[Telemetry] Explicitly define Name() method for all perf benchmarks

tools/perf/benchmarks/power.py

Index: tools/perf/benchmarks/power.py
diff --git a/tools/perf/benchmarks/power.py b/tools/perf/benchmarks/power.py
index ab96a59f476f18a70cf6cada7a33da404505717a..d697f1bd1c81c071a40c45963cef0ef3e4644764 100644
--- a/tools/perf/benchmarks/power.py
+++ b/tools/perf/benchmarks/power.py
@@ -9,17 +9,22 @@ from telemetry import benchmark
 
 @benchmark.Enabled('android')
 class PowerAndroidAcceptance(benchmark.Benchmark):
-
   """Android power acceptance test."""
-
   test = power.Power
   page_set = page_sets.AndroidAcceptancePageSet
+  @classmethod
+  def Name(cls):
+    return 'power.android_acceptance'
+
 
 
 @benchmark.Enabled('android')
 class PowerTypical10Mobile(benchmark.Benchmark):
-
   """Android typical 10 mobile power test."""
-
   test = power.Power
   page_set = page_sets.Typical10MobilePageSet
+  @classmethod
+  def Name(cls):
+    return 'power.typical_10_mobile'
+
+