Mountain Lion: use the system download progress.

chrome/browser/download/download_status_updater.cc

Index: chrome/browser/download/download_status_updater.cc
diff --git a/chrome/browser/download/download_status_updater.cc b/chrome/browser/download/download_status_updater.cc
index 817e4184268926339bd599dc431f2ca5429911e2..9cebbb03319972f0654237560e1ad515e0a0c456 100644
--- a/chrome/browser/download/download_status_updater.cc
+++ b/chrome/browser/download/download_status_updater.cc
@@ -100,11 +100,32 @@ void DownloadStatusUpdater::UpdateItem(content::DownloadItem* download) {
     if (!ContainsKey(items_, download)) {
       items_.insert(download);
       download->AddObserver(this);
+      UpdateDownloadProgressForItemStarted(download);
+    } else {
+      UpdateDownloadProgressForItemProgressed(download);
     }
   } else {
     if (ContainsKey(items_, download)) {
+      UpdateDownloadProgressForItemCompleted(download);
       items_.erase(download);
       download->RemoveObserver(this);
     }
   }
 }
+
+// All platforms track overall download progress via
+// UpdateAppIconDownloadProgress(); these allow for tracking the progress of
+// individual downloads.
+#if !defined(OS_MACOSX) && !defined(OS_WIN)
+void DownloadStatusUpdater::UpdateDownloadProgressForItemStarted(
+    content::DownloadItem* download) {
+}
+
+void DownloadStatusUpdater::UpdateDownloadProgressForItemProgressed(
+    content::DownloadItem* download) {
+}
+
+void DownloadStatusUpdater::UpdateDownloadProgressForItemCompleted(
+    content::DownloadItem* download) {
+}
+#endif  // OS_MACOSX