net/disk_cache/simple: Remove launched base::Feature.

kSimpleCacheEvictionWithSize was launched in M63, time to remove the
feature from the codebase :).

Bug: 736437
Change-Id: I7e1ffd378a011eca0c414ccf712e9aceb4297704
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2066897Reviewed-by: Maksim Orlovich <morlovich@chromium.org>
Commit-Queue: Benoit L <lizeb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#743148}

net/disk_cache/simple/simple_index.cc

@@ -13,7 +13,6 @@
 #include "base/bind_helpers.h"
 #include "base/files/file_util.h"
 #include "base/logging.h"
-#include "base/metrics/field_trial.h"
 #include "base/numerics/safe_conversions.h"
 #include "base/pickle.h"
 #include "base/strings/string_number_conversions.h"
@@ -59,9 +58,6 @@ static const int kEstimatedEntryOverhead = 512;
 
 namespace disk_cache {
 
-const base::Feature kSimpleCacheEvictionWithSize = {
-    "SimpleCacheEvictionWithSize", base::FEATURE_ENABLED_BY_DEFAULT};
-
 EntryMetadata::EntryMetadata()
     : last_used_time_seconds_since_epoch_(0),
       entry_size_256b_chunks_(0),
@@ -426,15 +422,14 @@ void SimpleIndex::StartEvictionIfNeeded() {
   std::vector<std::pair<uint64_t, const EntrySet::value_type*>> entries;
   entries.reserve(entries_set_.size());
   uint32_t now = (base::Time::Now() - base::Time::UnixEpoch()).InSeconds();
-  bool use_size = base::FeatureList::IsEnabled(kSimpleCacheEvictionWithSize);
   for (EntrySet::const_iterator i = entries_set_.begin();
        i != entries_set_.end(); ++i) {
     uint64_t sort_value = now - i->second.RawTimeForSorting();
-    if (use_size) {
-      // Will not overflow since we're multiplying two 32-bit values and storing
-      // them in a 64-bit variable.
-      sort_value *= i->second.GetEntrySize() + kEstimatedEntryOverhead;
-    }
+    // See crbug.com/736437 for context.
+    //
+    // Will not overflow since we're multiplying two 32-bit values and storing
+    // them in a 64-bit variable.
+    sort_value *= i->second.GetEntrySize() + kEstimatedEntryOverhead;
     // Subtract so we don't need a custom comparator.
     entries.emplace_back(std::numeric_limits<uint64_t>::max() - sort_value,
                          &*i);

net/disk_cache/simple/simple_index.h

@@ -14,7 +14,6 @@
 #include <vector>
 
 #include "base/callback.h"
-#include "base/feature_list.h"
 #include "base/files/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
@@ -46,8 +45,6 @@ class SimpleIndexDelegate;
 class SimpleIndexFile;
 struct SimpleIndexLoadResult;
 
-NET_EXPORT_PRIVATE extern const base::Feature kSimpleCacheEvictionWithSize;
-
 class NET_EXPORT_PRIVATE EntryMetadata {
  public:
   EntryMetadata();

net/disk_cache/simple/simple_index_unittest.cc

@@ -13,13 +13,10 @@
 #include "base/files/scoped_temp_dir.h"
 #include "base/hash/hash.h"
 #include "base/logging.h"
-#include "base/metrics/field_trial.h"
-#include "base/metrics/field_trial_param_associator.h"
 #include "base/pickle.h"
 #include "base/strings/stringprintf.h"
 #include "base/task_runner.h"
 #include "base/test/mock_entropy_provider.h"
-#include "base/test/scoped_feature_list.h"
 #include "base/threading/platform_thread.h"
 #include "base/time/time.h"
 #include "net/base/cache_type.h"
@@ -180,9 +177,6 @@ class SimpleIndexTest : public net::TestWithTaskEnvironment,
   std::unique_ptr<SimpleIndex> index_;
   base::WeakPtr<MockSimpleIndexFile> index_file_;
 
-  std::unique_ptr<base::FieldTrialList> field_trial_list_;
-  base::test::ScopedFeatureList scoped_feature_list_;
-
   std::vector<uint64_t> last_doom_entry_hashes_;
   int doom_entries_calls_ = 0;
 };
@@ -609,40 +603,6 @@ TEST_F(SimpleIndexTest, BasicEviction) {
   ASSERT_EQ(2u, last_doom_entry_hashes().size());
 }
 
-TEST_F(SimpleIndexTest, EvictByLRU) {
-  base::test::ScopedFeatureList features;
-  features.InitAndDisableFeature(kSimpleCacheEvictionWithSize);
-
-  base::Time now(base::Time::Now());
-  index()->SetMaxSize(50000);
-  InsertIntoIndexFileReturn(hashes_.at<1>(), now - base::TimeDelta::FromDays(2),
-                            475u);
-  InsertIntoIndexFileReturn(hashes_.at<2>(), now - base::TimeDelta::FromDays(1),
-                            40000u);
-  ReturnIndexFile();
-  WaitForTimeChange();
-
-  index()->Insert(hashes_.at<3>());
-  // Confirm index is as expected: No eviction, everything there.
-  EXPECT_EQ(3, index()->GetEntryCount());
-  EXPECT_EQ(0, doom_entries_calls());
-  EXPECT_TRUE(index()->Has(hashes_.at<1>()));
-  EXPECT_TRUE(index()->Has(hashes_.at<2>()));
-  EXPECT_TRUE(index()->Has(hashes_.at<3>()));
-
-  // Trigger an eviction, and make sure the right things are tossed.
-  // TODO(morlovich): This is dependent on the innards of the implementation
-  // as to at exactly what point we trigger eviction. Not sure how to fix
-  // that.
-  index()->UpdateEntrySize(hashes_.at<3>(), 40000u);
-  EXPECT_EQ(1, doom_entries_calls());
-  EXPECT_EQ(1, index()->GetEntryCount());
-  EXPECT_FALSE(index()->Has(hashes_.at<1>()));
-  EXPECT_FALSE(index()->Has(hashes_.at<2>()));
-  EXPECT_TRUE(index()->Has(hashes_.at<3>()));
-  ASSERT_EQ(2u, last_doom_entry_hashes().size());
-}
-
 TEST_F(SimpleIndexTest, EvictBySize) {
   base::Time now(base::Time::Now());
   index()->SetMaxSize(50000);