[downloads] Move platform specific code out of DownloadTargetDeterminer.

android_webview/browser/aw_download_manager_delegate.cc

Index: android_webview/browser/aw_download_manager_delegate.cc
diff --git a/android_webview/browser/aw_download_manager_delegate.cc b/android_webview/browser/aw_download_manager_delegate.cc
index e6e3f4f7a2716737db997d8e33ec1c07584d8f0d..b455bcaf8bb759cf20679e367b63543d33935584 100644
--- a/android_webview/browser/aw_download_manager_delegate.cc
+++ b/android_webview/browser/aw_download_manager_delegate.cc
@@ -20,8 +20,8 @@ bool AwDownloadManagerDelegate::DetermineDownloadTarget(
   // could have already finished by the time DownloadStarting is called.
   callback.Run(base::FilePath() /* Empty file path for cancel */,
                content::DownloadItem::TARGET_DISPOSITION_OVERWRITE,
-               content::DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS,
-               base::FilePath());
+               content::DOWNLOAD_DANGER_TYPE_NOT_DANGEROUS, base::FilePath(),
+               content::DOWNLOAD_INTERRUPT_REASON_USER_CANCELED);
   return true;
 }