Re-land a subset of r18520.

The original code review for this change was:
<http://codereview.chromium.org/125171>

The particular subset is the third bullet point in original description:

* Fix a bug where completion notification wasn't being sent when the response
was cached. (BUG=14188)

Note that the original was rolled-back because something was upsetting valgrind (BUG=14218).

Review URL: http://codereview.chromium.org/125227

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@18579 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 35 insertions, 14 deletions

diff --git a/net/base/host_resolver.cc b/net/base/host_resolver.cc
index 5a357eb..dd1ffcc 100644
--- a/net/base/host_resolver.cc
+++ b/net/base/host_resolver.cc
@@ -417,7 +417,12 @@ int HostResolver::Resolve(const RequestInfo& info,
         info.hostname(), base::TimeTicks::Now());
     if (cache_entry) {
       addresses->SetFrom(cache_entry->addrlist, info.port());
-      return OK;
+      int error = OK;
+
+      // Notify registered observers.
+      NotifyObserversFinishRequest(request_id, info, error);
+
+      return error;
     }
   }
 
diff --git a/net/base/host_resolver_unittest.cc b/net/base/host_resolver_unittest.cc
index 9c07c29..195b2fb 100644
--- a/net/base/host_resolver_unittest.cc
+++ b/net/base/host_resolver_unittest.cc
@@ -20,6 +20,7 @@
 #include "net/base/completion_callback.h"
 #include "net/base/host_resolver_unittest.h"
 #include "net/base/net_errors.h"
+#include "net/base/test_completion_callback.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using net::RuleBasedHostMapper;
@@ -757,25 +758,40 @@ TEST_F(HostResolverTest, Observers) {
 
   // Resolve "host1".
   net::HostResolver::RequestInfo info1("host1", 70);
-  host_resolver.Resolve(info1, &addrlist, NULL, NULL);
+  int rv = host_resolver.Resolve(info1, &addrlist, NULL, NULL);
+  EXPECT_EQ(net::OK, rv);
 
   EXPECT_EQ(1U, observer.start_log.size());
   EXPECT_EQ(1U, observer.finish_log.size());
-  EXPECT_TRUE(
-      observer.start_log[0] == CapturingObserver::StartEntry(0, info1));
-  EXPECT_TRUE(
-      observer.finish_log[0] == CapturingObserver::FinishEntry(0, true, info1));
+  EXPECT_TRUE(observer.start_log[0] ==
+              CapturingObserver::StartEntry(0, info1));
+  EXPECT_TRUE(observer.finish_log[0] ==
+              CapturingObserver::FinishEntry(0, true, info1));
+
+  // Resolve "host1" again -- this time it  will be served from cache, but it
+  // should still notify of completion.
+  TestCompletionCallback callback;
+  rv = host_resolver.Resolve(info1, &addrlist, &callback, NULL);
+  ASSERT_EQ(net::OK, rv);  // Should complete synchronously.
+
+  EXPECT_EQ(2U, observer.start_log.size());
+  EXPECT_EQ(2U, observer.finish_log.size());
+  EXPECT_TRUE(observer.start_log[1] ==
+              CapturingObserver::StartEntry(1, info1));
+  EXPECT_TRUE(observer.finish_log[1] ==
+              CapturingObserver::FinishEntry(1, true, info1));
 
   // Resolve "host2", setting referrer to "http://foobar.com"
   net::HostResolver::RequestInfo info2("host2", 70);
   info2.set_referrer(GURL("http://foobar.com"));
-  host_resolver.Resolve(info2, &addrlist, NULL, NULL);
+  rv = host_resolver.Resolve(info2, &addrlist, NULL, NULL);
+  EXPECT_EQ(net::OK, rv);
 
-  EXPECT_EQ(2U, observer.start_log.size());
-  EXPECT_EQ(2U, observer.finish_log.size());
-  EXPECT_TRUE(observer.start_log[1] == CapturingObserver::StartEntry(1, info2));
-  EXPECT_TRUE(observer.finish_log[1] == CapturingObserver::FinishEntry(
-      1, true, info2));
+  EXPECT_EQ(3U, observer.start_log.size());
+  EXPECT_EQ(3U, observer.finish_log.size());
+  EXPECT_TRUE(observer.start_log[2] == CapturingObserver::StartEntry(2, info2));
+  EXPECT_TRUE(observer.finish_log[2] ==
+              CapturingObserver::FinishEntry(2, true, info2));
 
   // Unregister the observer.
   host_resolver.RemoveObserver(&observer);
@@ -785,8 +801,8 @@ TEST_F(HostResolverTest, Observers) {
   host_resolver.Resolve(info3, &addrlist, NULL, NULL);
 
   // No effect this time, since observer was removed.
-  EXPECT_EQ(2U, observer.start_log.size());
-  EXPECT_EQ(2U, observer.finish_log.size());
+  EXPECT_EQ(3U, observer.start_log.size());
+  EXPECT_EQ(3U, observer.finish_log.size());
 }
 
 }  // namespace