Revert https://codereview.chromium.org/1291903002 (protobuf roll).

third_party/protobuf/benchmarks/readme.txt

-Contents
---------
-
-This folder contains three kinds of file:
-
-- Code, such as ProtoBench.java, to build the benchmarking framework.
-- Protocol buffer definitions (.proto files)
-- Sample data files
-
-If we end up with a lot of different benchmarks it may be worth
-separating these out info different directories, but while there are
-so few they might as well all be together.
-
-Running a benchmark (Java)
---------------------------
-
-1) Build protoc and the Java protocol buffer library. The examples
-   below assume a jar file (protobuf.jar) has been built and copied
-   into this directory.
-
-2) Build ProtoBench:
-   $ javac -d tmp -cp protobuf.jar ProtoBench.java
-   
-3) Generate code for the relevant benchmark protocol buffer, e.g.
-   $ protoc --java_out=tmp google_size.proto google_speed.proto
-   
-4) Build the generated code, e.g.
-   $ cd tmp
-   $ javac -d . -cp ../protobuf.jar benchmarks/*.java
-           
-5) Run the test. Arguments are given in pairs - the first argument
-   is the descriptor type; the second is the filename. For example:
-   $ java -cp .;../protobuf.jar com.google.protocolbuffers.ProtoBench
-          benchmarks.GoogleSize$SizeMessage1 ../google_message1.dat
-          benchmarks.GoogleSpeed$SpeedMessage1 ../google_message1.dat
-          benchmarks.GoogleSize$SizeMessage2 ../google_message2.dat
-          benchmarks.GoogleSpeed$SpeedMessage2 ../google_message2.dat
-          
-6) Wait! Each test runs for around 30 seconds, and there are 6 tests
-   per class/data combination. The above command would therefore take
-   about 12 minutes to run.
-
-   
-Benchmarks available
---------------------
-
-From Google:
-google_size.proto and google_speed.proto, messages
-google_message1.dat and google_message2.dat. The proto files are
-equivalent, but optimized differently.