Disable blink_perf.canvas on Android One

Rationale: The benchmark is consistently failing on the "Android One
Perf (2)" bot (see the associated bug).

BUG=593973
TBR=skyostil
CQ_EXTRA_TRYBOTS=tryserver.chromium.perf:android_s5_perf_cq;tryserver.chromium.perf:winx64_10_perf_cq;tryserver.chromium.perf:mac_retina_perf_cq;tryserver.chromium.perf:linux_perf_cq

Review URL: https://codereview.chromium.org/1804413004

Cr-Commit-Position: refs/heads/master@{#381741}

tools/perf/benchmarks/blink_perf.py

@@ -177,6 +177,10 @@ class BlinkPerfCanvas(perf_benchmark.PerfBenchmark):
   tag = 'canvas'
   test = _BlinkPerfMeasurement
 
+  @classmethod
+  def ShouldDisable(cls, possible_browser):
+    return cls.IsSvelte(possible_browser)  # http://crbug.com/593973.
+
   @classmethod
   def Name(cls):
     return 'blink_perf.canvas'