Index: wp-includes/class-wp-customize-manager.php
===================================================================
--- wp-includes/class-wp-customize-manager.php	(revision 22241)
+++ wp-includes/class-wp-customize-manager.php	(working copy)
@@ -259,6 +259,23 @@
 	}
 
 	/**
+	 * Update registered section titles.
+	 *
+	 * @since 3.5.0
+	 *
+	 * @param array $titles Array of section titles.
+	 *
+	 */
+	public function update_section_titles( $titles = null ) {
+		if( !is_array($titles) )
+			return;
+
+		foreach( $titles as $title => $label )
+			if( in_array( $title, array_keys($this->sections) ) )
+				$this->sections[$title]->title = $label;
+	}
+
+	/**
 	 * Checks if the current theme is active.
 	 *
 	 * @since 3.4.0