Fix an AppCacheStorageImpl leak in SiteInstanceTest.SiteInstanceDestructor by running the message l…

content/browser/site_instance_impl_unittest.cc

Index: content/browser/site_instance_impl_unittest.cc
===================================================================
--- content/browser/site_instance_impl_unittest.cc	(revision 154214)
+++ content/browser/site_instance_impl_unittest.cc	(working copy)
@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <string>
+#include <vector>
+
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/stl_util.h"
@@ -82,8 +85,7 @@
   }
 };
 
-class SiteInstanceTestBrowserClient :
-    public content::TestContentBrowserClient {
+class SiteInstanceTestBrowserClient : public content::TestContentBrowserClient {
  public:
   SiteInstanceTestBrowserClient()
       : privileged_process_id_(-1) {
@@ -135,6 +137,8 @@
 
     content::GetContentClient()->set_browser_for_testing(old_browser_client_);
     content::SetContentClient(old_client_);
+
+    DrainMessageLoops();

[awong, 2012/09/05 21:30:09]

This previously wasn't in TearDown() because the Browser itself was dead by this
point which meant we'd likely have a use-after-free.  Is there a particular test
that appcache is still active for?

[Lei Zhang, 2012/09/06 00:29:43]

I can tell you with this cl, there are no valgrind errors in these tests. I will
figure out which SiteInstanceTest triggers this leak.

   }
 
   void set_privileged_process_id(int process_id) {