[MD Extensions] Add the source type on the details page for an extension

chrome/browser/resources/md_extensions/item_source.js

Index: chrome/browser/resources/md_extensions/item_source.js
diff --git a/chrome/browser/resources/md_extensions/item_source.js b/chrome/browser/resources/md_extensions/item_source.js
new file mode 100644
index 0000000000000000000000000000000000000000..3b16ea9bbd3dfc63ada6739814b654a8174b9f56
--- /dev/null
+++ b/chrome/browser/resources/md_extensions/item_source.js
@@ -0,0 +1,52 @@
+// Copyright 2016 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.
+
+// Closure compiler won't let this be declared inside cr.define().
+/** @enum {string} */
+var SourceType = {
+  WEBSTORE: 'webstore',
+  POLICY: 'policy',
+  SIDELOADED: 'sideloaded',
+  UNPACKED: 'unpacked',
+};
+
+cr.define('extensions', function() {
+  /**
+   * @param {chrome.developerPrivate.ExtensionInfo} item
+   * @return {SourceType}
+   */
+  function getItemSource(item) {
+    if (item.controlledInfo &&
+        item.controlledInfo.type ==
+            chrome.developerPrivate.ControllerType.POLICY) {
+      return SourceType.POLICY;
+    }
+    if (item.location == chrome.developerPrivate.Location.THIRD_PARTY)
+      return SourceType.SIDELOADED;
+    if (item.location == chrome.developerPrivate.Location.UNPACKED)
+      return SourceType.UNPACKED;
+    return SourceType.WEBSTORE;
+  }
+
+  /**
+   * @param {SourceType} source
+   * @return {string}
+   */
+  function getItemSourceString(source) {
+    switch (source) {
+      case SourceType.POLICY:
+        return loadTimeData.getString('itemSourcePolicy');
+      case SourceType.SIDELOADED:
+        return loadTimeData.getString('itemSourceSideloaded');
+      case SourceType.UNPACKED:
+        return loadTimeData.getString('itemSourceUnpacked');
+      case SourceType.WEBSTORE:
+        return loadTimeData.getString('itemSourceWebstore');
+    }
+    assertNotReached();
+  }
+
+  return {getItemSource: getItemSource,
+          getItemSourceString: getItemSourceString};
+});