Disabling blink_perf.pywebsocket due to flake.

tools/perf/benchmarks/blink_perf.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import os
 
 from core import path_util
 from core import perf_benchmark
 
 from telemetry import benchmark
@@ skipping 299 matching lines @@
   @classmethod
   def Name(cls):
     return 'blink_perf.xml_http_request'
 
   def CreateStorySet(self, options):
     path = os.path.join(BLINK_PERF_BASE_DIR, 'XMLHttpRequest')
     return CreateStorySetFromPath(path, SKIPPED_FILE)
 
 
 # Disabled on Windows and ChromeOS due to https://crbug.com/521887
-@benchmark.Disabled('win', 'chromeos')
+#@benchmark.Disabled('win', 'chromeos')
+# Disabling on remaining platforms due to heavy flake https://crbug.com/646938
+@benchmark.Disabled('all')
 class BlinkPerfPywebsocket(perf_benchmark.PerfBenchmark):
   """The blink_perf.pywebsocket tests measure turn-around-time of 10MB
   send/receive for XHR, Fetch API and WebSocket. We might ignore < 10%
   regressions, because the tests are noisy and such regressions are
   often unreproducible (https://crbug.com/549017).
   """
   tag = 'pywebsocket'
   test = _BlinkPerfMeasurement
 
   @classmethod
   def Name(cls):
     return 'blink_perf.pywebsocket'
 
   def CreateStorySet(self, options):
     path = os.path.join(BLINK_PERF_BASE_DIR, 'Pywebsocket')
     return CreateStorySetFromPath(
         path, SKIPPED_FILE,
         shared_page_state_class=_SharedPywebsocketPageState)
 
   @classmethod
   def ShouldDisable(cls, possible_browser):
     return cls.IsSvelte(possible_browser)  # http://crbug.com/551950