Add Quota.TimeSinceOriginEvicted UMA histogram.

content/browser/quota/quota_manager_unittest.cc

Index: content/browser/quota/quota_manager_unittest.cc
diff --git a/content/browser/quota/quota_manager_unittest.cc b/content/browser/quota/quota_manager_unittest.cc
index 56cfba41cea29d2d64c457d11e4e2d5f37fe6455..b316648ae15f08009b5b0427fff5d2384376b7df 100644
--- a/content/browser/quota/quota_manager_unittest.cc
+++ b/content/browser/quota/quota_manager_unittest.cc
@@ -15,6 +15,7 @@
 #include "base/run_loop.h"
 #include "base/stl_util.h"
 #include "base/sys_info.h"
+#include "base/test/histogram_tester.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "content/public/test/mock_special_storage_policy.h"
@@ -291,7 +292,7 @@ class QuotaManagerTest : public testing::Test {
   }
 
   void DeleteOriginFromDatabase(const GURL& origin, StorageType type) {
-    quota_manager_->DeleteOriginFromDatabase(origin, type);
+    quota_manager_->DeleteOriginFromDatabase(origin, type, false);
   }
 
   void GetEvictionOrigin(StorageType type) {
@@ -1358,6 +1359,51 @@ TEST_F(QuotaManagerTest, EvictOriginData) {
   EXPECT_EQ(predelete_host_pers, usage());
 }
 
+TEST_F(QuotaManagerTest, EvictOriginDataHistogram) {
+  const GURL kOrigin = GURL("http://foo.com");
+  static const MockOriginData kData[] = {
+      {"http://foo.com/", kTemp, 1},
+  };
+
+  base::HistogramTester histograms;
+  MockStorageClient* client =
+      CreateClient(kData, arraysize(kData), QuotaClient::kFileSystem);
+  RegisterClient(client);
+
+  GetGlobalUsage(kTemp);
+  base::RunLoop().RunUntilIdle();
+
+  EvictOriginData(GURL("http://foo.com/"), kTemp);
+  base::RunLoop().RunUntilIdle();
+
+  // First eviction has no 'last' time to compare to.
+  histograms.ExpectTotalCount(
+      QuotaManager::kTimeBetweenRepeatedOriginEvictionsHistogram, 0);
+
+  client->AddOriginAndNotify(GURL("http://foo.com"), kTemp, 100);
+
+  GetGlobalUsage(kTemp);
+  base::RunLoop().RunUntilIdle();
+
+  EvictOriginData(GURL("http://foo.com/"), kTemp);
+  base::RunLoop().RunUntilIdle();
+
+  // Second eviction should log a histogram sample.
+  histograms.ExpectTotalCount(
+      QuotaManager::kTimeBetweenRepeatedOriginEvictionsHistogram, 1);
+
+  client->AddOriginAndNotify(GURL("http://foo.com"), kTemp, 100);
+
+  GetGlobalUsage(kTemp);
+  base::RunLoop().RunUntilIdle();
+
+  DeleteOriginFromDatabase(GURL("http://foo.com"), kTemp);
+
+  // Deletion from non-eviction source should not log a histogram sample.
+  histograms.ExpectTotalCount(
+      QuotaManager::kTimeBetweenRepeatedOriginEvictionsHistogram, 1);
+}
+
 TEST_F(QuotaManagerTest, EvictOriginDataWithDeletionError) {
   static const MockOriginData kData[] = {
     { "http://foo.com/",   kTemp,       1 },