[Downloads] Rework how hashes are calculated for download files.

chrome/browser/download/download_item_model.cc

 // 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.
 
 #include "chrome/browser/download/download_item_model.h"
 
 #include "base/i18n/number_formatting.h"
 #include "base/i18n/rtl.h"
 #include "base/metrics/field_trial.h"
 #include "base/strings/string16.h"
@@ skipping 161 matching lines @@
       break;
     case content::DOWNLOAD_INTERRUPT_REASON_SERVER_UNREACHABLE:
       string_id = IDS_DOWNLOAD_INTERRUPTED_STATUS_UNREACHABLE;
       break;
 
     case content::DOWNLOAD_INTERRUPT_REASON_NONE:
       NOTREACHED();
       // fallthrough
     case content::DOWNLOAD_INTERRUPT_REASON_SERVER_NO_RANGE:
     case content::DOWNLOAD_INTERRUPT_REASON_FILE_FAILED:
+    case content::DOWNLOAD_INTERRUPT_REASON_FILE_HASH_MISMATCH:

[asanka, 2016/03/04 22:08:06]

svaldez: note here and elsewhere that HASH_MISMATCH is not supposed to be an
error exposed to the user. Downloads is expected to recover automatically from
this error condition.

       string_id = IDS_DOWNLOAD_INTERRUPTED_STATUS;
   }
 
   return l10n_util::GetStringUTF16(string_id);
 }
 
 base::string16 InterruptReasonMessage(content::DownloadInterruptReason reason) {
   int string_id = IDS_DOWNLOAD_INTERRUPTED_STATUS;
   base::string16 status_text;
 
@@ skipping 63 matching lines @@
       string_id = IDS_DOWNLOAD_INTERRUPTED_DESCRIPTION_FORBIDDEN;
       break;
     case content::DOWNLOAD_INTERRUPT_REASON_SERVER_UNREACHABLE:
       string_id = IDS_DOWNLOAD_INTERRUPTED_DESCRIPTION_UNREACHABLE;
       break;
     case content::DOWNLOAD_INTERRUPT_REASON_NONE:
       NOTREACHED();
       // fallthrough
     case content::DOWNLOAD_INTERRUPT_REASON_SERVER_NO_RANGE:
     case content::DOWNLOAD_INTERRUPT_REASON_FILE_FAILED:
+    case content::DOWNLOAD_INTERRUPT_REASON_FILE_HASH_MISMATCH:
       string_id = IDS_DOWNLOAD_INTERRUPTED_STATUS;
   }
 
   status_text = l10n_util::GetStringUTF16(string_id);
 
   return status_text;
 }
 
 } // namespace
 
@@ skipping 444 matching lines @@
   if (!download_service)
     return;
 
   ChromeDownloadManagerDelegate* delegate =
       download_service->GetDownloadManagerDelegate();
   if (!delegate)
     return;
   delegate->OpenDownloadUsingPlatformHandler(download_);
   RecordDownloadOpenMethod(DOWNLOAD_OPEN_METHOD_USER_PLATFORM);
 }