Add updated StorageProvider sample, merge _index with existing file.

Change-Id: I63d691929d2b30cedaafa5ede900670c59d4f83d
(cherry picked from commit 99acac3adb)

samples/browseable/StorageProvider/src/com.example.android.common/logger/LogNode.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.example.android.common.logger;
+
+/**
+ * Basic interface for a logging system that can output to one or more targets.
+ * Note that in addition to classes that will output these logs in some format,
+ * one can also implement this interface over a filter and insert that in the chain,
+ * such that no targets further down see certain data, or see manipulated forms of the data.
+ * You could, for instance, write a "ToHtmlLoggerNode" that just converted all the log data
+ * it received to HTML and sent it along to the next node in the chain, without printing it
+ * anywhere.
+ */
+public interface LogNode {
+
+    /**
+     * Instructs first LogNode in the list to print the log data provided.
+     * @param priority Log level of the data being logged.  Verbose, Error, etc.
+     * @param tag Tag for for the log data.  Can be used to organize log statements.
+     * @param msg The actual message to be logged. The actual message to be logged.
+     * @param tr If an exception was thrown, this can be sent along for the logging facilities
+     *           to extract and print useful information.
+     */
+    public void println(int priority, String tag, String msg, Throwable tr);
+
+}