Adds a webstorePrivate method for silently installing extensions.

content/browser/download/download_manager.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/download/download_manager.h"
 
 #include <iterator>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 326 matching lines @@
 
   int32 download_id = download->id();
 
   // NOTE(ahendrickson) Eventually |active_downloads_| will replace
   // |in_progress_|, but we don't want to change the semantics yet.
   DCHECK(!ContainsKey(in_progress_, download_id));
   DCHECK(ContainsKey(downloads_, download));
   DCHECK(ContainsKey(active_downloads_, download_id));
 
   // Make sure the initial file name is set only once.
-  DCHECK(download->full_path().empty());
   download->OnPathDetermined(chosen_file);
 
   VLOG(20) << __FUNCTION__ << "()"
            << " download = " << download->DebugString(true);
 
   in_progress_[download_id] = download;
   UpdateDownloadProgress();  // Reflect entry into in_progress_.
 
   // Rename to intermediate name.
   FilePath download_path;
@@ skipping 716 matching lines @@
 void DownloadManager::MarkDownloadOpened(DownloadItem* download) {
   delegate_->UpdateItemInPersistentStore(download);
   int num_unopened = 0;
   for (DownloadMap::iterator it = history_downloads_.begin();
        it != history_downloads_.end(); ++it) {
     if (it->second->IsComplete() && !it->second->opened())
       ++num_unopened;
   }
   download_stats::RecordOpensOutstanding(num_unopened);
 }