Match only prefixes of histogram names.

base/test/histogram_tester_unittest.cc

Index: base/test/histogram_tester_unittest.cc
diff --git a/base/test/histogram_tester_unittest.cc b/base/test/histogram_tester_unittest.cc
index f896eaa3e89357abda627fee1d2f9d4b9fb52c0e..e49ed97ac10d7842636348d91d2a908ace92483b 100644
--- a/base/test/histogram_tester_unittest.cc
+++ b/base/test/histogram_tester_unittest.cc
@@ -21,7 +21,6 @@ const char kHistogram2[] = "Test2";
 const char kHistogram3[] = "Test3";
 const char kHistogram4[] = "Test4";
 const char kHistogram5[] = "Test5";
-const char kHistogramSuffix[] = "Test4.Test5";
 
 }  // namespace
 
@@ -118,12 +117,14 @@ TEST_F(HistogramTesterTest, TestGetAllSamples_NoSamples) {
   EXPECT_THAT(tester.GetAllSamples(kHistogram5), IsEmpty());
 }
 
-// Wrong behaviour for GetTotalCountForPrefix: https://crbug.com/659977
-TEST_F(HistogramTesterTest, DISABLED_TestGetTotalCountsForPrefix) {
+TEST_F(HistogramTesterTest, TestGetTotalCountsForPrefix) {
   HistogramTester tester;
-  UMA_HISTOGRAM_ENUMERATION(kHistogramSuffix, 2, 5);
+  UMA_HISTOGRAM_ENUMERATION("Test1.Test2.Test3", 2, 5);
 
-  EXPECT_TRUE(tester.GetTotalCountsForPrefix("Test5").empty());
+  // Regression check for bug https://crbug.com/659977.
+  EXPECT_TRUE(tester.GetTotalCountsForPrefix("Test2.").empty());
+
+  EXPECT_EQ(1u, tester.GetTotalCountsForPrefix("Test1.").size());
 }
 
 }  // namespace base