Implement chrome.downloads.onDeterminingFilename() to allow extensions to participate in the download filename determination process.

Docs staged: http://basho.cam.corp.google.com:8000/extensions/downloads.html#event-onDeterminingFilename

Example:
chrome.downloads.onDeterminingFilename.addListener(function(item, suggest) {
  suggest({filename: item.filename, overwrite: true});
});
chrome.downloads.onDeterminingFilename.addListener(function(item, suggest) {
  window.setTimeout(function() {
    suggest({filename: item.mime.split('/')[0] + '/' + item.filename, overwrite: false});
  }, 1);
  return true;  // handling asynchronously
});

BUG=12133
BUG=68108

Review URL: https://chromiumcodereview.appspot.com/11574006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@185811 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 25 insertions, 0 deletions

diff --git a/chrome/common/extensions/docs/examples/api/downloads/downloads_overwrite/bg.js b/chrome/common/extensions/docs/examples/api/downloads/downloads_overwrite/bg.js
new file mode 100644
index 0000000..d7d9047
--- /dev/null
+++ b/chrome/common/extensions/docs/examples/api/downloads/downloads_overwrite/bg.js
@@ -0,0 +1,11 @@
+// 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.
+
+// Force all downloads to overwrite any existing files instead of inserting
+// ' (1)', ' (2)', etc.
+
+chrome.downloads.onDeterminingFilename.addListener(function(item, suggest) {
+  suggest({filename: item.filename,
+           overwrite: true});
+});
diff --git a/chrome/common/extensions/docs/examples/api/downloads/downloads_overwrite/manifest.json b/chrome/common/extensions/docs/examples/api/downloads/downloads_overwrite/manifest.json
new file mode 100644
index 0000000..c1f8999
--- /dev/null
+++ b/chrome/common/extensions/docs/examples/api/downloads/downloads_overwrite/manifest.json
@@ -0,0 +1,14 @@
+{
+  "name": "Downloads Overwrite Existing Files",
+  "description": "All downloads overwrite existing files instead of adding ' (1)', ' (2)', etc.",
+  "version": "1",
+  "minimum_chrome_version": "26.0.1428",
+  "background": {
+    "scripts": ["bg.js"],
+    "persistent": false
+  },
+  "permissions": [
+    "downloads"
+  ],
+  "manifest_version": 2
+}