Disabled soundcloud load test in SystemHealthBenchmarkSmokeTest.

Test is timing out. The 'play' test was already disabled; now the 'load'
test is also disabled.

TBR=nednguyen@chromium.org

Bug: 649392, 726439
Change-Id: I6eca533f0a9348adb0d567be1f6af907a603e0ae
Reviewed-on: https://chromium-review.googlesource.com/516923Reviewed-by: Matt Giuca <mgiuca@chromium.org>
Commit-Queue: Matt Giuca <mgiuca@chromium.org>
Cr-Commit-Position: refs/heads/master@{#474965}

tools/perf/benchmarks/system_health_smoke_test.py

@@ -45,6 +45,7 @@ _DISABLED_TESTS = frozenset({
   'benchmarks.system_health_smoke_test.SystemHealthBenchmarkSmokeTest.system_health.memory_desktop.long_running:tools:gmail-background',  # pylint: disable=line-too-long
 
   # Disable media tests in CQ. crbug.com/649392
+  'benchmarks.system_health_smoke_test.SystemHealthBenchmarkSmokeTest.system_health.memory_desktop.load:media:soundcloud',  # pylint: disable=line-too-long
   'benchmarks.system_health_smoke_test.SystemHealthBenchmarkSmokeTest.system_health.memory_desktop.play:media:soundcloud',  # pylint: disable=line-too-long
   'benchmarks.system_health_smoke_test.SystemHealthBenchmarkSmokeTest.system_health.memory_desktop.play:media:google_play_music',  # pylint: disable=line-too-long