Optimize phishing page term feature extraction.

We've been seeing in the histograms that for some users, page feature
extraction is taking much longer than we would like, up to 200ms between
stops. This could possibly contribute to jankiness in the UI. These are some
timings from my desktop for how long it takes to extract features before and
after these changes. Obviously this is on much better hardware than the use case
we are worried about, but hopefully the increase is speed is proportional.

           Before  After
CNN        19       7.5    
ESPN       22       9.5
Google     12       4
Salon      40       12

BUG=
TEST=Ran associated unit tests.


Review URL: http://codereview.chromium.org/7549003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@96097 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 18 insertions, 0 deletions

diff --git a/base/memory/mru_cache_unittest.cc b/base/memory/mru_cache_unittest.cc
index 89ca2fa..39677f2 100644
--- a/base/memory/mru_cache_unittest.cc
+++ b/base/memory/mru_cache_unittest.cc
@@ -251,3 +251,21 @@ TEST(MRUCacheTest, AutoEvict) {
   // There should be no objects leaked.
   EXPECT_EQ(initial_count, cached_item_live_count);
 }
+
+TEST(MRUCacheTest, HashingMRUCache) {
+  // Very simple test to make sure that the hashing cache works correctly.
+  typedef base::HashingMRUCache<std::string, CachedItem> Cache;
+  Cache cache(Cache::NO_AUTO_EVICT);
+
+  CachedItem one(1);
+  cache.Put("First", one);
+
+  CachedItem two(2);
+  cache.Put("Second", two);
+
+  EXPECT_EQ(one.value, cache.Get("First")->second.value);
+  EXPECT_EQ(two.value, cache.Get("Second")->second.value);
+  cache.ShrinkToSize(1);
+  EXPECT_EQ(two.value, cache.Get("Second")->second.value);
+  EXPECT_EQ(cache.end(), cache.Get("First"));
+}