Clear the host cache when closing the last incognito window.

This avoids retaining navigation history relating to the incognito window.

I piggy-back off of the dns prefetcher's OffTheRecordObserver to do this. In the future I hope to have a separate host resolver for off the record mode, so this won't be necessary.

BUG=24629

Review URL: http://codereview.chromium.org/523076

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@35923 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 25 insertions, 0 deletions

diff --git a/net/base/host_cache.h b/net/base/host_cache.h
index 4eb5853..c13c6a0 100644
--- a/net/base/host_cache.h
+++ b/net/base/host_cache.h
@@ -79,6 +79,11 @@ class HostCache {
              const AddressList addrlist,
              base::TimeTicks now);
 
+  // Empties the cache.
+  void clear() {
+    entries_.clear();
+  }
+
   // Returns true if this HostCache can contain no entries.
   bool caching_is_disabled() const {
     return max_entries_ == 0;
diff --git a/net/base/host_cache_unittest.cc b/net/base/host_cache_unittest.cc
index 5f4e21b..141cfde 100644
--- a/net/base/host_cache_unittest.cc
+++ b/net/base/host_cache_unittest.cc
@@ -319,6 +319,26 @@ TEST(HostCacheTest, NoCache) {
   EXPECT_EQ(0U, cache.size());
 }
 
+TEST(HostCacheTest, Clear) {
+  HostCache cache(kMaxCacheEntries, kSuccessEntryTTL, kFailureEntryTTL);
+
+  // Set t=0.
+  base::TimeTicks now;
+
+  EXPECT_EQ(0u, cache.size());
+
+  // Add three entries.
+  cache.Set(Key("foobar1.com"), OK, AddressList(), now);
+  cache.Set(Key("foobar2.com"), OK, AddressList(), now);
+  cache.Set(Key("foobar3.com"), OK, AddressList(), now);
+
+  EXPECT_EQ(3u, cache.size());
+
+  cache.clear();
+
+  EXPECT_EQ(0u, cache.size());
+}
+
 // Tests the less than and equal operators for HostCache::Key work.
 TEST(HostCacheTest, KeyComparators) {
   struct {