Add shared memory cleanup before/after all tests

base/metrics/stats_table_unittest.cc

Index: base/metrics/stats_table_unittest.cc
===================================================================
--- base/metrics/stats_table_unittest.cc	(revision 140808)
+++ base/metrics/stats_table_unittest.cc	(working copy)
@@ -312,6 +312,7 @@
   const std::string kTableName = "StatTable";
   const int kMaxThreads = 20;
   const int kMaxCounter = 5;
+  DeleteShmem(kTableName);
   StatsTable table(kTableName, kMaxThreads, kMaxCounter);
   StatsTable::set_current(&table);
 
@@ -337,15 +338,16 @@
   bar.Stop();
   EXPECT_GT(table.GetCounterValue("t:bar"), 0);
   EXPECT_LE(kDuration.InMilliseconds() * 2, table.GetCounterValue("t:bar"));
+  DeleteShmem(kTableName);
 }
 
 // Test some basic StatsRate operations
-// Usually fails on all platforms when run alone. http://crbug.com/131024
-TEST_F(StatsTableTest, DISABLED_StatsRate) {
+TEST_F(StatsTableTest, StatsRate) {
   // Create a stats table.
   const std::string kTableName = "StatTable";
   const int kMaxThreads = 20;
   const int kMaxCounter = 5;
+  DeleteShmem(kTableName);
   StatsTable table(kTableName, kMaxThreads, kMaxCounter);
   StatsTable::set_current(&table);
 
@@ -371,6 +373,7 @@
   baz.Stop();
   EXPECT_EQ(2, table.GetCounterValue("c:baz"));
   EXPECT_LE(kDuration.InMilliseconds() * 2, table.GetCounterValue("t:baz"));
+  DeleteShmem(kTableName);
 }
 
 // Test some basic StatsScope operations