[Downloads] Allow acquiring dangerous download file.

content/browser/download/download_item_impl.cc

Index: content/browser/download/download_item_impl.cc
diff --git a/content/browser/download/download_item_impl.cc b/content/browser/download/download_item_impl.cc
index dfb915e4dbd54610fdc58882ad77a39c34dfbd97..5e98b3b5aef392c792ebdd361a16e0812fff5ea2 100644
--- a/content/browser/download/download_item_impl.cc
+++ b/content/browser/download/download_item_impl.cc
@@ -68,9 +68,12 @@ void DeleteDownloadedFile(const base::FilePath& path) {
 // Wrapper around DownloadFile::Detach and DownloadFile::Cancel that
 // takes ownership of the DownloadFile and hence implicitly destroys it
 // at the end of the function.
-static void DownloadFileDetach(scoped_ptr<DownloadFile> download_file) {
+static base::FilePath DownloadFileDetach(
+    scoped_ptr<DownloadFile> download_file) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  base::FilePath full_path = download_file->FullPath();
   download_file->Detach();
+  return full_path;
 }
 
 static void DownloadFileCancel(scoped_ptr<DownloadFile> download_file) {
@@ -388,6 +391,22 @@ void DownloadItemImpl::Delete(DeleteReason reason) {
   // We have now been deleted.
 }
 
+void DownloadItemImpl::AcquireFileAndDeleteDownload(
+    const AcquireFileCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  if (download_file_) {
+    BrowserThread::PostTaskAndReplyWithResult(
+        BrowserThread::FILE, FROM_HERE,
+        base::Bind(&DownloadFileDetach, base::Passed(&download_file_)),
+        callback);
+  } else {
+    callback.Run(current_path_);
+  }
+  current_path_.clear();
+  Delete(DELETE_DUE_TO_USER_DISCARD);
+}
+
 void DownloadItemImpl::Remove() {
   VLOG(20) << __FUNCTION__ << "() download = " << DebugString(true);
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
@@ -1441,7 +1460,8 @@ void DownloadItemImpl::ReleaseDownloadFile(bool destroy_file) {
     BrowserThread::PostTask(
         BrowserThread::FILE, FROM_HERE,
         // Will be deleted at end of task execution.
-        base::Bind(&DownloadFileDetach, base::Passed(&download_file_)));
+        base::Bind(base::IgnoreResult(&DownloadFileDetach),
+                   base::Passed(&download_file_)));
   }
   // Don't accept any more messages from the DownloadFile, and null
   // out any previous "all data received".  This also breaks links to