Use saturated_cast<> instead of checked_cast<> for converting

net/disk_cache/simple/simple_index_unittest.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/disk_cache/simple/simple_index.h"
 
 #include <algorithm>
 #include <functional>
 #include <memory>
 #include <utility>
@@ skipping 16 matching lines @@
 
 namespace disk_cache {
 namespace {
 
 const base::Time kTestLastUsedTime =
     base::Time::UnixEpoch() + base::TimeDelta::FromDays(20);
 const uint64_t kTestEntrySize = 789;
 
 }  // namespace
 
-
-class EntryMetadataTest  : public testing::Test {
+class EntryMetadataTest : public testing::Test {
  public:
   EntryMetadata NewEntryMetadataWithValues() {
     return EntryMetadata(kTestLastUsedTime, kTestEntrySize);
   }
 
   void CheckEntryMetadataValues(const EntryMetadata& entry_metadata) {
     EXPECT_LT(kTestLastUsedTime - base::TimeDelta::FromSeconds(2),
               entry_metadata.GetLastUsedTime());
     EXPECT_GT(kTestLastUsedTime + base::TimeDelta::FromSeconds(2),
               entry_metadata.GetLastUsedTime());
@@ skipping 130 matching lines @@
 
   const base::Time new_time = base::Time::Now();
   entry_metadata.SetLastUsedTime(new_time);
 
   EXPECT_LT(new_time - base::TimeDelta::FromSeconds(2),
             entry_metadata.GetLastUsedTime());
   EXPECT_GT(new_time + base::TimeDelta::FromSeconds(2),
             entry_metadata.GetLastUsedTime());
 }
 
+// Tests that setting an unusually small/large last used time results in
+// truncation (rather than crashing).
+TEST_F(EntryMetadataTest, SaturatedLastUsedTime) {
+  EntryMetadata entry_metadata;
+
+  // Set a time that is too large to be represented internally as 32-bit unix
+  // timestamp. Will saturate to a large timestamp (in year 2106).
+  entry_metadata.SetLastUsedTime(base::Time::Max());
+  EXPECT_EQ(INT64_C(15939440895000000),
+            entry_metadata.GetLastUsedTime().ToInternalValue());
+
+  // Set a time that is too small to be represented by a unix timestamp (before
+  // 1970).
+  entry_metadata.SetLastUsedTime(
+      base::Time::FromInternalValue(7u));  // This is a date in 1601.
+  EXPECT_EQ(base::Time::UnixEpoch() + base::TimeDelta::FromSeconds(1),
+            entry_metadata.GetLastUsedTime());
+}
+
 TEST_F(EntryMetadataTest, Serialize) {
   EntryMetadata entry_metadata = NewEntryMetadataWithValues();
 
   base::Pickle pickle;
   entry_metadata.Serialize(&pickle);
 
   base::PickleIterator it(pickle);
   EntryMetadata new_entry_metadata;
   new_entry_metadata.Deserialize(&it);
   CheckEntryMetadataValues(new_entry_metadata);
@@ skipping 421 matching lines @@
   WaitForTimeChange();
   EXPECT_EQ(expected_trigger, index()->write_to_disk_timer_.desired_run_time());
   index()->Insert(hashes_.at<2>());
   index()->UpdateEntrySize(hashes_.at<2>(), 40);
   EXPECT_TRUE(index()->write_to_disk_timer_.IsRunning());
   EXPECT_LT(expected_trigger, index()->write_to_disk_timer_.desired_run_time());
   index()->write_to_disk_timer_.Stop();
 }
 
 }  // namespace disk_cache