/chrome/browser/download/download_manager.cc
@@ -598,21 +598,22 @@ void DownloadManager::StartDownload(DownloadCreateInfo* info) {
       info->save_as = true;
   }
 
-  // Determine the proper path for a download, by either one of the following:
-  // 1) using the provided save file path.
-  // 2) using the default download directory.
-  // 3) prompting the user.
-  FilePath generated_name;
-  GenerateFileNameFromInfo(info, &generated_name);
-  if (!info->save_file_path.empty())
-    info->suggested_path = info->save_file_path;
-  else if (info->save_as && !last_download_path_.empty())
-    info->suggested_path = last_download_path_;
-  else
-    info->suggested_path = download_path();
-  info->suggested_path = info->suggested_path.Append(generated_name);
+  if (info->save_info.file_path.empty()) {
+    // Determine the proper path for a download, by either one of the following:
+    // 1) using the default download directory.
+    // 2) prompting the user.
+    FilePath generated_name;
+    GenerateFileNameFromInfo(info, &generated_name);
+    if (info->save_as && !last_download_path_.empty())
+      info->suggested_path = last_download_path_;
+    else
+      info->suggested_path = download_path();
+    info->suggested_path = info->suggested_path.Append(generated_name);
+  } else {
+    info->suggested_path = info->save_info.file_path;
+  }
 
-  if (!info->save_as && info->save_file_path.empty()) {
+  if (!info->save_as && info->save_info.file_path.empty()) {
     // Downloads can be marked as dangerous for two reasons:
     // a) They have a dangerous-looking filename
     // b) They are an extension that is not from the gallery
@@ -646,7 +647,10 @@ void DownloadManager::CheckIfSuggestedPathExists(DownloadCreateInfo* info) {
     info->suggested_path = info->suggested_path.Append(filename);
   }
 
-  info->path_uniquifier = GetUniquePathNumber(info->suggested_path);
+  // Do not add the path uniquifier if we are saving to a specific path as in
+  // the drag-out case.
+  if (info->save_info.file_path.empty())
+    info->path_uniquifier = GetUniquePathNumber(info->suggested_path);
 
   // If the download is deemed dangerous, we'll use a temporary name for it.
   if (info->is_dangerous) {
@@ -676,7 +680,7 @@ void DownloadManager::CheckIfSuggestedPathExists(DownloadCreateInfo* info) {
     }
   }
 
-  if (!info->save_as) {
+  if (!info->save_as && info->save_info.file_path.empty()) {
     // Create an empty file at the suggested path so that we don't allocate the
     // same "non-existant" path to multiple downloads.
     // See: http://code.google.com/p/chromium/issues/detail?id=3662
@@ -743,7 +747,7 @@ void DownloadManager::ContinueStartDownload(DownloadCreateInfo* info,
                                 info->is_dangerous,
                                 info->save_as,
                                 info->is_extension_install,
-                                !info->save_file_path.empty());
+                                !info->save_info.file_path.empty());
     download->set_manager(this);
     in_progress_[info->download_id] = download;
   } else {
@@ -1204,7 +1208,7 @@ void DownloadManager::DownloadUrl(const GURL& url,
   file_manager_->DownloadUrl(url,
                              referrer,
                              referrer_charset,
-                             FilePath(),
+                             DownloadSaveInfo(),
                              tab_contents->GetRenderProcessHost()->id(),
                              tab_contents->render_view_host()->routing_id(),
                              request_context_getter_);
@@ -1213,13 +1217,13 @@ void DownloadManager::DownloadUrl(const GURL& url,
 void DownloadManager::DownloadUrlToFile(const GURL& url,
                                         const GURL& referrer,
                                         const std::string& referrer_charset,
-                                        const FilePath& save_file_path,
+                                        const DownloadSaveInfo& save_info,
                                         TabContents* tab_contents) {
   DCHECK(tab_contents);
   file_manager_->DownloadUrl(url,
                              referrer,
                              referrer_charset,
-                             save_file_path,
+                             save_info,
                              tab_contents->GetRenderProcessHost()->id(),
                              tab_contents->render_view_host()->routing_id(),
                              request_context_getter_);
diff --git a/chrome/browser/download/download_manager.h b/chrome/browser/download/download_manager.h
index 4d7a709..3ab0a53 100644
--- a/chrome/browser/download/download_manager.h
+++ b/chrome/browser/download/download_manager.h
@@ -62,6 +62,7 @@ class Profile;
 class ResourceDispatcherHost;
 class URLRequestContextGetter;
 class TabContents;
+struct DownloadSaveInfo;
 
 namespace base {
 class Thread;
@@ -414,7 +415,7 @@ class DownloadManager : public base::RefCountedThreadSafe<DownloadManager>,
   void DownloadUrlToFile(const GURL& url,
                          const GURL& referrer,
                          const std::string& referrer_encoding,
-                         const FilePath& save_file_path,
+                         const DownloadSaveInfo& save_info,
                          TabContents* tab_contents);
 
   // Allow objects to observe the download creation process.
diff --git a/chrome/browser/download/drag_download_file.cc b/chrome/browser/download/drag_download_file.cc
new file mode 100644
index 0000000..e55ccf5
--- /dev/null
+++ b/chrome/browser/download/drag_download_file.cc
@@ -0,0 +1,223 @@
+// Copyright (c) 2009-2010 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/drag_download_file.h"
+
+#include "base/file_util.h"
+#include "base/message_loop.h"
+#include "chrome/browser/chrome_thread.h"
+#include "chrome/browser/download/download_file.h"
+#include "chrome/browser/download/download_manager.h"
+#include "chrome/browser/profile.h"
+#include "chrome/browser/tab_contents/tab_contents.h"
+#include "net/base/file_stream.h"
+
+DragDownloadFile::DragDownloadFile(
+    const FilePath& file_name_or_path,
+    linked_ptr<net::FileStream> file_stream,
+    const GURL& url,
+    const GURL& referrer,
+    const std::string& referrer_encoding,
+    TabContents* tab_contents)
+    : file_stream_(file_stream),
+      url_(url),
+      referrer_(referrer),
+      referrer_encoding_(referrer_encoding),
+      tab_contents_(tab_contents),
+      drag_message_loop_(MessageLoop::current()),
+      is_started_(false),
+      is_successful_(false),
+      download_manager_(NULL),
+      download_item_observer_added_(false) {
+#if defined(OS_WIN)
+  DCHECK(!file_name_or_path.empty() && !file_stream.get());
+  file_name_ = file_name_or_path;
+#elif defined(OS_MACOSX)
+  DCHECK(!file_name_or_path.empty() && file_stream.get());
+  file_path_ = file_name_or_path;
+#endif
+}
+
+DragDownloadFile::~DragDownloadFile() {
+  AssertCurrentlyOnDragThread();
+
+  // Since the target application can still hold and use the dragged file,
+  // we do not know the time that it can be safely deleted. To solve this
+  // problem, we schedule it to be removed after the system is restarted.
+#if defined(OS_WIN)
+  if (!temp_dir_path_.empty()) {
+    if (!file_path_.empty())
+      file_util::DeleteAfterReboot(file_path_);
+    file_util::DeleteAfterReboot(temp_dir_path_);
+  }
+#endif
+
+  if (download_manager_)
+    download_manager_->RemoveObserver(this);
+}
+
+bool DragDownloadFile::Start(DownloadFileObserver* observer) {
+  AssertCurrentlyOnDragThread();
+
+  if (is_started_)
+    return true;
+  is_started_ = true;
+
+  DCHECK(!observer_.get());
+  observer_ = observer;
+
+  if (!file_stream_.get()) {
+    // Create a temporary directory to save the temporary download file. We do
+    // not want to use the default download directory since we do not want the
+    // twisted file name shown in the download shelf if the file with the same
+    // name already exists.
+    if (!file_util::CreateNewTempDirectory(FILE_PATH_LITERAL("chrome"),
+                                           &temp_dir_path_))
+      return false;
+
+    file_path_ = temp_dir_path_.Append(file_name_);
+  }
+
+  InitiateDownload();
+
+  // On Windows, we need to wait till the download file is completed.
+#if defined(OS_WIN)
+  StartNestedMessageLoop();
+#endif
+
+  return is_successful_;
+}
+
+void DragDownloadFile::Stop() {
+}
+
+void DragDownloadFile::InitiateDownload() {
+#if defined(OS_WIN)
+  // DownloadManager could only be invoked from the UI thread.
+  if (!ChromeThread::CurrentlyOn(ChromeThread::UI)) {
+    ChromeThread::PostTask(
+        ChromeThread::UI, FROM_HERE,
+        NewRunnableMethod(this,
+                          &DragDownloadFile::InitiateDownload));
+    return;
+  }
+#endif
+
+  download_manager_ = tab_contents_->profile()->GetDownloadManager();
+  download_manager_->AddObserver(this);
+
+  DownloadSaveInfo save_info;
+  save_info.file_path = file_path_;
+  save_info.file_stream = file_stream_;
+  download_manager_->DownloadUrlToFile(url_,
+                                       referrer_,
+                                       referrer_encoding_,
+                                       save_info,
+                                       tab_contents_);
+}
+
+void DragDownloadFile::DownloadCompleted(bool is_successful) {
+#if defined(OS_WIN)
+  // If not in drag-and-drop thread, defer the running to it.
+  if (drag_message_loop_ != MessageLoop::current()) {
+    drag_message_loop_->PostTask(
+        FROM_HERE,
+        NewRunnableMethod(this,
+                          &DragDownloadFile::DownloadCompleted,
+                          is_successful));
+    return;
+  }
+#endif
+
+  is_successful_ = is_successful;
+
+  // Call the observer.
+  DCHECK(observer_);
+  if (is_successful)
+    observer_->OnDownloadCompleted(file_path_);
+  else
+    observer_->OnDownloadAborted();
+
+  // Release the observer since we do not need it any more.
+  observer_ = NULL;
+
+  // On Windows, we need to stop the waiting.
+#if defined(OS_WIN)
+  QuitNestedMessageLoop();
+#endif
+}
+
+void DragDownloadFile::ModelChanged() {
+  AssertCurrentlyOnUIThread();
+
+  download_manager_->GetTemporaryDownloads(this, file_path_.DirName());
+}
+
+void DragDownloadFile::SetDownloads(std::vector<DownloadItem*>& downloads) {
+  AssertCurrentlyOnUIThread();
+
+  std::vector<DownloadItem*>::const_iterator it = downloads.begin();
+  for (; it != downloads.end(); ++it) {
+    if (!download_item_observer_added_ && (*it)->url() == url_) {
+      download_item_observer_added_ = true;
+      (*it)->AddObserver(this);
+    }
+  }
+}
+
+void DragDownloadFile::OnDownloadUpdated(DownloadItem* download) {
+  AssertCurrentlyOnUIThread();
+
+  if (download->state() == DownloadItem::CANCELLED) {
+    download->RemoveObserver(this);
+    download_manager_->RemoveObserver(this);
+
+    DownloadCompleted(false);
+  }
+}
+
+void DragDownloadFile::OnDownloadFileCompleted(DownloadItem* download) {
+  AssertCurrentlyOnUIThread();
+  DCHECK(download->state() == DownloadItem::COMPLETE);
+
+  download->RemoveObserver(this);
+  download_manager_->RemoveObserver(this);
+
+  DownloadCompleted(true);
+}
+
+void DragDownloadFile::AssertCurrentlyOnDragThread() {
+  // Only do the check on Windows where two threads are involved.
+#if defined(OS_WIN)
+  DCHECK(drag_message_loop_ == MessageLoop::current());
+#endif
+}
+
+void DragDownloadFile::AssertCurrentlyOnUIThread() {
+  // Only do the check on Windows where two threads are involved.
+#if defined(OS_WIN)
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
+#endif
+}
+
+#if defined(OS_WIN)
+void DragDownloadFile::StartNestedMessageLoop() {
+  AssertCurrentlyOnDragThread();
+
+  bool old_state = MessageLoop::current()->NestableTasksAllowed();
+  MessageLoop::current()->SetNestableTasksAllowed(true);
+  is_running_nested_message_loop_ = true;
+  MessageLoop::current()->Run();
+  MessageLoop::current()->SetNestableTasksAllowed(old_state);
+}
+
+void DragDownloadFile::QuitNestedMessageLoop() {
+  AssertCurrentlyOnDragThread();
+
+  if (is_running_nested_message_loop_) {
+    is_running_nested_message_loop_ = false;
+    MessageLoop::current()->Quit();
+  }
+}
+#endif
diff --git a/chrome/browser/download/drag_download_file.h b/chrome/browser/download/drag_download_file.h
new file mode 100644
index 0000000..31064ec
--- /dev/null
+++ b/chrome/browser/download/drag_download_file.h
@@ -0,0 +1,112 @@
+// Copyright (c) 2009-2010 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_DRAG_DOWNLOAD_FILE_H_
+#define CHROME_BROWSER_DOWNLOAD_DRAG_DOWNLOAD_FILE_H_
+
+#include "app/download_file_interface.h"
+#include "base/file_path.h"
+#include "base/linked_ptr.h"
+#include "chrome/browser/download/download_file.h"
+#include "chrome/browser/download/download_manager.h"
+#include "googleurl/src/gurl.h"
+
+class TabContents;
+
+namespace net {
+class FileSteram;
+}
+
+class DragDownloadFile : public DownloadFileProvider,
+                         public DownloadManager::Observer,
+                         public DownloadItem::Observer {
+ public:
+  // On Windows, we need to download into a temporary file. Two threads are
+  // involved: background drag-and-drop thread and UI thread.
+  // The first parameter file_name_or_path should contain file name while the
+  // second parameter file_stream should be NULL.
+  //
+  // On MacOSX, we need to download into a file stream that has already been
+  // created. Only UI thread is involved.
+  // The file path and file stream should be provided as the first two
+  // parameters.
+  DragDownloadFile(const FilePath& file_name_or_path,
+                   linked_ptr<net::FileStream> file_stream,
+                   const GURL& url,
+                   const GURL& referrer,
+                   const std::string& referrer_encoding,
+                   TabContents* tab_contents);
+
+  // DownloadFileProvider methods.
+  // Called on drag-and-drop thread (Windows).
+  // Called on UI thread (MacOSX).
+  virtual bool Start(DownloadFileObserver* observer);
+  virtual void Stop();
+#if defined(OS_WIN)
+  virtual IStream* GetStream() { return NULL; }
+#endif
+
+  // DownloadManager::Observer methods.
+  // Called on UI thread.
+  virtual void ModelChanged();
+  virtual void SetDownloads(std::vector<DownloadItem*>& downloads);
+
+  // DownloadItem::Observer methods.
+  // Called on UI thread.
+  virtual void OnDownloadUpdated(DownloadItem* download);
+  virtual void OnDownloadFileCompleted(DownloadItem* download);
+  virtual void OnDownloadOpened(DownloadItem* download) { }
+
+ private:
+  // Called on drag-and-drop thread (Windows).
+  // Called on UI thread (Windows).
+  virtual ~DragDownloadFile();
+
+  // Called on drag-and-drop thread (Windows only).
+#if defined(OS_WIN)
+  void StartNestedMessageLoop();
+  void QuitNestedMessageLoop();
+#endif
+
+  // Called on either drag-and-drop thread or UI thread (Windows).
+  // Called on UI thread (MacOSX).
+  void InitiateDownload();
+  void DownloadCompleted(bool is_successful);
+
+  // Helper methods to make sure we're in the correct thread.
+  void AssertCurrentlyOnDragThread();
+  void AssertCurrentlyOnUIThread();
+
+  // Initialized on drag-and-drop thread. Accessed on either thread after that
+  // (Windows).
+  // Accessed on UI thread (MacOSX).
+  FilePath file_path_;
+  FilePath file_name_;
+  linked_ptr<net::FileStream> file_stream_;
+  GURL url_;
+  GURL referrer_;
+  std::string referrer_encoding_;
+  TabContents* tab_contents_;
+  MessageLoop* drag_message_loop_;
+  FilePath temp_dir_path_;
+
+  // Accessed on drag-and-drop thread (Windows).
+  // Accessed on UI thread (MacOSX).
+  bool is_started_;
+  bool is_successful_;
+  scoped_refptr<DownloadFileObserver> observer_;
+
+  // Accessed on drag-and-drop thread (Windows only).
+#if defined(OS_WIN)
+  bool is_running_nested_message_loop_;
+#endif
+
+  // Access on UI thread.
+  DownloadManager* download_manager_;
+  bool download_item_observer_added_;
+
+  DISALLOW_COPY_AND_ASSIGN(DragDownloadFile);
+};
+
+#endif  // CHROME_BROWSER_DOWNLOAD_DRAG_DOWNLOAD_FILE_H_
diff --git a/chrome/browser/download/drag_download_file_win.cc b/chrome/browser/download/drag_download_file_win.cc
deleted file mode 100644
index 77a9112..0000000
--- a/chrome/browser/download/drag_download_file_win.cc
+++ /dev/null
@@ -1,217 +0,0 @@
-// Copyright (c) 2009 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/drag_download_file_win.h"
-
-#include "base/file_util.h"
-#include "base/message_loop.h"
-#include "chrome/browser/chrome_thread.h"
-#include "chrome/browser/download/download_manager.h"
-#include "chrome/browser/profile.h"
-#include "chrome/browser/tab_contents/tab_contents.h"
-
-DragDownloadFile::DragDownloadFile(
-    const GURL& url,
-    const GURL& referrer,
-    const std::string& referrer_encoding,
-    TabContents* tab_contents)
-    : url_(url),
-      referrer_(referrer),
-      referrer_encoding_(referrer_encoding),
-      tab_contents_(tab_contents),
-      drag_message_loop_(MessageLoop::current()),
-      is_started_(false),
-      is_running_nested_message_loop_(false),
-      initiate_download_result_(false),
-      format_(0),
-      download_manager_(NULL),
-      download_item_observer_added_(false) {
-}
-
-DragDownloadFile::~DragDownloadFile() {
-  DCHECK(drag_message_loop_ == MessageLoop::current());
-
-  // Since the target application can still hold and use the dragged file,
-  // we do not know the time that it can be safely deleted. To solve this
-  // problem, we schedule it to be removed after the system is restarted.
-#if defined(OS_WIN)
-  if (!dir_path_.empty()) {
-    if (!file_path_.empty())
-      file_util::DeleteAfterReboot(file_path_);
-    file_util::DeleteAfterReboot(dir_path_);
-  }
-#endif
-
-  if (download_manager_)
-    download_manager_->RemoveObserver(this);
-}
-
-bool DragDownloadFile::Start(OSExchangeData::DownloadFileObserver* observer,
-                             int format) {
-  DCHECK(drag_message_loop_ == MessageLoop::current());
-
-  if (is_started_)
-    return true;
-  is_started_ = true;
-
-  DCHECK(!observer_.get());
-  observer_ = observer;
-  format_ = format;
-
-  if (!InitiateDownload())
-    return false;
-
-  // Wait till the download is fully initiated.
-  StartNestedMessageLoop();
-
-  return initiate_download_result_;
-}
-
-void DragDownloadFile::Stop() {
-}
-
-bool DragDownloadFile::InitiateDownload() {
-  DCHECK(drag_message_loop_ == MessageLoop::current());
-
-  // Create a temporary directory to save the temporary download file. We do
-  // not want to use the default download directory since we do not want the
-  // twisted file name shown in the download shelf if the file with the same
-  // name already exists.
-  if (!file_util::CreateNewTempDirectory(FILE_PATH_LITERAL("chrome"),
-                                         &dir_path_))
-    return false;
-
-  // DownloadManager could only be invoked from the UI thread.
-  ChromeThread::PostTask(
-      ChromeThread::UI, FROM_HERE,
-      NewRunnableMethod(this,
-                        &DragDownloadFile::OnInitiateDownload,
-                        dir_path_));
-
-  return true;
-}
-
-void DragDownloadFile::OnInitiateDownload(const FilePath& dir_path) {
-  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
-
-  download_manager_ = tab_contents_->profile()->GetDownloadManager();
-  download_manager_->AddObserver(this);
-
-  // Start the download.
-  download_manager_->DownloadUrlToFile(url_,
-                                       referrer_,
-                                       referrer_encoding_,
-                                       dir_path,
-                                       tab_contents_);
-}
-
-void DragDownloadFile::InitiateDownloadSucceeded(
-    const std::vector<OSExchangeData::DownloadFileInfo*>& downloads) {
-  DCHECK(drag_message_loop_ == MessageLoop::current());
-
-  // Notify the drag-and-drop observer about the file info.
-  DCHECK(observer_);
-  observer_->OnDataReady(format_, downloads);
-
-  InitiateDownloadCompleted(true);
-}
-
-void DragDownloadFile::InitiateDownloadFailed() {
-  DCHECK(drag_message_loop_ == MessageLoop::current());
-
-  InitiateDownloadCompleted(false);
-}
-
-void DragDownloadFile::InitiateDownloadCompleted(bool result) {
-  DCHECK(drag_message_loop_ == MessageLoop::current());
-
-  // Release the observer since we do not need it any more.
-  observer_ = NULL;
-
-  initiate_download_result_ = result;
-  QuitNestedMessageLoopIfNeeded();
-}
-
-void DragDownloadFile::StartNestedMessageLoop() {
-  DCHECK(drag_message_loop_ == MessageLoop::current());
-
-  bool old_state = MessageLoop::current()->NestableTasksAllowed();
-  MessageLoop::current()->SetNestableTasksAllowed(true);
-  is_running_nested_message_loop_ = true;
-  MessageLoop::current()->Run();
-  MessageLoop::current()->SetNestableTasksAllowed(old_state);
-}
-
-void DragDownloadFile::QuitNestedMessageLoopIfNeeded() {
-  DCHECK(drag_message_loop_ == MessageLoop::current());
-
-  if (is_running_nested_message_loop_) {
-    is_running_nested_message_loop_ = false;
-    MessageLoop::current()->Quit();
-  }
-}
-
-void DragDownloadFile::ModelChanged() {
-  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
-
-  download_manager_->GetTemporaryDownloads(this, dir_path_);
-}
-
-void DragDownloadFile::SetDownloads(std::vector<DownloadItem*>& downloads) {
-  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
-
-  std::vector<DownloadItem*>::const_iterator it = downloads.begin();
-  for (; it != downloads.end(); ++it) {
-    if (!download_item_observer_added_ && (*it)->url() == url_) {
-      download_item_observer_added_ = true;
-      (*it)->AddObserver(this);
-    }
-  }
-}
-
-void DragDownloadFile::OnDownloadUpdated(DownloadItem* download) {
-  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
-
-  if (download->state() == DownloadItem::CANCELLED) {
-    download->RemoveObserver(this);
-    download_manager_->RemoveObserver(this);
-
-    drag_message_loop_->PostTask(
-        FROM_HERE,
-        NewRunnableMethod(this,
-                          &DragDownloadFile::DownloadCancelled));
-  }
-}
-
-void DragDownloadFile::OnDownloadFileCompleted(DownloadItem* download) {
-  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
-  DCHECK(download->state() == DownloadItem::COMPLETE);
-
-  download->RemoveObserver(this);
-  download_manager_->RemoveObserver(this);
-
-  drag_message_loop_->PostTask(
-      FROM_HERE,
-      NewRunnableMethod(this,
-                        &DragDownloadFile::DownloadCompleted,
-                        download->full_path()));
-}
-
-void DragDownloadFile::DownloadCancelled() {
-  DCHECK(drag_message_loop_ == MessageLoop::current());
-
-  InitiateDownloadFailed();
-}
-
-void DragDownloadFile::DownloadCompleted(const FilePath& file_path) {
-  DCHECK(drag_message_loop_ == MessageLoop::current());
-
-  file_path_ = file_path;
-
-  // The download has been successfully initiated.
-  std::vector<OSExchangeData::DownloadFileInfo*> downloads;
-  downloads.push_back(
-      new OSExchangeData::DownloadFileInfo(file_path, 0, NULL));
-  InitiateDownloadSucceeded(downloads);
-}
diff --git a/chrome/browser/download/drag_download_file_win.h b/chrome/browser/download/drag_download_file_win.h
deleted file mode 100644
index a1ef5ed..0000000
--- a/chrome/browser/download/drag_download_file_win.h
+++ /dev/null
@@ -1,84 +0,0 @@
-// Copyright (c) 2009 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_DRAG_DOWNLOAD_FILE_WIN_H_
-#define CHROME_BROWSER_DOWNLOAD_DRAG_DOWNLOAD_FILE_WIN_H_
-
-#include "app/os_exchange_data.h"
-#include "base/file_path.h"
-#include "chrome/browser/download/download_manager.h"
-#include "googleurl/src/gurl.h"
-
-class TabContents;
-
-class DragDownloadFile : public OSExchangeData::DownloadFileProvider,
-                         public DownloadManager::Observer,
-                         public DownloadItem::Observer {
- public:
-  DragDownloadFile(const GURL& url,
-                   const GURL& referrer,
-                   const std::string& referrer_encoding,
-                   TabContents* tab_contents);
-
-  // OSExchangeData::DownloadFileProvider methods.
-  // Called on drag-and-drop thread.
-  virtual bool Start(OSExchangeData::DownloadFileObserver* observer,
-                     int format);
-  virtual void Stop();
-
-  // DownloadManager::Observer methods.
-  // Called on UI thread.
-  virtual void ModelChanged();
-  virtual void SetDownloads(std::vector<DownloadItem*>& downloads);
-
-  // DownloadItem::Observer methods.
-  // Called on UI thread.
-  virtual void OnDownloadUpdated(DownloadItem* download);
-  virtual void OnDownloadFileCompleted(DownloadItem* download);
-  virtual void OnDownloadOpened(DownloadItem* download) { }
-
- private:
-  // Called on drag-and-drop thread.
-  virtual ~DragDownloadFile();
-
-  bool InitiateDownload();
-  void InitiateDownloadSucceeded(
-      const std::vector<OSExchangeData::DownloadFileInfo*>& downloads);
-  void InitiateDownloadFailed();
-  void InitiateDownloadCompleted(bool result);
-
-  void DownloadCancelled();
-  void DownloadCompleted(const FilePath& file_path);
-
-  void StartNestedMessageLoop();
-  void QuitNestedMessageLoopIfNeeded();
-
-  // Called on UI thread.
-  void OnInitiateDownload(const FilePath& dir_path);
-  void CheckDownloadStatus(DownloadItem* download);
-
-  // Initialized on drag-and-drop thread. Can be accessed on either thread.
-  GURL url_;
-  GURL referrer_;
-  std::string referrer_encoding_;
-  TabContents* tab_contents_;
-  MessageLoop* drag_message_loop_;
-
-  // Accessed on drag-and-drop thread.
-  bool is_started_;
-  bool is_running_nested_message_loop_;
-  bool initiate_download_result_;
-  scoped_refptr<OSExchangeData::DownloadFileObserver> observer_;
-  int format_;
-  FilePath dir_path_;
-  FilePath file_path_;
-
-  // Access on UI thread.
-  DownloadManager* download_manager_;
-  bool download_item_observer_added_;
-
-  DISALLOW_COPY_AND_ASSIGN(DragDownloadFile);
-};
-
-#endif  // CHROME_BROWSER_DOWNLOAD_DRAG_DOWNLOAD_FILE_WIN_H_
diff --git a/chrome/browser/download/drag_download_util.cc b/chrome/browser/download/drag_download_util.cc
new file mode 100644
index 0000000..ed34e70
--- /dev/null
+++ b/chrome/browser/download/drag_download_util.cc
@@ -0,0 +1,48 @@
+// Copyright (c) 2010 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/drag_download_util.h"
+
+#include "base/string_util.h"
+#include "base/utf_string_conversions.h"
+#include "googleurl/src/gurl.h"
+
+namespace drag_download_util {
+
+bool ParseDownloadMetadata(const string16& metadata,
+                           string16* mime_type,
+                           FilePath* file_name,
+                           GURL* url) {
+  const char16 separator = L':';
+
+  size_t mime_type_end_pos = metadata.find(separator);
+  if (mime_type_end_pos == string16::npos)
+    return false;
+
+  size_t file_name_end_pos = metadata.find(separator, mime_type_end_pos + 1);
+  if (file_name_end_pos == string16::npos)
+    return false;
+
+  GURL parsed_url = GURL(metadata.substr(file_name_end_pos + 1));
+  if (!parsed_url.is_valid())
+    return false;
+
+  if (mime_type)
+    *mime_type = metadata.substr(0, mime_type_end_pos);
+  if (file_name) {
+    string16 file_name_str = metadata.substr(
+        mime_type_end_pos + 1, file_name_end_pos - mime_type_end_pos  - 1);
+#if defined(OS_WIN)
+    *file_name = FilePath(file_name_str);
+#else
+    *file_name = FilePath(UTF16ToUTF8(file_name_str));
+#endif
+  }
+  if (url)
+    *url = parsed_url;
+
+  return true;
+}
+
+}  // namespace drag_download_util
diff --git a/chrome/browser/download/drag_download_util.h b/chrome/browser/download/drag_download_util.h
new file mode 100644
index 0000000..7f2a853
--- /dev/null
+++ b/chrome/browser/download/drag_download_util.h
@@ -0,0 +1,29 @@
+// Copyright (c) 2010 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_DRAG_DOWNLOAD_UTIL_H_
+#define CHROME_BROWSER_DOWNLOAD_DRAG_DOWNLOAD_UTIL_H_
+
+#include "base/basictypes.h"
+#include "base/file_path.h"
+
+class GURL;
+
+namespace drag_download_util {
+
+// Parse the download metadata set in DataTransfer.setData. The metadata
+// consists of a set of the following values separated by ":"
+// * MIME type
+// * File name
+// * URL
+// For example, we can have
+//   text/plain:example.txt:http://example.com/example.txt
+bool ParseDownloadMetadata(const string16& metadata,
+                           string16* mime_type,
+                           FilePath* file_name,
+                           GURL* url);
+
+}  // namespace drag_download_util
+
+#endif  // CHROME_BROWSER_DOWNLOAD_DRAG_DOWNLOAD_UTIL_H_
diff --git a/chrome/browser/history/download_types.h b/chrome/browser/history/download_types.h
index 7025b1d..50c7e26 100644
--- a/chrome/browser/history/download_types.h
+++ b/chrome/browser/history/download_types.h
@@ -12,6 +12,7 @@
 #include "base/basictypes.h"
 #include "base/file_path.h"
 #include "base/time.h"
+#include "chrome/browser/download/download_file.h"
 #include "googleurl/src/gurl.h"
 
 // Used for informing the download database of a new download, where we don't
@@ -87,8 +88,8 @@ struct DownloadCreateInfo {
   // The charset of the referring page where the download request comes from.
   // It's used to construct a suggested filename.
   std::string referrer_charset;
-  // The file path to save to.
-  FilePath save_file_path;
+  // The download file save info.
+  DownloadSaveInfo save_info;
 };
 
 #endif  // CHROME_BROWSER_HISTORY_DOWNLOAD_TYPES_H_
diff --git a/chrome/browser/renderer_host/download_resource_handler.cc b/chrome/browser/renderer_host/download_resource_handler.cc
index e414587..1bbb757 100644
--- a/chrome/browser/renderer_host/download_resource_handler.cc
+++ b/chrome/browser/renderer_host/download_resource_handler.cc
@@ -13,15 +13,16 @@
 #include "net/base/io_buffer.h"
 #include "net/url_request/url_request_context.h"
 
-DownloadResourceHandler::DownloadResourceHandler(ResourceDispatcherHost* rdh,
-                                                 int render_process_host_id,
-                                                 int render_view_id,
-                                                 int request_id,
-                                                 const GURL& url,
-                                                 DownloadFileManager* manager,
-                                                 URLRequest* request,
-                                                 bool save_as,
-                                                 const FilePath& save_file_path)
+DownloadResourceHandler::DownloadResourceHandler(
+    ResourceDispatcherHost* rdh,
+    int render_process_host_id,
+    int render_view_id,
+    int request_id,
+    const GURL& url,
+    DownloadFileManager* manager,
+    URLRequest* request,
+    bool save_as,
+    const DownloadSaveInfo& save_info)
     : download_id_(-1),
       global_id_(render_process_host_id, request_id),
       render_view_id_(render_view_id),
@@ -30,7 +31,7 @@ DownloadResourceHandler::DownloadResourceHandler(ResourceDispatcherHost* rdh,
       download_manager_(manager),
       request_(request),
       save_as_(save_as),
-      save_file_path_(save_file_path),
+      save_info_(save_info),
       buffer_(new DownloadBuffer),
       rdh_(rdh),
       is_paused_(false) {
@@ -69,10 +70,10 @@ bool DownloadResourceHandler::OnResponseStarted(int request_id,
   info->request_id = global_id_.request_id;
   info->content_disposition = content_disposition_;
   info->mime_type = response->response_head.mime_type;
-  info->save_as = save_as_ && save_file_path_.empty();
+  info->save_as = save_as_ && save_info_.file_path.empty();
   info->is_dangerous = false;
   info->referrer_charset = request_->context()->referrer_charset();
-  info->save_file_path = save_file_path_;
+  info->save_info = save_info_;
   ChromeThread::PostTask(
       ChromeThread::FILE, FROM_HERE,
       NewRunnableMethod(
diff --git a/chrome/browser/renderer_host/download_resource_handler.h b/chrome/browser/renderer_host/download_resource_handler.h
index 59b4cb4..bb8d9cd 100644
--- a/chrome/browser/renderer_host/download_resource_handler.h
+++ b/chrome/browser/renderer_host/download_resource_handler.h
@@ -9,6 +9,7 @@
 
 #include "base/file_path.h"
 #include "base/timer.h"
+#include "chrome/browser/download/download_file.h"
 #include "chrome/browser/renderer_host/global_request_id.h"
 #include "chrome/browser/renderer_host/resource_handler.h"
 
@@ -28,7 +29,7 @@ class DownloadResourceHandler : public ResourceHandler {
                           DownloadFileManager* manager,
                           URLRequest* request,
                           bool save_as,
-                          const FilePath& save_file_path);
+                          const DownloadSaveInfo& save_info);
 
   // Not needed, as this event handler ought to be the final resource.
   bool OnRequestRedirected(int request_id, const GURL& url,
@@ -72,7 +73,7 @@ class DownloadResourceHandler : public ResourceHandler {
   DownloadFileManager* download_manager_;
   URLRequest* request_;
   bool save_as_;  // Request was initiated via "Save As" by the user.
-  FilePath save_file_path_;
+  DownloadSaveInfo save_info_;
   DownloadBuffer* buffer_;
   ResourceDispatcherHost* rdh_;
   bool is_paused_;
diff --git a/chrome/browser/renderer_host/download_throttling_resource_handler.cc b/chrome/browser/renderer_host/download_throttling_resource_handler.cc
index 4b02880..87314dc 100644
--- a/chrome/browser/renderer_host/download_throttling_resource_handler.cc
+++ b/chrome/browser/renderer_host/download_throttling_resource_handler.cc
@@ -130,7 +130,6 @@ void DownloadThrottlingResourceHandler::CancelDownload() {
 
 void DownloadThrottlingResourceHandler::ContinueDownload() {
   DCHECK(!download_handler_.get());
-  FilePath save_file_path;
   download_handler_ =
       new DownloadResourceHandler(host_,
                                   render_process_host_id_,
@@ -140,7 +139,7 @@ void DownloadThrottlingResourceHandler::ContinueDownload() {
                                   host_->download_file_manager(),
                                   request_,
                                   false,
-                                  save_file_path);
+                                  DownloadSaveInfo());
   if (response_.get())
     download_handler_->OnResponseStarted(request_id_, response_.get());
 
diff --git a/chrome/browser/renderer_host/resource_dispatcher_host.cc b/chrome/browser/renderer_host/resource_dispatcher_host.cc
index 971888c..b92c6a9 100644
--- a/chrome/browser/renderer_host/resource_dispatcher_host.cc
+++ b/chrome/browser/renderer_host/resource_dispatcher_host.cc
@@ -560,12 +560,13 @@ void ResourceDispatcherHost::OnClosePageACK(
 }
 
 // We are explicitly forcing the download of 'url'.
-void ResourceDispatcherHost::BeginDownload(const GURL& url,
-                                           const GURL& referrer,
-                                           const FilePath& save_file_path,
-                                           int child_id,
-                                           int route_id,
-                                           URLRequestContext* request_context) {
+void ResourceDispatcherHost::BeginDownload(
+    const GURL& url,
+    const GURL& referrer,
+    const DownloadSaveInfo& save_info,
+    int child_id,
+    int route_id,
+    URLRequestContext* request_context) {
   if (is_shutdown_)
     return;
 
@@ -593,7 +594,7 @@ void ResourceDispatcherHost::BeginDownload(const GURL& url,
                                   download_file_manager_.get(),
                                   request,
                                   true,
-                                  save_file_path);
+                                  save_info);
 
 
   if (safe_browsing_->enabled() && safe_browsing_->CanCheckUrl(url)) {
diff --git a/chrome/browser/renderer_host/resource_dispatcher_host.h b/chrome/browser/renderer_host/resource_dispatcher_host.h
index 4e10dae..c410f3a 100644
--- a/chrome/browser/renderer_host/resource_dispatcher_host.h
+++ b/chrome/browser/renderer_host/resource_dispatcher_host.h
@@ -42,6 +42,7 @@ class SSLClientAuthHandler;
 class UserScriptListener;
 class URLRequestContext;
 class WebKitThread;
+struct DownloadSaveInfo;
 struct GlobalRequestID;
 struct ViewHostMsg_Resource_Request;
 struct ViewMsg_ClosePage_Params;
@@ -107,7 +108,7 @@ class ResourceDispatcherHost : public URLRequest::Delegate {
   // request from the renderer or another child process).
   void BeginDownload(const GURL& url,
                      const GURL& referrer,
-                     const FilePath& save_file_path,
+                     const DownloadSaveInfo& save_info,
                      int process_unique_id,
                      int route_id,
                      URLRequestContext* request_context);
diff --git a/chrome/browser/renderer_host/resource_message_filter.cc b/chrome/browser/renderer_host/resource_message_filter.cc
index 2c04259..ae3ddd4 100644
--- a/chrome/browser/renderer_host/resource_message_filter.cc
+++ b/chrome/browser/renderer_host/resource_message_filter.cc
@@ -15,6 +15,7 @@
 #include "chrome/browser/child_process_security_policy.h"
 #include "chrome/browser/chrome_plugin_browsing_context.h"
 #include "chrome/browser/chrome_thread.h"
+#include "chrome/browser/download/download_file.h"
 #include "chrome/browser/extensions/extension_file_util.h"
 #include "chrome/browser/extensions/extension_message_service.h"
 #include "chrome/browser/host_zoom_map.h"
@@ -778,10 +779,9 @@ void ResourceMessageFilter::OnDownloadUrl(const IPC::Message& message,
                                           const GURL& url,
                                           const GURL& referrer) {
   URLRequestContext* context = request_context_->GetURLRequestContext();
-  FilePath save_file_path;
   resource_dispatcher_host_->BeginDownload(url,
                                            referrer,
-                                           save_file_path,
+                                           DownloadSaveInfo(),
                                            id(),
                                            message.routing_id(),
                                            context);
diff --git a/chrome/browser/views/tab_contents/tab_contents_drag_win.cc b/chrome/browser/views/tab_contents/tab_contents_drag_win.cc
index 013dd40..59ddfd3 100644
--- a/chrome/browser/views/tab_contents/tab_contents_drag_win.cc
+++ b/chrome/browser/views/tab_contents/tab_contents_drag_win.cc
@@ -10,10 +10,12 @@
 #include "base/message_loop.h"
 #include "base/task.h"
 #include "base/thread.h"
+#include "base/utf_string_conversions.h"
 #include "base/win_util.h"
 #include "chrome/browser/bookmarks/bookmark_drag_data.h"
 #include "chrome/browser/chrome_thread.h"
-#include "chrome/browser/download/drag_download_file_win.h"
+#include "chrome/browser/download/drag_download_file.h"
+#include "chrome/browser/download/drag_download_util.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/tab_contents/tab_contents.h"
 #include "chrome/browser/tab_contents/web_drag_source_win.h"
@@ -112,7 +114,7 @@ void TabContentsDragWin::StartDragging(const WebDropData& drop_data,
   const std::string& page_encoding = view_->tab_contents()->encoding();
 
   // If it is not drag-out, do the drag-and-drop in the current UI thread.
-  if (!drop_data.download_url.is_valid()) {
+  if (drop_data.download_metadata.empty()) {
     DoDragging(drop_data, ops, page_url, page_encoding);
     EndDragging(false);
     return;
@@ -171,17 +173,38 @@ void TabContentsDragWin::PrepareDragForDownload(
     OSExchangeData* data,
     const GURL& page_url,
     const std::string& page_encoding) {
+  // Parse the download metadata.
+  string16 mime_type;
+  FilePath file_name;
+  GURL download_url;
+  if (!drag_download_util::ParseDownloadMetadata(drop_data.download_metadata,
+                                                 &mime_type,
+                                                 &file_name,
+                                                 &download_url))
+    return;
+
+  // Generate the download filename.
+  std::string content_disposition =
+      "attachment; filename=" + UTF16ToUTF8(file_name.value());
+  FilePath generated_file_name;
+  DownloadManager::GenerateFileName(download_url,
+                                    content_disposition,
+                                    std::string(),
+                                    UTF16ToUTF8(mime_type),
+                                    &generated_file_name);
+
   // Provide the data as file (CF_HDROP). A temporary download file with the
   // Zone.Identifier ADS (Alternate Data Stream) attached will be created.
+  linked_ptr<net::FileStream> empty_file_stream;
   scoped_refptr<DragDownloadFile> download_file =
-      new DragDownloadFile(drop_data.download_url,
+      new DragDownloadFile(generated_file_name,
+                           empty_file_stream,
+                           download_url,
                            page_url,
                            page_encoding,
                            view_->tab_contents());
-  OSExchangeData::DownloadFileInfo* file_download =
-      new OSExchangeData::DownloadFileInfo(FilePath(),
-                                           0,
-                                           download_file.get());
+  OSExchangeData::DownloadFileInfo file_download(FilePath(),
+                                                 download_file.get());
   data->SetDownloadFileInfo(file_download);
 
   // Enable asynchronous operation.
@@ -238,7 +261,7 @@ void TabContentsDragWin::DoDragging(const WebDropData& drop_data,
 
   // TODO(tc): Generate an appropriate drag image.
 
-  if (drop_data.download_url.is_valid()) {
+  if (!drop_data.download_metadata.empty()) {
     PrepareDragForDownload(drop_data, &data, page_url, page_encoding);
 
     // Set the observer.
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 94a563e..f149430 100755
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -728,8 +728,10 @@
         'browser/download/download_started_animation.h',
         'browser/download/download_util.cc',
         'browser/download/download_util.h',
-        'browser/download/drag_download_file_win.cc',
-        'browser/download/drag_download_file_win.h',
+        'browser/download/drag_download_file.cc',
+        'browser/download/drag_download_file.h',
+        'browser/download/drag_download_util.cc',
+        'browser/download/drag_download_util.h',
         'browser/download/save_file.cc',
         'browser/download/save_file.h',
         'browser/download/save_file_manager.cc',
diff --git a/chrome/common/render_messages.h b/chrome/common/render_messages.h
index d985d2d..8c2eaed 100644
--- a/chrome/common/render_messages.h
+++ b/chrome/common/render_messages.h
@@ -1790,7 +1790,7 @@ struct ParamTraits<WebDropData> {
     WriteParam(m, p.identity);
     WriteParam(m, p.url);
     WriteParam(m, p.url_title);
-    WriteParam(m, p.download_url);
+    WriteParam(m, p.download_metadata);
     WriteParam(m, p.file_extension);
     WriteParam(m, p.filenames);
     WriteParam(m, p.plain_text);
@@ -1804,7 +1804,7 @@ struct ParamTraits<WebDropData> {
       ReadParam(m, iter, &p->identity) &&
       ReadParam(m, iter, &p->url) &&
       ReadParam(m, iter, &p->url_title) &&
-      ReadParam(m, iter, &p->download_url) &&
+      ReadParam(m, iter, &p->download_metadata) &&
       ReadParam(m, iter, &p->file_extension) &&
       ReadParam(m, iter, &p->filenames) &&
       ReadParam(m, iter, &p->plain_text) &&
diff --git a/webkit/glue/webdropdata.cc b/webkit/glue/webdropdata.cc
index bf2de89..d46987a 100644
--- a/webkit/glue/webdropdata.cc
+++ b/webkit/glue/webdropdata.cc
@@ -19,7 +19,7 @@ WebDropData::WebDropData(const WebDragData& drag_data)
     : identity(0),
       url(drag_data.url()),
       url_title(drag_data.urlTitle()),
-      download_url(drag_data.downloadURL()),
+      download_metadata(drag_data.downloadMetadata()),
       file_extension(drag_data.fileExtension()),
       plain_text(drag_data.plainText()),
       text_html(drag_data.htmlText()),
diff --git a/webkit/glue/webdropdata.h b/webkit/glue/webdropdata.h
index 96edfea..8149d8e 100644
--- a/webkit/glue/webdropdata.h
+++ b/webkit/glue/webdropdata.h
@@ -39,7 +39,7 @@ struct WebDropData {
   string16 url_title;  // The title associated with |url|.
 
   // User is dragging a link out-of the webview.
-  GURL download_url;
+  string16 download_metadata;
 
   // File extension for dragging images from a webview to the desktop.
   string16 file_extension;