Implement IsMostRecentDownloadItemAtFilePath call

Implement IsMostRecentDownloadItemAtFilePath
for download_manager_delegate_qt. This is required for
CVE-2018-6033.

Change-Id: I9f48dfa159d684f0fda894e68b81ff622aceaae2
Reviewed-by: Allan Sandfeld Jensen <[email protected]>

Author: Michal Klocek

src/core/download_manager_delegate_qt.cpp

@@ -270,6 +270,26 @@ void DownloadManagerDelegateQt::ChooseSavePath(content::WebContents *web_content
                             m_weakPtrFactory.GetWeakPtr()));
 }
 
+bool DownloadManagerDelegateQt::IsMostRecentDownloadItemAtFilePath(content::DownloadItem *download)
+{
+    content::BrowserContext *context = download->GetBrowserContext();
+    std::vector<content::DownloadItem*> all_downloads;
+
+    content::DownloadManager* manager =
+            content::BrowserContext::GetDownloadManager(context);
+    if (manager)
+        manager->GetAllDownloads(&all_downloads);
+
+    for (const auto* item : all_downloads) {
+        if (item->GetGuid() == download->GetGuid() ||
+                item->GetTargetFilePath() != download->GetTargetFilePath())
+            continue;
+        if (item->GetState() == content::DownloadItem::IN_PROGRESS)
+            return false;
+    }
+    return true;
+}
+
 void DownloadManagerDelegateQt::savePackageDownloadCreated(content::DownloadItem *item)
 {
     OnDownloadUpdated(item);

src/core/download_manager_delegate_qt.h

@@ -81,6 +81,8 @@ class DownloadManagerDelegateQt
                         const base::FilePath::StringType &default_extension,
                         bool can_save_as_complete,
                         const content::SavePackagePathPickedCallback &callback) override;
+    bool IsMostRecentDownloadItemAtFilePath(content::DownloadItem* download) override;
+
 
     void cancelDownload(quint32 downloadId);