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

tools/perf/benchmarks/task_execution_time.py

Index: tools/perf/benchmarks/task_execution_time.py
diff --git a/tools/perf/benchmarks/task_execution_time.py b/tools/perf/benchmarks/task_execution_time.py
index eea42dc3b202ff2899449ed6671d5aff1eedaa13..7fd2617ad7180fc3294b9ac29c7ddbdac59666a9 100644
--- a/tools/perf/benchmarks/task_execution_time.py
+++ b/tools/perf/benchmarks/task_execution_time.py
@@ -14,6 +14,10 @@ class TaskExecutionTimeKeyMobileSites(benchmark.Benchmark):
   test = task_execution_time.TaskExecutionTime
   page_set = page_sets.KeyMobileSitesSmoothPageSet
 
+  @classmethod
+  def Name(cls):
+    return 'task_execution_time.key_mobile_sites_smooth'
+
 
 @benchmark.Enabled('android')
 class TaskExecutionTimeToughSchedulingCases(benchmark.Benchmark):
@@ -21,3 +25,7 @@ class TaskExecutionTimeToughSchedulingCases(benchmark.Benchmark):
   http://www.chromium.org/developers/design-documents/rendering-benchmarks"""
   test = task_execution_time.TaskExecutionTime
   page_set = page_sets.ToughSchedulingCasesPageSet
+  @classmethod
+  def Name(cls):
+    return 'task_execution_time.tough_scheduling_cases'
+