Move view change analytics tracking into DirectoryModel where implementation details can be hidden.

ui/file_manager/file_manager/common/js/importer_common.js

Index: ui/file_manager/file_manager/common/js/importer_common.js
diff --git a/ui/file_manager/file_manager/common/js/importer_common.js b/ui/file_manager/file_manager/common/js/importer_common.js
index c03b8237506b776c94dcfa996edae7f8ee4dfbdf..02aa42b07bfa66a21a38fdc7fba72245cd8cd5e4 100644
--- a/ui/file_manager/file_manager/common/js/importer_common.js
+++ b/ui/file_manager/file_manager/common/js/importer_common.js
@@ -197,6 +197,28 @@ importer.isMediaDirectory = function(entry, volumeInfoProvider) {
 };
 
 /**
+ * @param {!DirectoryEntry} directory Presumably the root of a filesystem.
+ * @return {!Promise<boolean>} True if the directory has a media directory
+ *     (like DCIM) as a direct child.
+ */
+importer.hasMediaDirectory = function(directory) {

[mtomasz, 2015/03/24 01:34:58]

nit: This may be slow. Are we fine with it? Instead we could just go the other
way and try to resolve possible roots, as there are only two.

[Steve McKay, 2015/03/24 22:39:20]

I agree about this possibly being slow. Fixed.

+  var hasMediaDirectory = false;
+  return importer.listEntries_(
+      directory,
+      /** @param {!Entry} entry */
+      function(entry) {
+        if (!hasMediaDirectory &&
+            entry.name.toUpperCase() in importer.ValidImportRoots_) {
+          hasMediaDirectory = true;
+        }
+      })
+      .then(
+          function() {
+            return hasMediaDirectory;
+          });
+};
+
+/**
  * @return {!Promise<boolean>} Resolves with true when Cloud Import feature
  *     is enabled.
  */
@@ -329,7 +351,7 @@ importer.getUnownedHistoryFiles_ = function(machineId) {
       .then(
           /** @param {!DirectoryEntry} root */
           function(root) {
-            return fileOperationUtil.listEntries(
+            return importer.listEntries_(
                 root,
                 /** @param {Entry} entry */
                 function(entry) {
@@ -375,6 +397,37 @@ importer.getHistoryFiles = function() {
 };
 
 /**
+ * Calls {@code callback} for each child entry of {@code directory}.
+ *
+ * @param {!DirectoryEntry} directory
+ * @param {function(!Entry)} callback
+ * @return {!Promise} Resolves when listing is complete.
+ * @private
+ */
+importer.listEntries_ = function(directory, callback) {
+  return new Promise(
+      function(resolve, reject) {
+        var reader = directory.createReader();
+
+        var readEntries = function() {
+          reader.readEntries (
+              /** @param {!Array<!Entry>} entries */
+              function(entries) {
+                if (entries.length === 0) {
+                  resolve(undefined);
+                  return;
+                }
+                entries.forEach(callback);

[mtomasz, 2015/03/24 01:34:58]

nit: I think this should cause a js compile error, as forEach requires a
callback with 3 arguments. Could you double check?

[Steve McKay, 2015/03/24 22:39:20]

Callback is required, all others are optional.

+                readEntries();
+              },
+              reject);
+        };
+
+        readEntries();
+      });
+};
+
+/**
  * A Promise wrapper that provides public access to resolve and reject methods.
  *
  * @constructor