Below mentioned browser_tests fails in linux64 official.desktop builder.

PPAPINaClPNaClNonSfiTest.NetworkMonitor
PPAPINaClPNaClNonSfiTest.UDPSocket_ParallelSend
PPAPINaClPNaClNonSfiTest.VideoDecoder
PPAPINaClPNaClNonSfiTest.UDPSocket_SetOption_1_0
PPAPINaClPNaClNonSfiTest.UDPSocket_SetOption_1_1
PPAPINaClPNaClNonSfiTest.UMA
PPAPINaClPNaClNonSfiTest.Core
PPAPINaClPNaClNonSfiTest.AudioConfig
PPAPINaClPNaClNonSfiTest.VideoDestination
PPAPINaClPNaClNonSfiTest.View_CreatedVisible
PPAPINaClPNaClNonSfiTest.InputEvent
PPAPINaClPNaClNonSfiTest.Graphics2D_Scroll
PPAPINaClPNaClNonSfiTest.VideoSource
GlobalConfirmInfoBarWithInfoBarDisabledTest.InfoBarsDisabled
PPAPINaClPNaClNonSfiTest.TCPSocketPrivate
PPAPIPrivateNaClPNaClNonSfiTest.FILEIO_Private
PPAPINaClPNaClNonSfiTest.UDPSocketPrivate_ConnectFailure
PPAPINaClPNaClNonSfiTest.UDPSocketPrivate_Broadcast
PPAPINaClPNaClNonSfiTest.NetAddress
PPAPINaClPNaClNonSfiTest.Graphics2D_Replace
PPAPINaClPNaClNonSfiTest.Var
PPAPINaClPNaClNonSfiTest.Graphics2D_Describe
PPAPINaClPNaClNonSfiTest.UDPSocket_ReadWrite
PPAPINaClPNaClNonSfiTest.TrueTypeFont
PPAPINaClPNaClNonSfiTest.FileIO
PPAPINaClPNaClNonSfiTest.MessageHandler
PPAPINaClPNaClNonSfiTest.URLRequest_SetProperty
PPAPINaClPNaClNonSfiTest.URLLoader2
PPAPINaClPNaClNonSfiTest.Memory
PPAPINaClPNaClNonSfiTest.UDPSocket_Broadcast
PPAPINaClPNaClNonSfiTest.Graphics2D_Flush
PPAPINaClPNaClNonSfiTest.Graphics2D_Paint
PPAPINaClPNaClNonSfiTest.WebSocket2
PPAPINaClPNaClNonSfiTest.URLLoader0
PPAPINaClPNaClNonSfiTest.UDPSocketPrivate_Connect
PPAPINaClPNaClNonSfiTest.TCPSocket
PPAPINaClPNaClNonSfiTest.WebSocket1
PPAPINaClPNaClNonSfiTest.URLLoader1
PPAPINaClPNaClNonSfiTest.Graphics2D_InitToZero
PPAPINaClPNaClNonSfiTest.PaintAggregator
PPAPINaClPNaClNonSfiTest.MediaStreamVideoTrack
PPAPINaClPNaClNonSfiTest.ImageData
PPAPINaClPNaClNonSfiTest.TraceEvent
PPAPINaClPNaClNonSfiTest.Console
PPAPINaClPNaClNonSfiTest.Graphics2D_BindNull
PPAPINaClPNaClNonSfiTest.MessageLoop_Post
PPAPINaClPNaClNonSfiTest.URLRequest_AppendDataToBody
PPAPINaClPNaClNonSfiTest.HostResolverPrivate_Resolve
PPAPINaClPNaClNonSfiTest.MouseCursor
PPAPINaClPNaClNonSfiTest.VarResource
PPAPINaClPNaClNonSfiTest.URLRequest_Stress
PPAPINaClPNaClNonSfiTest.MessageLoop_Basics
PPAPINaClPNaClNonSfiTest.FileRef1
PPAPINaClPNaClNonSfiTest.UDPSocketPrivate_SetSocketFeatureErrors
PPAPINaClPNaClNonSfiTest.HostResolver
PPAPINaClPNaClNonSfiTest.FileRef2
PPAPINaClPNaClNonSfiTest.URLLoader3
PPAPINaClPNaClNonSfiTest.UDPSocket_Multicast
PPAPINaClPNaClNonSfiTest.Graphics2D_Humongous
PPAPINaClPNaClNonSfiTest.Graphics2D_InvalidSize
PPAPINaClPNaClNonSfiTest.NetAddressPrivate
PPAPINaClPNaClNonSfiTest.NetworkProxy
PPAPINaClPNaClNonSfiTest.FileSystem
PPAPINaClPNaClNonSfiTest.UDPSocket_SetOption
PPAPINaClPNaClNonSfiTest.VideoEncoder
PPAPINaClPNaClNonSfiTest.AudioEncoder
PPAPINaClPNaClNonSfiTest.View
PPAPINaClPNaClNonSfiTest.Graphics3D
PPAPINaClPNaClNonSfiTest.HostResolverPrivate_ResolveIPv4
PPAPINaClPNaClNonSfiTest.TCPServerSocketPrivate
PPAPINaClPNaClNonSfiTest.URLRequest_CreateAndIsURLRequestInfo
PPAPINaClPNaClNonSfiTest.Graphics2D_InvalidResource
PPAPINaClPNaClNonSfiTest.PostMessage

Link to the Builder
===================
https://uberchromegw.corp.google.com/i/official.desktop/builders/linux64/builds/674

Link to the log file
====================
https://uberchromegw.corp.google.com/i/official.desktop/builders/linux64/builds/674/steps/browser_tests/logs/stdio

Error Log
=========
PPAPINaClPNaClNonSfiTest.AudioConfig (run #2):
[ RUN      ] PPAPINaClPNaClNonSfiTest.AudioConfig
Xlib:  extension "RANDR" missing on display ":9".
[3840:3840:1009/200749.271597:WARNING:password_store_factory.cc(241)] Using basic (unencrypted) store for password storage. See https://chromium.googlesource.com/chromium/src/+/master/docs/linux_password_storage.md for more information about password storage options.
[3840:3840:1009/200749.308411:WARNING:browser_main_loop.cc(294)] <unknown>: AT-SPI: Could not obtain desktop path or name

[3840:3840:1009/200749.313677:WARNING:browser_main_loop.cc(294)] <unknown>: AT-SPI: Could not obtain desktop path or name

[3840:3840:1009/200749.313754:WARNING:browser_main_loop.cc(294)] <unknown>: atk-bridge: get_device_events_reply: unknown signature
[3840:3840:1009/200749.313771:WARNING:browser_main_loop.cc(294)] <unknown>: atk-bridge: get_device_events_reply: unknown signature
[3840:3840:1009/200749.313786:WARNING:browser_main_loop.cc(294)] <unknown>: atk-bridge: GetRegisteredEvents returned message with unknown signature
[3840:3840:1009/200749.317926:WARNING:browser_main_loop.cc(294)] <unknown>: AT-SPI: Could not obtain desktop path or name

[3840:3840:1009/200749.317992:WARNING:browser_main_loop.cc(294)] <unknown>: atk-bridge: get_device_events_reply: unknown signature
[3840:3840:1009/200749.318030:WARNING:browser_main_loop.cc(294)] <unknown>: atk-bridge: get_device_events_reply: unknown signature
[3840:3840:1009/200749.318047:WARNING:browser_main_loop.cc(294)] <unknown>: atk-bridge: GetRegisteredEvents returned message with unknown signature
[3840:3913:1009/200749.391883:WARNING:embedded_test_server.cc(229)] Request not handled. Returning 404: /favicon.ico
[3840:3873:1009/200749.405326:ERROR:service_manager.cc(156)] Connection InterfaceProviderSpec prevented service: content_browser from binding interface: content::mojom::Child exposed by: nacl_loader
[3840:3873:1009/200749.410006:ERROR:nacl_process_host.cc(256)] NaCl process exited with status 62720 (0xf500)
[3840:3840:1009/200749.410255:INFO:CONSOLE(0)] "NativeClient: NaCl module crashed", source: http://127.0.0.1:50225/test_case.html?mode=nacl_pnacl_nonsfi&testcase=AudioConfig_RecommendSampleRate,AudioConfig_ValidConfigs,AudioConfig_InvalidConfigs, (0)
../../chrome/test/ppapi/ppapi_test.cc:250: Failure
      Expected: "PASS"
To be equal to: handler.message().c_str()
      Which is: "Plugin crashed. 'NaCl module crashed'"
[3889:3889:1009/200749.453069:WARNING:ipc_message_attachment_set.cc(49)] MessageAttachmentSet destroyed with unconsumed attachments: 0/1
[3889:3889:1009/200749.453125:WARNING:ipc_message_attachment_set.cc(49)] MessageAttachmentSet destroyed with unconsumed attachments: 0/1
[3889:3889:1009/200749.453142:WARNING:ipc_message_attachment_set.cc(49)] MessageAttachmentSet destroyed with unconsumed attachments: 0/1
[3889:3889:1009/200749.453153:WARNING:ipc_message_attachment_set.cc(49)] MessageAttachmentSet destroyed with unconsumed attachments: 0/1
[3889:3889:1009/200749.453174:WARNING:ipc_message_attachment_set.cc(49)] MessageAttachmentSet destroyed with unconsumed attachments: 0/1
[3889:3889:1009/200749.453189:WARNING:ipc_message_attachment_set.cc(49)] MessageAttachmentSet destroyed with unconsumed attachments: 0/1
[3840:3840:1009/200749.460333:INFO:chrome_cryptauth_service.cc(222)] Profile is not authenticated yet; waiting before starting CryptAuth managers.
[  FAILED  ] PPAPINaClPNaClNonSfiTest.AudioConfig, where TypeParam =  and GetParam() =  (1088 ms)

Flaky Information 
=================
PPAPINaClPNaClNonSfiTest.AudioConfig is passing in the latest build 

https://uberchromegw.corp.google.com/i/official.desktop/builders/linux64/builds/639

Build ranges checked for flakiness: 626 : 675
Number of times failed: 3 times out of 44 builds.

Unfortunately cannot find the culprit. Looping to Nico who made latest code change in ppapi_test.cc