Pasting error here for easy reference.
Looks like there is a library(libjli.so) failed to load during javac. Probably not related to cronet's perf app.

[700/5902] ACTION //build/android/pylib/device/commands:chromium_commands__compile_java__javac(//build/toolchain/android:arm64)
FAILED: gen/build/android/pylib/device/commands/chromium_commands__compile_java__javac.d gen/build/android/pylib/device/commands/chromium_commands__compile_java.javac.jar gen/build/android/pylib/device/commands/chromium_commands__compile_java.javac.jar.md5.stamp 
python ../../build/android/gyp/javac.py --depfile=gen/build/android/pylib/device/commands/chromium_commands__compile_java__javac.d --jar-path=gen/build/android/pylib/device/commands/chromium_commands__compile_java.javac.jar --java-srcjars=\[\] --java-srcjars=@FileArg\(gen/build/android/pylib/device/commands/chromium_commands.build_config:javac:srcjars\) --classpath=@FileArg\(gen/build/android/pylib/device/commands/chromium_commands.build_config:javac:interface_classpath\) --bootclasspath=lib.java/android.interface.jar --chromium-code=1 @gen/build/android/pylib/device/commands/chromium_commands.sources
Traceback (most recent call last):
  File "../../build/android/gyp/javac.py", line 441, in <module>
    sys.exit(main(sys.argv[1:]))
  File "../../build/android/gyp/javac.py", line 437, in main
    pass_changes=True)
  File "/b/build/slave/Android_Cronet_Marshmallow_64bit_Perf/build/src/build/android/gyp/util/build_utils.py", line 536, in CallAndWriteDepfileIfStale
    pass_changes=True)
  File "/b/build/slave/Android_Cronet_Marshmallow_64bit_Perf/build/src/build/android/gyp/util/md5_check.py", line 87, in CallAndRecordIfStale
    function(*args)
  File "/b/build/slave/Android_Cronet_Marshmallow_64bit_Perf/build/src/build/android/gyp/util/build_utils.py", line 520, in on_stale_md5
    function(*args)
  File "../../build/android/gyp/javac.py", line 431, in <lambda>
    classpath_inputs),
  File "../../build/android/gyp/javac.py", line 212, in _OnStaleMd5
    attempt_build()
  File "../../build/android/gyp/javac.py", line 210, in <lambda>
    stderr_filter=ColorJavacOutput)
  File "/b/build/slave/Android_Cronet_Marshmallow_64bit_Perf/build/src/build/android/gyp/util/build_utils.py", line 174, in CheckOutput
    raise CalledProcessError(cwd, args, stdout + stderr)
util.build_utils.CalledProcessError: Command failed: ( cd /b/build/slave/Android_Cronet_Marshmallow_64bit_Perf/build/src/out/Release; javac -g -encoding UTF-8 -classpath '' -sourcepath '' -bootclasspath lib.java/android.interface.jar -source 1.7 -target 1.7 -Xlint:unchecked -Xlint:deprecation -d /tmp/tmpI8hqj8/classes ../../build/android/pylib/device/commands/java/src/org/chromium/android/commands/unzip/Unzip.java )
javac: error while loading shared libraries: libjli.so: cannot open shared object file: No such file or directory

Seems like some of the new bots aren't quite ready for showtime.

 Issue 634951  has been merged into this issue.

Looking.

The jdk & jre installed on that machine was broken/missing, so I reinstalled them. Let see if that helps.

got a new one:

FAILED: gen/components/cronet/android/generate_javadoc.d 
python ../../components/cronet/tools/generate_javadoc.py --output-dir cronet --input-dir ../../components/cronet --overview-file cronet/README.md.html --readme-file ../../components/cronet/README.md --depfile gen/components/cronet/android/generate_javadoc.d --lib-java-dir lib.java/components/cronet/android
Traceback (most recent call last):
  File "../../components/cronet/tools/generate_javadoc.py", line 74, in <module>
    sys.exit(main())
  File "../../components/cronet/tools/generate_javadoc.py", line 64, in main
    GenerateJavadoc(options)
  File "../../components/cronet/tools/generate_javadoc.py", line 44, in GenerateJavadoc
    stdout = build_utils.CheckOutput(javadoc_cmd, cwd=working_dir)
  File "/b/build/slave/Android_Cronet_Marshmallow_64bit_Perf/build/src/build/android/gyp/util/build_utils.py", line 164, in CheckOutput
    stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=cwd, env=env)
  File "/usr/lib/python2.7/subprocess.py", line 710, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1327, in _execute_child
    raise child_exception
OSError: [Errno 13] Permission denied

Hmmm, this host is really having some issues. It didn't have ant installed, so I threw it on there and restarted. If it runs into another problem, we may need to just re-image it.

... I wonder what this bot was in another life.

Looks like this is fixed.