Enable loading.mobile benchmark on Android except reference and webview

tools/perf/benchmarks/loading.py

Index: tools/perf/benchmarks/loading.py
diff --git a/tools/perf/benchmarks/loading.py b/tools/perf/benchmarks/loading.py
index f8c896c814006008f6322bf56436b9f8dfd5e5f5..af402133f754f0eaa88ee2d02b3b889d473b10af 100644
--- a/tools/perf/benchmarks/loading.py
+++ b/tools/perf/benchmarks/loading.py
@@ -10,7 +10,7 @@ from telemetry import benchmark
 from telemetry.page import cache_temperature
 
 
-@benchmark.Disabled('all')  # crbug.com/654215
+@benchmark.Enabled('android')
 class LoadingMobile(perf_benchmark.PerfBenchmark):
   """ A benchmark measuring loading performance of mobile sites. """
 
@@ -20,6 +20,18 @@ class LoadingMobile(perf_benchmark.PerfBenchmark):
     return page_cycler_v2.TimelineBasedMeasurementOptionsForLoadingMetric()
 
   @classmethod
+  def ShouldDisable(cls, possible_browser):
+    # crbug.com/619254
+    if possible_browser.browser_type == 'reference':
+      return True
+
+    # crbug.com/651188
+    if possible_browser.browser_type == 'android-webview':
+      return True
+
+    return False
+
+  @classmethod
   def Name(cls):
     return 'loading.mobile'