Detect removed files and reflect the state in chrome://downloads and the download shelf

chrome/browser/download/download_util.cc

 // Copyright (c) 2011 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.
 //
 // Download utility implementation
 
 #include "chrome/browser/download/download_util.h"
 
 #if defined(OS_WIN)
 #include <shobjidl.h>
@@ skipping 646 matching lines @@
     file_value->SetInteger("percent",
         static_cast<int>(download->PercentComplete()));
     file_value->SetInteger("received",
         static_cast<int>(download->received_bytes()));
   } else if (download->IsCancelled()) {
     file_value->SetString("state", "CANCELLED");
   } else if (download->IsComplete()) {
     if (download->safety_state() == DownloadItem::DANGEROUS) {
       file_value->SetString("state", "DANGEROUS");
     } else {
-      file_value->SetString("state", "COMPLETE");
+      bool path_exists = true;

[Paweł Hajdan Jr., 2011/04/27 08:53:30]

It seems like you're checking whether a path exists. Why don't you use one of
the functions from base/file_util?

+#if defined(OS_WIN)
+      if (GetFileAttributes(
+              download->GetTargetFilePath().value().c_str()) ==
+          INVALID_FILE_ATTRIBUTES)
+        path_exists = false;
+#elif defined(OS_POSIX)
+      if (access(download->GetTargetFilePath().value().c_str(), F_OK) != 0)
+        path_exists = false;
+#else

[Paweł Hajdan Jr., 2011/04/27 08:53:30]

A "dangling else" like that is generally dangerous for portable code. The #if
will probably disappear, but a general tip is please put a NOTIMPLEMENTED(), or
#error in such an else to prevent a _silent_ failure on (hypothetical) platforms
not covered by OS_WIN and OS_POSIX.

+#endif
+      if (path_exists) {

[Paweł Hajdan Jr., 2011/04/27 08:53:30]

nit: It's probably cleaner to use a ternary operator like SetString("state",
path_exists ? "COMPLETE" : "REMOVED");

+        file_value->SetString("state", "COMPLETE");
+      } else {
+        file_value->SetString("state", "REMOVED");
+      }
     }
   }
 
   file_value->SetInteger("total",
       static_cast<int>(download->total_bytes()));
 
   return file_value;
 }
 
 string16 GetProgressStatusText(DownloadItem* download) {
@@ skipping 212 matching lines @@
     // Extensions that are not from the gallery are considered dangerous.
     ExtensionService* service = profile->GetExtensionService();
     if (!service ||
         !service->IsDownloadFromGallery(info->url(), info->referrer_url))
       return true;
   }
   return false;
 }
 
 }  // namespace download_util