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

chrome/browser/download/download_manager.cc

Index: chrome/browser/download/download_manager.cc
diff --git a/chrome/browser/download/download_manager.cc b/chrome/browser/download/download_manager.cc
index 6ef4a2b1e812ba36598d087e77f7925cacde2c3a..43adf177628bf1bb24608fb06f163a00ecbc8742 100644
--- a/chrome/browser/download/download_manager.cc
+++ b/chrome/browser/download/download_manager.cc
@@ -265,6 +265,44 @@ void DownloadManager::StartDownload(DownloadCreateInfo* info) {
       info, NewCallback(this, &DownloadManager::CheckDownloadUrlDone));
 }
 
+void DownloadManager::CheckForFilesRemoval() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  for (DownloadMap::iterator it = history_downloads_.begin();
+       it != history_downloads_.end(); ++it) {
+    DownloadItem* download_item = it->second;
+    if (download_item->IsComplete() && download_item->file_exists()) {
+        BrowserThread::PostTask(
+            BrowserThread::FILE, FROM_HERE,
+            NewRunnableMethod(this,
+                &DownloadManager::CheckForFilesRemovalOnFileThread,
+                it->first, download_item->GetTargetFilePath()));
+    }
+  }
+}
+
+void DownloadManager::CheckForFilesRemovalOnFileThread(
+    int64 db_handle, const FilePath& path) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  bool file_exists = file_util::PathExists(path);
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      NewRunnableMethod(this,
+                        &DownloadManager::OnFilesRemovalDetected,
+                        db_handle, file_exists));
+}
+
+void DownloadManager::OnFilesRemovalDetected(

[Randy Smith (Not in Mondays), 2011/05/12 20:21:17]

Given that we're doing single file checks now, we should change the plural in
the name to a singular (Files->File).

[haraken1, 2011/05/13 14:08:17]

Done.

+    int64 db_handle, bool file_exists) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (!file_exists) {

[Randy Smith (Not in Mondays), 2011/05/12 20:21:17]

Given that this function doesn't do anything if file_exists is false, how about
removing that argument from the function signature and not sending the response
message from the file thread if the file is still there?

[haraken1, 2011/05/13 14:08:17]

Done.

+    DownloadMap::iterator it = history_downloads_.find(db_handle);
+    if (it != history_downloads_.end()) {
+      DownloadItem* download_item = it->second;
+      download_item->OnDownloadedFileRemoved();
+    }
+  }
+}
+
 void DownloadManager::CheckDownloadUrlDone(DownloadCreateInfo* info,
                                            bool is_dangerous_url) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));