[Telemetry] Expect to skip smoothness.maps on low-end devices

Certain devices have ARM GPUs that report support of certain WebGL features but
fail to actually support them, causing smoothness.maps to fail. This CL adds
WebGLLowEndExpectations to skip tests like smoothness.maps on such devices.

BUG=464731
R=dtu,kbr@chromium.org,sullivan

Review URL: https://codereview.chromium.org/1030693002

Cr-Commit-Position: refs/heads/master@{#321848}

tools/perf/benchmarks/smoothness.py

@@ -69,6 +69,10 @@ class SmoothnessMaps(benchmark.Benchmark):
   test = smoothness.Smoothness
   page_set = page_sets.MapsPageSet
 
+  @classmethod
+  def CreateExpectations(cls):
+    return webgl_expectations.MapsExpectations()
+
   @classmethod
   def Name(cls):
     return 'smoothness.maps'

tools/perf/benchmarks/webgl_expectations.py

@@ -8,3 +8,9 @@ class WebGLExpectations(test_expectations.TestExpectations):
   def SetExpectations(self):
     self.Skip('*', ['arm', 'broadcom', 'hisilicon', 'imagination', 'qualcomm',
                     'vivante'], bug=462729)
+
+
+class MapsExpectations(test_expectations.TestExpectations):
+  """Defines expectations to skip intensive tests on low-end devices."""
+  def SetExpectations(self):
+    self.Skip('*', ['arm'], bug=464731)