Browser: choose save or play after open an a/v link

Add a feature for carrier. When open an audio or video link,change
to prompt a dialog to let user choose save or play this media.

Change-Id: Ie098a8bf1d37bbf85b55b8b642f4b3e45d921f6c
diff --git a/src/com/android/browser/Controller.java b/src/com/android/browser/Controller.java
index 7b7fcd4..292a2b0 100644
--- a/src/com/android/browser/Controller.java
+++ b/src/com/android/browser/Controller.java
@@ -1036,9 +1036,9 @@
             String contentDisposition, String mimetype, String referer,
             long contentLength) {
         WebView w = tab.getWebView();
-        DownloadHandler.onDownloadStart(mActivity, url, userAgent,
+        boolean ret = DownloadHandler.onDownloadStart(mActivity, url, userAgent,
                 contentDisposition, mimetype, referer, w.isPrivateBrowsingEnabled());
-        if (w.copyBackForwardList().getSize() == 0) {
+        if (ret == false && w.copyBackForwardList().getSize() == 0) {
             // This Tab was opened for the sole purpose of downloading a
             // file. Remove it.
             if (tab == mTabControl.getCurrentTab()) {