Adds TTL argument to HostCache::Set.

net/base/mock_host_resolver.cc

Index: net/base/mock_host_resolver.cc
diff --git a/net/base/mock_host_resolver.cc b/net/base/mock_host_resolver.cc
index 612c6007a48d1f076ee3058552c04ebb498e841d..49ef2c851108649007c798f5a8f64832c8bbb59b 100644
--- a/net/base/mock_host_resolver.cc
+++ b/net/base/mock_host_resolver.cc
@@ -22,6 +22,11 @@ namespace net {
 
 namespace {
 
+// Cache size for the MockCachingHostResolver.
+const unsigned kMaxCacheEntries = 100;
+// TTL for the successful resolutions. Failures are not cached.
+const unsigned kCacheEntryTTLSeconds = 60;
+
 char* do_strdup(const char* src) {
 #if defined(OS_WIN)
   return _strdup(src);
@@ -130,10 +135,7 @@ MockHostResolverBase::MockHostResolverBase(bool use_caching)
   proc_ = rules_;
 
   if (use_caching) {
-    cache_.reset(new HostCache(
-        100,  // max entries.
-        base::TimeDelta::FromMinutes(1),
-        base::TimeDelta::FromSeconds(0)));
+    cache_.reset(new HostCache(kMaxCacheEntries));
   }
 }
 
@@ -173,7 +175,11 @@ int MockHostResolverBase::ResolveProc(size_t id,
     HostCache::Key key(info.hostname(),
                        info.address_family(),
                        info.host_resolver_flags());
-    cache_->Set(key, rv, addr, base::TimeTicks::Now());
+    // Storing a failure with TTL 0 so that it overwrites previous value.
+    base::TimeDelta ttl;
+    if (rv == OK)
+      ttl = base::TimeDelta::FromSeconds(kCacheEntryTTLSeconds);
+    cache_->Set(key, rv, addr, base::TimeTicks::Now(), ttl);
   }
   if (rv == OK)
     *addresses = CreateAddressListUsingPort(addr, info.port());