If a download is initiated by download attribute, don't use stream viewer

content/browser/android/download_controller_android_impl.h

 // Copyright (c) 2012 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.
 
 // This class pairs with DownloadController on Java side to forward requests
 // for GET downloads to the current DownloadListener. POST downloads are
 // handled on the native side.
 //
 // Both classes are Singleton classes. C++ object owns Java object.
 //
@@ skipping 77 matching lines @@
   DownloadControllerAndroidImpl();
   ~DownloadControllerAndroidImpl() override;
 
   // Helper method for implementing AcquireFileAccessPermission().
   bool HasFileAccessPermission(
       base::android::ScopedJavaLocalRef<jobject> j_content_view_core);
 
   // DownloadControllerAndroid implementation.
   void CreateGETDownload(int render_process_id,
                          int render_view_id,
-                         int request_id) override;
+                         int request_id,
+                         bool must_download) override;
   void OnDownloadStarted(DownloadItem* download_item) override;
   void StartContextMenuDownload(const ContextMenuParams& params,
                                 WebContents* web_contents,
                                 bool is_link,
                                 const std::string& extra_headers) override;
   void DangerousDownloadValidated(WebContents* web_contents,
                                   const std::string& download_guid,
                                   bool accept) override;
 
   // DownloadItem::Observer interface.
@@ skipping 10 matching lines @@
   void DoLoadCookies(const DownloadInfoAndroid& info,
                      const GetDownloadInfoCB& callback,
                      const GlobalRequestID& global_id);
   void OnCookieResponse(DownloadInfoAndroid info,
                         const GetDownloadInfoCB& callback,
                         const std::string& cookie);
   void StartDownloadOnUIThread(const GetDownloadInfoCB& callback,
                                const DownloadInfoAndroid& info);
   void StartAndroidDownload(int render_process_id,
                             int render_view_id,
+                            bool must_download,
                             const DownloadInfoAndroid& info);
   void StartAndroidDownloadInternal(int render_process_id,
                                     int render_view_id,
+                                    bool must_download,
                                     const DownloadInfoAndroid& info,
                                     bool allowed);
 
   // The download item contains dangerous file types.
   void OnDangerousDownload(DownloadItem *item);
 
   base::android::ScopedJavaLocalRef<jobject> GetContentViewCoreFromWebContents(
       WebContents* web_contents);
 
   // Creates Java object if it is not created already and returns it.
   JavaObject* GetJavaObject();
 
   JavaObject* java_object_;
 
   std::string default_file_name_;
 
   ScopedVector<DeferredDownloadObserver> deferred_downloads_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadControllerAndroidImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ANDROID_DOWNLOAD_CONTROLLER_ANDROID_IMPL_H_