Gallery: Add debugMe method to Gallery.

ui/file_manager/gallery/js/gallery.js

Index: ui/file_manager/gallery/js/gallery.js
diff --git a/ui/file_manager/gallery/js/gallery.js b/ui/file_manager/gallery/js/gallery.js
index 899b7fffc553302fe1b5994297a379cc0d4280a1..37fe5e3cb5ca4f06cf0d3e6abbad63c61727cca2 100644
--- a/ui/file_manager/gallery/js/gallery.js
+++ b/ui/file_manager/gallery/js/gallery.js
@@ -879,6 +879,13 @@ Gallery.prototype.updateButtons_ = function() {
 };
 
 /**
+ * Enters the debug mode.
+ */
+Gallery.prototype.debugMe = function() {
+  this.mosaicMode_.debugMe();
+};
+
+/**
  * Singleton gallery.
  * @type {Gallery}
  */
@@ -901,3 +908,10 @@ window.initialize = function(backgroundComponents) {
 window.loadEntries = function(entries, selectedEntries) {
   gallery.load(entries, selectedEntries);
 };
+
+/**
+ * Enteres the debug mode.
+ */
+window.debugMe = function() {
+  gallery.debugMe();
+};