Show download error message if sdcard is not available

chrome/browser/android/download/download_controller.h

 // Copyright 2016 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 42 matching lines @@
   // UMA histogram enum for download cancellation reasons. Keep this
   // in sync with MobileDownloadCancelReason in histograms.xml. This should be
   // append only.
   enum DownloadCancelReason {
     CANCEL_REASON_NOT_CANCELED = 0,
     CANCEL_REASON_ACTION_BUTTON,
     CANCEL_REASON_NOTIFICATION_DISMISSED,
     CANCEL_REASON_OVERWRITE_INFOBAR_DISMISSED,
     CANCEL_REASON_NO_STORAGE_PERMISSION,
     CANCEL_REASON_DANGEROUS_DOWNLOAD_INFOBAR_DISMISSED,
+    CANCEL_REASON_NO_EXTERNAL_STORAGE,
+    CANCEL_REASON_CANNOT_DETERMINE_DOWNLOAD_TARGET,
     CANCEL_REASON_MAX
   };
   static void RecordDownloadCancelReason(DownloadCancelReason reason);
 
  private:
   struct JavaObject;
   friend struct base::DefaultSingletonTraits<DownloadController>;
   DownloadController();
   ~DownloadController() override;
 
@@ skipping 37 matching lines @@
   JavaObject* GetJavaObject();
 
   JavaObject* java_object_;
 
   std::string default_file_name_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadController);
 };
 
 #endif  // CHROME_BROWSER_ANDROID_DOWNLOAD_DOWNLOAD_CONTROLLER_H_