Report Precache.TimeSinceLastPrecache

components/precache/core/precache_session_table_unittest.cc

Index: components/precache/core/precache_session_table_unittest.cc
diff --git a/components/precache/core/precache_session_table_unittest.cc b/components/precache/core/precache_session_table_unittest.cc
index c0d37d502730e7523d430121f2d58e97e72e934b..9302a166343d92659c44e1f3e94fb6d027ba96a0 100644
--- a/components/precache/core/precache_session_table_unittest.cc
+++ b/components/precache/core/precache_session_table_unittest.cc
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <stdint.h>
+
 #include "base/compiler_specific.h"
 #include "base/time/time.h"
 #include "components/precache/core/precache_session_table.h"
@@ -31,6 +33,33 @@ class PrecacheSessionTableTest : public testing::Test {
   std::unique_ptr<sql::Connection> db_;
 };
 
+TEST_F(PrecacheSessionTableTest, LastPrecacheTimestamp) {
+  const base::Time sometime = base::Time::FromDoubleT(42);
+
+  precache_session_table_->SetLastPrecacheTimestamp(sometime);
+
+  EXPECT_EQ(sometime, precache_session_table_->GetLastPrecacheTimestamp());
+
+  precache_session_table_->DeleteLastPrecacheTimestamp();
+
+  EXPECT_EQ(base::Time(), precache_session_table_->GetLastPrecacheTimestamp());
+}
+
+TEST_F(PrecacheSessionTableTest, LastPrecacheTimestampSaturatedInt64) {
+  // If I merely add 1 it won't change the double due to the lack of resolution:
+  // 63 bits of int64 vs 55 of double.
+  const double beyond_int64_seconds =
+      static_cast<double>(std::numeric_limits<int64_t>::max()) * 2;
+  const base::Time large_time = base::Time::FromDoubleT(beyond_int64_seconds);
+
+  precache_session_table_->SetLastPrecacheTimestamp(large_time);
+
+  EXPECT_EQ(large_time, precache_session_table_->GetLastPrecacheTimestamp());
+  // Anyway, base::Time does int64_t saturation for us, so these saturated casts
+  // are not strictly needed with the current implementation of base::Time.
+  EXPECT_TRUE(large_time.is_max());
+}
+
 TEST_F(PrecacheSessionTableTest, SaveAndGetUnfinishedWork) {
   std::unique_ptr<PrecacheUnfinishedWork> unfinished_work(
       new PrecacheUnfinishedWork());