Reverts third_party/protobuf: Update to HEAD (f52e188fe4)

third_party/protobuf/java/README.md

 Protocol Buffers - Google's data interchange format
 ===================================================
 
 [![Build Status](https://travis-ci.org/google/protobuf.svg?branch=master)](https://travis-ci.org/google/protobuf)
 
 Copyright 2008 Google Inc.
 
 This directory contains the Java Protocol Buffers runtime library.
 
 Installation - With Maven
 =========================
 
 The Protocol Buffers build is managed using Maven.  If you would
 rather build without Maven, see below.
 
 1) Install Apache Maven if you don't have it:
 
      http://maven.apache.org/
 
-2) Build the C++ code, or obtain a binary distribution of protoc (see
-   the toplevel [README.md](../README.md)). If you install a binary
-   distribution, make sure that it is the same version as this package.
-   If in doubt, run:
+2) Build the C++ code, or obtain a binary distribution of protoc.  If
+   you install a binary distribution, make sure that it is the same
+   version as this package.  If in doubt, run:
 
      $ protoc --version
 
    You will need to place the protoc executable in ../src.  (If you
    built it yourself, it should already be there.)
 
 3) Run the tests:
 
      $ mvn test
 
    If some tests fail, this library may not work correctly on your
    system.  Continue at your own risk.
 
 4) Install the library into your Maven repository:
 
      $ mvn install
 
 5) If you do not use Maven to manage your own build, you can build a
    .jar file to use:
 
      $ mvn package
 
    The .jar will be placed in the "target" directory.
 
-The above instructions will install 3 maven artifacts:
+Installation - 'Lite' Version - With Maven
+==========================================
 
-  * protobuf-java: The core Java Protocol Buffers library. Most users only
-                   need this artifact.
-  * protobuf-lite: The lite version of core Java Protobuf Buffers library. It
-                   is a subset of the core library and is used together with
-                   the 'lite' code generator flag to reduce generated code size
-                   for mobile.
-  * protobuf-java-util: Utilities to work with protos. It contains JSON support
-                        as well as utilities to work with proto3 well-known
-                        types.
+Building the 'lite' version of the Java Protocol Buffers library is
+the same as building the full version, except that all commands are
+run using the 'lite' profile.  (see
+http://maven.apache.org/guides/introduction/introduction-to-profiles.html)
+
+E.g. to install the lite version of the jar, you would run:
+
+    $ mvn install -P lite
+
+The resulting artifact has the 'lite' classifier.  To reference it
+for dependency resolution, you would specify it as:
+
+```
+  <dependency>
+    <groupId>com.google.protobuf</groupId>
+    <artifactId>protobuf-java</artifactId>
+    <version>${version}</version>
+    <classifier>lite</classifier>
+  </dependency>
+```
 
 Installation - Without Maven
 ============================
 
 If you would rather not install Maven to build the library, you may
 follow these instructions instead.  Note that these instructions skip
-running unit tests and only describes how to install the core protobuf
-library (without the util package).
+running unit tests.
 
 1) Build the C++ code, or obtain a binary distribution of protoc.  If
    you install a binary distribution, make sure that it is the same
    version as this package.  If in doubt, run:
 
      $ protoc --version
 
    If you built the C++ code without installing, the compiler binary
    should be located in ../src.
 
 2) Invoke protoc to build DescriptorProtos.java:
 
-     $ protoc --java_out=core/src/main/java -I../src \
+     $ protoc --java_out=src/main/java -I../src \
          ../src/google/protobuf/descriptor.proto
 
-3) Compile the code in core/src/main/java using whatever means you prefer.
+3) Compile the code in src/main/java using whatever means you prefer.
 
 4) Install the classes wherever you prefer.
 
-Compatibility Notice
-====================
-
-* Protobuf minor version releases are backwards-compatible. If your code
-  can build/run against the old version, it's expected to build/run against
-  the new version as well. Both binary compatibility and source compatibility
-  are guaranteed for minor version releases if the user follows the guideline
-  described in this section.
-
-* Protobuf major version releases may also be backwards-compatbile with the
-  last release of the previous major version. See the release notice for more
-  details.
-
-* APIs marked with the @ExperimentalApi annotation are subject to change. They
-  can be modified in any way, or even removed, at any time. Don't use them if
-  compatibility is needed. If your code is a library itself (i.e. it is used on
-  the CLASSPATH of users outside your own control), you should not use
-  experimental APIs, unless you repackage them (e.g. using ProGuard).
-
-* Deprecated non-experimental APIs will be removed two years after the release
-  in which they are first deprecated. You must fix your references before this
-  time. If you don't, any manner of breakage could result (you are not
-  guaranteed a compilation error).
-
-* Protobuf message interfaces/classes are designed to be subclassed by protobuf
-  generated code only. Do not subclass these message interfaces/classes
-  yourself. We may add new methods to the message interfaces/classes which will
-  break your own subclasses.
-
-* Don't use any method/class that is marked as "used by generated code only".
-  Such methods/classes are subject to change.
-
-* Protobuf LITE runtime APIs are not stable yet. They are subject to change even
-  in minor version releases.
-
-Documentation
-=============
+Usage
+=====
 
 The complete documentation for Protocol Buffers is available via the
 web at:
 
   https://developers.google.com/protocol-buffers/