Disable blink_perf.canvas on linux again.

This was re-enabled again temporarily to see if https://codereview.chromium.org/1142603002 fixed the issue, which unfortunately it didn't.

BUG=488059
CQ_EXTRA_TRYBOTS=tryserver.chromium.perf:linux_perf_bisect;tryserver.chromium.perf:mac_perf_bisect;tryserver.chromium.perf:win_perf_bisect;tryserver.chromium.perf:android_nexus5_perf_bisect

Review URL: https://codereview.chromium.org/1139243002

Cr-Commit-Position: refs/heads/master@{#330259}

tools/perf/benchmarks/blink_perf.py

@@ -167,7 +167,8 @@ class BlinkPerfCSS(benchmark.Benchmark):
     return CreatePageSetFromPath(path, SKIPPED_FILE)
 
 
-@benchmark.Disabled('win')  # http://crbug.com/488493
+@benchmark.Disabled('win',   # http://crbug.com/488493
+                    'linux') # http://crbug.com/488059
 class BlinkPerfCanvas(benchmark.Benchmark):
   tag = 'canvas'
   test = _BlinkPerfMeasurement