Implementation of application cache update algorithm.

Does not include storage nor processing of pending master entries.


TEST=verify update functionality
BUG=none
Review URL: http://codereview.chromium.org/201070

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@28123 0039d316-1c4b-4281-b951-d872f2087c98

34 files changed, 2258 insertions, 28 deletions

diff --git a/webkit/appcache/appcache.cc b/webkit/appcache/appcache.cc
index 5e7bca63..450f978 100644
--- a/webkit/appcache/appcache.cc
+++ b/webkit/appcache/appcache.cc
@@ -7,17 +7,17 @@
 #include "base/logging.h"
 #include "webkit/appcache/appcache_group.h"
 #include "webkit/appcache/appcache_host.h"
+#include "webkit/appcache/appcache_interfaces.h"
 #include "webkit/appcache/appcache_service.h"
 
 namespace appcache {
 
 AppCache::AppCache(AppCacheService *service, int64 cache_id)
-  : cache_id_(cache_id),
-    manifest_(NULL),
-    owning_group_(NULL),
-    online_whitelist_all_(false),
-    is_complete_(false),
-    service_(service) {
+    : cache_id_(cache_id),
+      owning_group_(NULL),
+      online_whitelist_all_(false),
+      is_complete_(false),
+      service_(service) {
   service_->AddCache(this);
 }
 
@@ -42,7 +42,7 @@ void AppCache::AddEntry(const GURL& url, const AppCacheEntry& entry) {
 
 void AppCache::AddOrModifyEntry(const GURL& url, const AppCacheEntry& entry) {
   std::pair<EntryMap::iterator, bool> ret =
-    entries_.insert(EntryMap::value_type(url, entry));
+      entries_.insert(EntryMap::value_type(url, entry));
 
   // Entry already exists.  Merge the types of the new and existing entries.
   if (!ret.second)
@@ -54,4 +54,11 @@ AppCacheEntry* AppCache::GetEntry(const GURL& url) {
   return (it != entries_.end()) ? &(it->second) : NULL;
 }
 
+void AppCache::InitializeWithManifest(Manifest* manifest) {
+  DCHECK(manifest);
+  fallback_namespaces_.swap(manifest->fallback_namespaces);
+  online_whitelist_namespaces_.swap(manifest->online_whitelist_namespaces);
+  online_whitelist_all_ = manifest->online_whitelist_all;
+}
+
 }  // namespace appcache
diff --git a/webkit/appcache/appcache.h b/webkit/appcache/appcache.h
index fcfa9d1..08fdd1b 100644
--- a/webkit/appcache/appcache.h
+++ b/webkit/appcache/appcache.h
@@ -13,6 +13,7 @@
 #include "base/ref_counted.h"
 #include "base/time.h"
 #include "googleurl/src/gurl.h"
+#include "testing/gtest/include/gtest/gtest_prod.h"
 #include "webkit/appcache/appcache_entry.h"
 #include "webkit/appcache/manifest_parser.h"
 
@@ -27,6 +28,8 @@ class AppCacheService;
 // cache is being created during an appcache upate.
 class AppCache : public base::RefCounted<AppCache> {
  public:
+  typedef std::map<GURL, AppCacheEntry> EntryMap;
+
   AppCache(AppCacheService *service, int64 cache_id);
   ~AppCache();
 
@@ -50,19 +53,27 @@ class AppCache : public base::RefCounted<AppCache> {
   // Do not store the returned object as it could be deleted anytime.
   AppCacheEntry* GetEntry(const GURL& url);
 
-  typedef std::map<GURL, AppCacheEntry> EntryMap;
   const EntryMap& entries() const { return entries_; }
 
+  const std::set<AppCacheHost*>& associated_hosts() const {
+    return associated_hosts_;
+  }
+
   bool IsNewerThan(AppCache* cache) const {
     return update_time_ > cache->update_time_;
   }
 
-  void set_update_time(base::TimeTicks ticks = base::TimeTicks::Now()) {
+  void set_update_time(base::TimeTicks ticks) {
     update_time_ = ticks;
   }
 
+  // Initializes the cache with information in the manifest.
+  // Do not use the manifest after this call.
+  void InitializeWithManifest(Manifest* manifest);
+
  private:
   friend class AppCacheHost;
+  friend class AppCacheUpdateJobTest;
 
   // Use AppCacheHost::AssociateCache() to manipulate host association.
   void AssociateHost(AppCacheHost* host) {
@@ -71,7 +82,6 @@ class AppCache : public base::RefCounted<AppCache> {
   void UnassociateHost(AppCacheHost* host);
 
   const int64 cache_id_;
-  AppCacheEntry* manifest_;  // also in entry map
   AppCacheGroup* owning_group_;
   std::set<AppCacheHost*> associated_hosts_;
 
@@ -88,6 +98,9 @@ class AppCache : public base::RefCounted<AppCache> {
 
   // to notify service when cache is deleted
   AppCacheService* service_;
+
+  FRIEND_TEST(AppCacheTest, InitializeWithManifest);
+  DISALLOW_COPY_AND_ASSIGN(AppCache);
 };
 
 }  // namespace appcache
diff --git a/webkit/appcache/appcache_group.cc b/webkit/appcache/appcache_group.cc
index 10307c2..67ca4cc 100644
--- a/webkit/appcache/appcache_group.cc
+++ b/webkit/appcache/appcache_group.cc
@@ -10,21 +10,24 @@
 #include "webkit/appcache/appcache.h"
 #include "webkit/appcache/appcache_host.h"
 #include "webkit/appcache/appcache_service.h"
+#include "webkit/appcache/appcache_update_job.h"
 
 namespace appcache {
 
 AppCacheGroup::AppCacheGroup(AppCacheService* service,
                              const GURL& manifest_url)
-  : manifest_url_(manifest_url),
-    update_status_(IDLE),
-    is_obsolete_(false),
-    newest_complete_cache_(NULL),
-    service_(service) {
+    : manifest_url_(manifest_url),
+      update_status_(IDLE),
+      is_obsolete_(false),
+      newest_complete_cache_(NULL),
+      update_job_(NULL),
+      service_(service) {
   service_->AddGroup(this);
 }
 
 AppCacheGroup::~AppCacheGroup() {
   DCHECK(old_caches_.empty());
+  DCHECK(!update_job_);
 
   // Newest complete cache might never have been associated with a host
   // and thus would not be cleaned up by the backend impl during shutdown.
@@ -34,6 +37,14 @@ AppCacheGroup::~AppCacheGroup() {
   service_->RemoveGroup(this);
 }
 
+void AppCacheGroup::AddObserver(Observer* observer) {
+  observers_.AddObserver(observer);
+}
+
+void AppCacheGroup::RemoveObserver(Observer* observer) {
+  observers_.RemoveObserver(observer);
+}
+
 void AppCacheGroup::AddCache(AppCache* complete_cache) {
   DCHECK(complete_cache->is_complete());
   if (!newest_complete_cache_) {
@@ -51,7 +62,6 @@ void AppCacheGroup::AddCache(AppCache* complete_cache) {
 
 bool AppCacheGroup::RemoveCache(AppCache* cache) {
   if (cache == newest_complete_cache_) {
-
     // Cannot remove newest cache if there are older caches as those may
     // eventually be swapped to the newest cache.
     if (!old_caches_.empty())
@@ -73,8 +83,27 @@ bool AppCacheGroup::RemoveCache(AppCache* cache) {
 }
 
 void AppCacheGroup::StartUpdateWithNewMasterEntry(
-    AppCacheHost* host, const GURL& master_entry_url) {
-  // TODO(michaeln): use the real AppCacheUpdateJob
+    AppCacheHost* host, const GURL& new_master_resource) {
+  /* TODO(jennb): enable after have logic for cancelling an update
+  if (!update_job_)
+    update_job_ = new AppCacheUpdateJob(service_, this);
+
+  update_job_->StartUpdate(host, new_master_resource);
+  */
+}
+
+void AppCacheGroup::SetUpdateStatus(UpdateStatus status) {
+  if (status == update_status_)
+    return;
+
+  update_status_ = status;
+
+  if (status != IDLE) {
+    DCHECK(update_job_);
+  } else {
+    update_job_ = NULL;
+    FOR_EACH_OBSERVER(Observer, observers_, OnUpdateComplete(this));
+  }
 }
 
 }  // namespace appcache
diff --git a/webkit/appcache/appcache_group.h b/webkit/appcache/appcache_group.h
index 20422ae..4230e8d 100644
--- a/webkit/appcache/appcache_group.h
+++ b/webkit/appcache/appcache_group.h
@@ -7,20 +7,30 @@
 
 #include <vector>
 
+#include "base/observer_list.h"
 #include "base/ref_counted.h"
 #include "googleurl/src/gurl.h"
+#include "testing/gtest/include/gtest/gtest_prod.h"
 
 namespace appcache {
 
 class AppCache;
 class AppCacheHost;
 class AppCacheService;
+class AppCacheUpdateJob;
 
 // Collection of application caches identified by the same manifest URL.
 // A group exists as long as it is in use by a host or is being updated.
 class AppCacheGroup : public base::RefCounted<AppCacheGroup> {
  public:
 
+  class Observer {
+    public:
+      // Called just after an appcache update has completed.
+      virtual void OnUpdateComplete(AppCacheGroup* group) = 0;
+      virtual ~Observer() { }
+  };
+
   enum UpdateStatus {
     IDLE,
     CHECKING,
@@ -30,10 +40,12 @@ class AppCacheGroup : public base::RefCounted<AppCacheGroup> {
   AppCacheGroup(AppCacheService* service, const GURL& manifest_url);
   ~AppCacheGroup();
 
-  const GURL& manifest_url() { return manifest_url_; }
+  // Adds/removes an observer, the AppCacheGroup does not take
+  // ownership of the observer.
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
 
-  UpdateStatus update_status() { return update_status_; }
-  void set_update_status(UpdateStatus status) { update_status_ = status; }
+  const GURL& manifest_url() { return manifest_url_; }
 
   bool is_obsolete() { return is_obsolete_; }
   void set_obsolete(bool value) { is_obsolete_ = value; }
@@ -46,6 +58,10 @@ class AppCacheGroup : public base::RefCounted<AppCacheGroup> {
   // cannot be removed as long as the group is still in use.
   bool RemoveCache(AppCache* cache);
 
+  bool HasCache() { return newest_complete_cache_ || !old_caches_.empty(); }
+
+  UpdateStatus update_status() { return update_status_; }
+
   // Starts an update via update() javascript API.
   void StartUpdate() {
     StartUpdateWithHost(NULL);
@@ -63,19 +79,39 @@ class AppCacheGroup : public base::RefCounted<AppCacheGroup> {
                                      const GURL& new_master_resource);
 
  private:
+  friend class AppCacheUpdateJob;
+  friend class AppCacheUpdateJobTest;
+
+  typedef std::vector<scoped_refptr<AppCache> > Caches;
+
+  AppCacheUpdateJob* update_job() { return update_job_; }
+  void SetUpdateStatus(UpdateStatus status);
+
+  const Caches& old_caches() { return old_caches_; }
+
   GURL manifest_url_;
   UpdateStatus update_status_;
   bool is_obsolete_;
 
-  // old complete app caches
-  typedef std::vector<scoped_refptr<AppCache> > Caches;
+  // Old complete app caches.
   Caches old_caches_;
 
-  // newest cache in this group to be complete, aka relevant cache
+  // Newest cache in this group to be complete, aka relevant cache.
   scoped_refptr<AppCache> newest_complete_cache_;
 
-  // to notify service when group is no longer needed
+  // Current update job for this group, if any.
+  AppCacheUpdateJob* update_job_;
+
+  // Central service object.
   AppCacheService* service_;
+
+  // List of objects observing this group.
+  ObserverList<Observer> observers_;
+
+  FRIEND_TEST(AppCacheGroupTest, StartUpdate);
+  FRIEND_TEST(AppCacheUpdateJobTest, AlreadyChecking);
+  FRIEND_TEST(AppCacheUpdateJobTest, AlreadyDownloading);
+  DISALLOW_COPY_AND_ASSIGN(AppCacheGroup);
 };
 
 }  // namespace appcache
diff --git a/webkit/appcache/appcache_group_unittest.cc b/webkit/appcache/appcache_group_unittest.cc
index bcfbce0..74846af 100644
--- a/webkit/appcache/appcache_group_unittest.cc
+++ b/webkit/appcache/appcache_group_unittest.cc
@@ -7,6 +7,7 @@
 #include "webkit/appcache/appcache_group.h"
 #include "webkit/appcache/appcache_host.h"
 #include "webkit/appcache/appcache_service.h"
+#include "webkit/appcache/appcache_update_job.h"
 
 namespace {
 
@@ -130,4 +131,27 @@ TEST(AppCacheGroupTest, CleanupUnusedGroup) {
   EXPECT_EQ(frontend.last_status_, appcache::UNCACHED);
 }
 
+TEST(AppCacheGroupTest, StartUpdate) {
+  /* TODO(jennb) - uncomment after AppCacheGroup::StartUpdate does something.
+  AppCacheService service;
+  scoped_refptr<AppCacheGroup> group =
+      new AppCacheGroup(&service, GURL("http://foo.com"));
+
+  // Set state to checking to prevent update job from executing fetches.
+  group->update_status_ = AppCacheGroup::CHECKING;
+  group->StartUpdate();
+  AppCacheUpdateJob* update = group->update_job_;
+  EXPECT_TRUE(update != NULL);
+
+  // Start another update, check that same update job is in use.
+  group->StartUpdateWithHost(NULL);
+  EXPECT_EQ(update, group->update_job_);
+
+  // Remove update job's reference to this group.
+  delete update;
+  EXPECT_TRUE(group->update_job_ == NULL);
+  EXPECT_EQ(AppCacheGroup::IDLE, group->update_status());
+  */
+}
+
 }  // namespace appcache
diff --git a/webkit/appcache/appcache_interfaces.cc b/webkit/appcache/appcache_interfaces.cc
index 30bb208..5b24597 100644
--- a/webkit/appcache/appcache_interfaces.cc
+++ b/webkit/appcache/appcache_interfaces.cc
@@ -12,6 +12,8 @@ using WebKit::WebApplicationCacheHost;
 
 namespace appcache {
 
+const char kManifestMimeType[] = "text/cache-manifest";
+
 const char kHttpScheme[] = "http";
 const char kHttpsScheme[] = "https";
 const char kHttpGETMethod[] = "GET";
diff --git a/webkit/appcache/appcache_interfaces.h b/webkit/appcache/appcache_interfaces.h
index db38bcd..fcba1d8 100644
--- a/webkit/appcache/appcache_interfaces.h
+++ b/webkit/appcache/appcache_interfaces.h
@@ -16,6 +16,7 @@ namespace appcache {
 
 // Defines constants, types, and abstract classes used in the main
 // process and in child processes.
+extern const char kManifestMimeType[];
 
 static const int kNoHostId = 0;
 static const int64 kNoCacheId = 0;
diff --git a/webkit/appcache/appcache_service.cc b/webkit/appcache/appcache_service.cc
index e524c62..c36ad1e 100644
--- a/webkit/appcache/appcache_service.cc
+++ b/webkit/appcache/appcache_service.cc
@@ -61,6 +61,8 @@ void AppCacheService::AddGroup(AppCacheGroup* group) {
 
 void AppCacheService::RemoveGroup(AppCacheGroup* group) {
   groups_.erase(group->manifest_url());
+
+  // TODO(jennb): if group is obsolete, delete from storage.
 }
 
 void AppCacheService::LoadCache(int64 id, LoadClient* client) {
diff --git a/webkit/appcache/appcache_service.h b/webkit/appcache/appcache_service.h
index 9a504d9..4dff28e 100644
--- a/webkit/appcache/appcache_service.h
+++ b/webkit/appcache/appcache_service.h
@@ -53,8 +53,6 @@ class AppCacheService {
     request_context_ = context;
   }
 
-  // TODO(jennb): API to set service settings, like file paths for storage
-
   // Track which processes are using this appcache service.
   void RegisterBackend(AppCacheBackendImpl* backend_impl);
   void UnregisterBackend(AppCacheBackendImpl* backend_impl);
diff --git a/webkit/appcache/appcache_unittest.cc b/webkit/appcache/appcache_unittest.cc
index b5c1772..3d33358 100644
--- a/webkit/appcache/appcache_unittest.cc
+++ b/webkit/appcache/appcache_unittest.cc
@@ -46,9 +46,46 @@ TEST(AppCacheTest, AddModifyEntry) {
   AppCacheEntry entry3(AppCacheEntry::EXPLICIT);
   cache->AddOrModifyEntry(kUrl1, entry3);
   EXPECT_EQ((AppCacheEntry::MASTER | AppCacheEntry::EXPLICIT),
-    cache->GetEntry(kUrl1)->types());
+            cache->GetEntry(kUrl1)->types());
   EXPECT_EQ(entry2.types(), cache->GetEntry(kUrl2)->types());  // unchanged
 }
 
+TEST(AppCacheTest, InitializeWithManifest) {
+  AppCacheService service;
+
+  scoped_refptr<AppCache> cache = new AppCache(&service, 1234);
+  EXPECT_TRUE(cache->fallback_namespaces_.empty());
+  EXPECT_TRUE(cache->online_whitelist_namespaces_.empty());
+  EXPECT_FALSE(cache->online_whitelist_all_);
+
+  Manifest manifest;
+  manifest.explicit_urls.insert("http://one.com");
+  manifest.explicit_urls.insert("http://two.com");
+  manifest.fallback_namespaces.push_back(
+      FallbackNamespace(GURL("http://fb1.com"), GURL("http://fbone.com")));
+  manifest.online_whitelist_namespaces.push_back(GURL("http://w1.com"));
+  manifest.online_whitelist_namespaces.push_back(GURL("http://w2.com"));
+  manifest.online_whitelist_all = true;
+
+  cache->InitializeWithManifest(&manifest);
+  const std::vector<FallbackNamespace>& fallbacks =
+      cache->fallback_namespaces_;
+  size_t expected = 1;
+  EXPECT_EQ(expected, fallbacks.size());
+  EXPECT_EQ(GURL("http://fb1.com"), fallbacks[0].first);
+  EXPECT_EQ(GURL("http://fbone.com"), fallbacks[0].second);
+  const std::vector<GURL>& whitelist = cache->online_whitelist_namespaces_;
+  expected = 2;
+  EXPECT_EQ(expected, whitelist.size());
+  EXPECT_EQ(GURL("http://w1.com"), whitelist[0]);
+  EXPECT_EQ(GURL("http://w2.com"), whitelist[1]);
+  EXPECT_TRUE(cache->online_whitelist_all_);
+
+  // Ensure collections in manifest were taken over by the cache rather than
+  // copied.
+  EXPECT_TRUE(manifest.fallback_namespaces.empty());
+  EXPECT_TRUE(manifest.online_whitelist_namespaces.empty());
+}
+
 }  // namespace appacache
 
diff --git a/webkit/appcache/appcache_update_job.cc b/webkit/appcache/appcache_update_job.cc
new file mode 100644
index 0000000..7732faf
--- /dev/null
+++ b/webkit/appcache/appcache_update_job.cc
@@ -0,0 +1,671 @@
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "webkit/appcache/appcache_update_job.h"
+
+#include "base/compiler_specific.h"
+#include "base/message_loop.h"
+#include "net/base/io_buffer.h"
+#include "net/base/load_flags.h"
+#include "webkit/appcache/appcache_group.h"
+#include "webkit/appcache/appcache_host.h"
+
+namespace appcache {
+
+static const int kBufferSize = 4096;
+static const size_t kMaxConcurrentUrlFetches = 2;
+
+// Extra info associated with requests for use during response processing.
+// This info is deleted when the URLRequest is deleted.
+struct UpdateJobInfo :  public URLRequest::UserData {
+  enum RequestType {
+    MANIFEST_FETCH,
+    URL_FETCH,
+    MANIFEST_REFETCH,
+  };
+
+  explicit UpdateJobInfo(RequestType request_type)
+      : type(request_type),
+        buffer(new net::IOBuffer(kBufferSize)) {
+  }
+
+  RequestType type;
+  scoped_refptr<net::IOBuffer> buffer;
+  // TODO(jennb): need storage info to stream response data to storage
+};
+
+// Helper class for collecting hosts per frontend when sending notifications
+// so that only one notification is sent for all hosts using the same frontend.
+class HostNotifier {
+ public:
+  typedef std::vector<int> HostIds;
+  typedef std::map<AppCacheFrontend*, HostIds> NotifyHostMap;
+
+  // Caller is responsible for ensuring there will be no duplicate hosts.
+  void AddHost(AppCacheHost* host) {
+    std::pair<NotifyHostMap::iterator , bool> ret = hosts_to_notify.insert(
+        NotifyHostMap::value_type(host->frontend(), HostIds()));
+    ret.first->second.push_back(host->host_id());
+  }
+
+  void AddHosts(const std::set<AppCacheHost*>& hosts) {
+    for (std::set<AppCacheHost*>::const_iterator it = hosts.begin();
+         it != hosts.end(); ++it) {
+      AddHost(*it);
+    }
+  }
+
+  void SendNotifications(EventID event_id) {
+    for (NotifyHostMap::iterator it = hosts_to_notify.begin();
+         it != hosts_to_notify.end(); ++it) {
+      AppCacheFrontend* frontend = it->first;
+      frontend->OnEventRaised(it->second, event_id);
+    }
+  }
+
+ private:
+  NotifyHostMap hosts_to_notify;
+};
+
+AppCacheUpdateJob::AppCacheUpdateJob(AppCacheService* service,
+                                     AppCacheGroup* group)
+    : ALLOW_THIS_IN_INITIALIZER_LIST(method_factory_(this)),
+      service_(service),
+      group_(group),
+      update_type_(UNKNOWN_TYPE),
+      internal_state_(FETCH_MANIFEST),
+      master_entries_completed_(0),
+      url_fetches_completed_(0),
+      manifest_url_request_(NULL) {
+  DCHECK(group_);
+  manifest_url_ = group_->manifest_url();
+}
+
+AppCacheUpdateJob::~AppCacheUpdateJob() {
+  Cancel();
+
+  DCHECK(!manifest_url_request_);
+  DCHECK(pending_url_fetches_.empty());
+
+  group_->SetUpdateStatus(AppCacheGroup::IDLE);
+}
+
+void AppCacheUpdateJob::StartUpdate(AppCacheHost* host,
+                                    const GURL& new_master_resource) {
+  DCHECK(group_->update_job() == this);
+
+  if (!new_master_resource.is_empty()) {
+    /* TODO(jennb): uncomment when processing master entries is implemented
+    std::pair<PendingMasters::iterator, bool> ret =
+        pending_master_entries_.insert(
+            PendingMasters::value_type(new_master_resource, PendingHosts()));
+    ret.first->second.push_back(host);
+    */
+  }
+
+  // Notify host (if any) if already checking or downloading.
+  appcache::AppCacheGroup::UpdateStatus update_status = group_->update_status();
+  if (update_status == AppCacheGroup::CHECKING ||
+      update_status == AppCacheGroup::DOWNLOADING) {
+    if (host) {
+      NotifySingleHost(host, CHECKING_EVENT);
+      if (update_status == AppCacheGroup::DOWNLOADING)
+        NotifySingleHost(host, DOWNLOADING_EVENT);
+    }
+    return;
+  }
+
+  // Begin update process for the group.
+  group_->SetUpdateStatus(AppCacheGroup::CHECKING);
+  if (group_->HasCache()) {
+    update_type_ = UPGRADE_ATTEMPT;
+    NotifyAllAssociatedHosts(CHECKING_EVENT);
+  } else {
+    update_type_ = CACHE_ATTEMPT;
+    DCHECK(host);
+    NotifySingleHost(host, CHECKING_EVENT);
+  }
+
+  FetchManifest(true);
+}
+
+void AppCacheUpdateJob::FetchManifest(bool is_first_fetch) {
+  DCHECK(!manifest_url_request_);
+  manifest_url_request_ = new URLRequest(manifest_url_, this);
+  UpdateJobInfo::RequestType fetch_type = is_first_fetch ?
+      UpdateJobInfo::MANIFEST_FETCH : UpdateJobInfo::MANIFEST_REFETCH;
+  manifest_url_request_->SetUserData(this, new UpdateJobInfo(fetch_type));
+  manifest_url_request_->set_context(service_->request_context());
+  // TODO(jennb): add "If-Modified-Since" if have previous date
+  manifest_url_request_->set_load_flags(
+      manifest_url_request_->load_flags() | net::LOAD_DISABLE_INTERCEPT);
+  manifest_url_request_->Start();
+}
+
+void AppCacheUpdateJob::OnResponseStarted(URLRequest *request) {
+  if (request->status().is_success())
+    ReadResponseData(request);
+  else
+    OnResponseCompleted(request);
+}
+
+void AppCacheUpdateJob::ReadResponseData(URLRequest* request) {
+  if (internal_state_ == CACHE_FAILURE)
+    return;
+
+  int bytes_read = 0;
+  UpdateJobInfo* info =
+      static_cast<UpdateJobInfo*>(request->GetUserData(this));
+  request->Read(info->buffer, kBufferSize, &bytes_read);
+  OnReadCompleted(request, bytes_read);
+}
+
+void AppCacheUpdateJob::OnReadCompleted(URLRequest* request, int bytes_read) {
+  bool data_consumed = true;
+  if (request->status().is_success() && bytes_read > 0) {
+    UpdateJobInfo* info =
+        static_cast<UpdateJobInfo*>(request->GetUserData(this));
+
+    data_consumed = ConsumeResponseData(request, info, bytes_read);
+    if (data_consumed) {
+      bytes_read = 0;
+      while (request->Read(info->buffer, kBufferSize, &bytes_read)) {
+        if (bytes_read > 0) {
+          data_consumed = ConsumeResponseData(request, info, bytes_read);
+          if (!data_consumed)
+            break;  // wait for async data processing, then read more
+        } else {
+          break;
+        }
+      }
+    }
+  }
+
+  if (data_consumed && !request->status().is_io_pending())
+    OnResponseCompleted(request);
+}
+
+bool AppCacheUpdateJob::ConsumeResponseData(URLRequest* request,
+                                            UpdateJobInfo* info,
+                                            int bytes_read) {
+  switch (info->type) {
+    case UpdateJobInfo::MANIFEST_FETCH:
+      manifest_data_.append(info->buffer->data(), bytes_read);
+      break;
+    case UpdateJobInfo::URL_FETCH:
+      // TODO(jennb): stream data to storage. will be async so need to wait
+      // for callback before reading next chunk.
+      // For now, schedule a task to continue reading to simulate async-ness.
+      MessageLoop::current()->PostTask(FROM_HERE,
+          method_factory_.NewRunnableMethod(
+              &AppCacheUpdateJob::ReadResponseData, request));
+      return false;
+    case UpdateJobInfo::MANIFEST_REFETCH:
+      manifest_refetch_data_.append(info->buffer->data(), bytes_read);
+      break;
+    default:
+      NOTREACHED();
+  }
+  return true;
+}
+
+void AppCacheUpdateJob::OnReceivedRedirect(URLRequest* request,
+                                           const GURL& new_url,
+                                           bool* defer_redirect) {
+  // Redirect is not allowed by the update process.
+  request->Cancel();
+  OnResponseCompleted(request);
+}
+
+void AppCacheUpdateJob::OnResponseCompleted(URLRequest* request) {
+  // TODO(jennb): think about retrying for 503s where retry-after is 0
+  UpdateJobInfo* info =
+      static_cast<UpdateJobInfo*>(request->GetUserData(this));
+  switch (info->type) {
+    case UpdateJobInfo::MANIFEST_FETCH:
+      HandleManifestFetchCompleted(request);
+      break;
+    case UpdateJobInfo::URL_FETCH:
+      HandleUrlFetchCompleted(request);
+      break;
+    case UpdateJobInfo::MANIFEST_REFETCH:
+      HandleManifestRefetchCompleted(request);
+      break;
+    default:
+      NOTREACHED();
+  }
+
+  delete request;
+}
+
+void AppCacheUpdateJob::HandleManifestFetchCompleted(URLRequest* request) {
+  DCHECK(internal_state_ == FETCH_MANIFEST);
+  manifest_url_request_ = NULL;
+
+  if (!request->status().is_success()) {
+    LOG(INFO) << "Request non-success, status: " << request->status().status()
+        << " os_error: " << request->status().os_error();
+    internal_state_ = CACHE_FAILURE;
+    MaybeCompleteUpdate();  // if not done, run async cache failure steps
+    return;
+  }
+
+  int response_code = request->GetResponseCode();
+  std::string mime_type;
+  request->GetMimeType(&mime_type);
+
+  if (response_code == 200 && mime_type == kManifestMimeType) {
+    if (update_type_ == UPGRADE_ATTEMPT)
+      CheckIfManifestChanged();  // continues asynchronously
+    else
+      ContinueHandleManifestFetchCompleted(true);
+  } else if (response_code == 304 && update_type_ == UPGRADE_ATTEMPT) {
+    ContinueHandleManifestFetchCompleted(false);
+  } else if (response_code == 404 || response_code == 410) {
+    group_->set_obsolete(true);
+    NotifyAllAssociatedHosts(OBSOLETE_EVENT);
+    NotifyAllPendingMasterHosts(ERROR_EVENT);
+    DeleteSoon();
+  } else {
+    LOG(INFO) << "Cache failure, response code: " << response_code;
+    internal_state_ = CACHE_FAILURE;
+    MaybeCompleteUpdate();  // if not done, run async cache failure steps
+  }
+}
+
+void AppCacheUpdateJob::ContinueHandleManifestFetchCompleted(bool changed) {
+  DCHECK(internal_state_ == FETCH_MANIFEST);
+
+  if (!changed) {
+    DCHECK(update_type_ == UPGRADE_ATTEMPT);
+    internal_state_ = NO_UPDATE;
+    MaybeCompleteUpdate();  // if not done, run async 6.9.4 step 7 substeps
+    return;
+  }
+
+  Manifest manifest;
+  if (!ParseManifest(manifest_url_, manifest_data_.data(),
+                     manifest_data_.length(), manifest)) {
+    LOG(INFO) << "Failed to parse manifest: " << manifest_url_;
+    internal_state_ = CACHE_FAILURE;
+    MaybeCompleteUpdate();  // if not done, run async cache failure steps
+    return;
+  }
+
+  // Proceed with update process. Section 6.9.4 steps 8-20.
+  internal_state_ = DOWNLOADING;
+  inprogress_cache_ = new AppCache(service_, service_->NewCacheId());
+  inprogress_cache_->set_owning_group(group_);
+  BuildUrlFileList(manifest);
+  inprogress_cache_->InitializeWithManifest(&manifest);
+
+  // Associate all pending master hosts with the newly created cache.
+  for (PendingMasters::iterator it = pending_master_entries_.begin();
+       it != pending_master_entries_.end(); ++it) {
+    PendingHosts hosts = it->second;
+    for (PendingHosts::iterator host_it = hosts.begin();
+         host_it != hosts.end(); ++host_it) {
+      AppCacheHost* host = *host_it;
+      host->AssociateCache(inprogress_cache_);
+    }
+  }
+
+  group_->SetUpdateStatus(AppCacheGroup::DOWNLOADING);
+  NotifyAllAssociatedHosts(DOWNLOADING_EVENT);
+  FetchUrls();
+  MaybeCompleteUpdate();  // if not done, continues when async fetches complete
+}
+
+void AppCacheUpdateJob::HandleUrlFetchCompleted(URLRequest* request) {
+  DCHECK(internal_state_ == DOWNLOADING);
+
+  const GURL& url = request->original_url();
+  pending_url_fetches_.erase(url);
+  ++url_fetches_completed_;
+
+  int response_code = request->GetResponseCode();
+  AppCacheEntry& entry = url_file_list_.find(url)->second;
+
+  if (request->status().is_success() && response_code == 200) {
+    // TODO(jennb): associate storage with the new entry
+    inprogress_cache_->AddEntry(url, entry);
+
+    // Foreign entries will be detected during cache selection.
+    // Note: 6.9.4, step 17.9 possible optimization: if resource is HTML or XML
+    // file whose root element is an html element with a manifest attribute
+    // whose value doesn't match the manifest url of the application cache
+    // being processed, mark the entry as being foreign.
+  } else {
+    LOG(INFO) << "Request status: " << request->status().status()
+        << " os_error: " << request->status().os_error()
+        << " response code: " << response_code;
+
+    // TODO(jennb): discard any stored data for this entry
+    if (entry.IsExplicit() || entry.IsFallback()) {
+      internal_state_ = CACHE_FAILURE;
+
+      // Cancel any pending URL requests.
+      for (PendingUrlFetches::iterator it = pending_url_fetches_.begin();
+           it != pending_url_fetches_.end(); ++it) {
+        it->second->Cancel();
+        delete it->second;
+      }
+
+      url_fetches_completed_ +=
+          pending_url_fetches_.size() + urls_to_fetch_.size();
+      pending_url_fetches_.clear();
+      urls_to_fetch_.clear();
+    } else if (response_code == 404 || response_code == 410) {
+      // Entry is skipped.  They are dropped from the cache.
+    } else if (update_type_ == UPGRADE_ATTEMPT) {
+      // Copy the resource and its metadata from the newest complete cache.
+      AppCache* cache = group_->newest_complete_cache();
+      AppCacheEntry* copy = cache->GetEntry(url);
+      if (copy)
+        CopyEntryToCache(url, *copy, &entry);
+    }
+  }
+
+  // Fetch another URL now that one request has completed.
+  if (internal_state_ != CACHE_FAILURE)
+    FetchUrls();
+
+  MaybeCompleteUpdate();
+}
+
+void AppCacheUpdateJob::HandleManifestRefetchCompleted(URLRequest* request) {
+  DCHECK(internal_state_ == REFETCH_MANIFEST);
+  manifest_url_request_ = NULL;
+
+  int response_code = request->GetResponseCode();
+  if (response_code == 304 || manifest_data_ == manifest_refetch_data_) {
+    AppCacheEntry entry(AppCacheEntry::MANIFEST);
+    // TODO(jennb): add manifest_data_ to storage and put storage key in entry
+    // Also store response headers from request for HTTP cache control.
+    inprogress_cache_->AddOrModifyEntry(manifest_url_, entry);
+    inprogress_cache_->set_update_time(base::TimeTicks::Now());
+
+    // TODO(jennb): start of part to make async (cache storage may fail;
+    // group storage may fail)
+    inprogress_cache_->set_complete(true);
+
+    // TODO(jennb): write new cache to storage here
+    group_->AddCache(inprogress_cache_);
+    // TODO(jennb): write new group to storage here
+    inprogress_cache_ = NULL;
+
+    if (update_type_ == CACHE_ATTEMPT) {
+      NotifyAllAssociatedHosts(CACHED_EVENT);
+    } else {
+      NotifyAllAssociatedHosts(UPDATE_READY_EVENT);
+    }
+    DeleteSoon();
+    // TODO(jennb): end of part that needs to be made async.
+  } else {
+    LOG(INFO) << "Request status: " << request->status().status()
+        << " os_error: " << request->status().os_error()
+        << " response code: " << response_code;
+    ScheduleUpdateRetry(kRerunDelayMs);
+    internal_state_ = CACHE_FAILURE;
+    HandleCacheFailure();
+  }
+}
+
+void AppCacheUpdateJob::NotifySingleHost(AppCacheHost* host,
+                                         EventID event_id) {
+  std::vector<int> ids(1, host->host_id());
+  host->frontend()->OnEventRaised(ids, event_id);
+}
+
+void AppCacheUpdateJob::NotifyAllPendingMasterHosts(EventID event_id) {
+  // Collect hosts so we only send one notification per frontend.
+  // A host can only be associated with a single pending master entry
+  // so no need to worry about duplicate hosts being added to the notifier.
+  HostNotifier host_notifier;
+  for (PendingMasters::iterator it = pending_master_entries_.begin();
+       it != pending_master_entries_.end(); ++it) {
+    PendingHosts hosts = it->second;
+    for (PendingHosts::iterator host_it = hosts.begin();
+         host_it != hosts.end(); ++host_it) {
+      AppCacheHost* host = *host_it;
+      host_notifier.AddHost(host);
+    }
+  }
+
+  host_notifier.SendNotifications(event_id);
+}
+
+void AppCacheUpdateJob::NotifyAllAssociatedHosts(EventID event_id) {
+  // Collect hosts so we only send one notification per frontend.
+  // A host can only be associated with a single cache so no need to worry
+  // about duplicate hosts being added to the notifier.
+  HostNotifier host_notifier;
+  if (inprogress_cache_) {
+    DCHECK(internal_state_ == DOWNLOADING || internal_state_ == CACHE_FAILURE);
+    host_notifier.AddHosts(inprogress_cache_->associated_hosts());
+  }
+
+  AppCacheGroup::Caches old_caches = group_->old_caches();
+  for (AppCacheGroup::Caches::const_iterator it = old_caches.begin();
+       it != old_caches.end(); ++it) {
+    host_notifier.AddHosts((*it)->associated_hosts());
+  }
+
+  AppCache* newest_cache = group_->newest_complete_cache();
+  if (newest_cache)
+    host_notifier.AddHosts(newest_cache->associated_hosts());
+
+  // TODO(jennb): if progress event, also pass params lengthComputable=true,
+  // total = url_file_list_.size(), loaded=url_fetches_completed_.
+  host_notifier.SendNotifications(event_id);
+}
+
+void AppCacheUpdateJob::CheckIfManifestChanged() {
+  DCHECK(update_type_ == UPGRADE_ATTEMPT);
+  /*
+  AppCacheEntry* entry =
+      group_->newest_complete_cache()->GetEntry(manifest_url_);
+  */
+  // TODO(jennb): load manifest data from entry (async), continues in callback
+  // callback invokes ContinueCheckIfManifestChanged
+  // For now, schedule a task to continue checking with fake loaded data
+  MessageLoop::current()->PostTask(FROM_HERE,
+      method_factory_.NewRunnableMethod(
+          &AppCacheUpdateJob::ContinueCheckIfManifestChanged,
+          simulate_manifest_changed_ ? "different" : manifest_data_));
+}
+
+void AppCacheUpdateJob::ContinueCheckIfManifestChanged(
+    const std::string& loaded_manifest) {
+  ContinueHandleManifestFetchCompleted(manifest_data_ != loaded_manifest);
+}
+
+void AppCacheUpdateJob::BuildUrlFileList(const Manifest& manifest) {
+  for (base::hash_set<std::string>::const_iterator it =
+           manifest.explicit_urls.begin();
+       it != manifest.explicit_urls.end(); ++it) {
+    AddUrlToFileList(GURL(*it), AppCacheEntry::EXPLICIT);
+  }
+
+  const std::vector<FallbackNamespace>& fallbacks =
+      manifest.fallback_namespaces;
+  for (std::vector<FallbackNamespace>::const_iterator it = fallbacks.begin();
+       it != fallbacks.end(); ++it) {
+     AddUrlToFileList(it->second, AppCacheEntry::FALLBACK);
+  }
+
+  // Add all master entries from newest complete cache.
+  if (update_type_ == UPGRADE_ATTEMPT) {
+    const AppCache::EntryMap& entries =
+        group_->newest_complete_cache()->entries();
+    for (AppCache::EntryMap::const_iterator it = entries.begin();
+         it != entries.end(); ++it) {
+      const AppCacheEntry& entry = it->second;
+      if (entry.IsMaster())
+        AddUrlToFileList(it->first, AppCacheEntry::MASTER);
+    }
+  }
+}
+
+void AppCacheUpdateJob::AddUrlToFileList(const GURL& url, int type) {
+  std::pair<AppCache::EntryMap::iterator, bool> ret = url_file_list_.insert(
+      AppCache::EntryMap::value_type(url, AppCacheEntry(type)));
+
+  if (ret.second)
+    urls_to_fetch_.push_back(UrlToFetch(url, false));
+  else
+    ret.first->second.add_types(type);  // URL already exists. Merge types.
+}
+
+void AppCacheUpdateJob::FetchUrls() {
+  DCHECK(internal_state_ == DOWNLOADING);
+
+  // Fetch each URL in the list according to section 6.9.4 step 17.1-17.3.
+  // Fetch up to the concurrent limit. Other fetches will be triggered as each
+  // each fetch completes.
+  while (pending_url_fetches_.size() < kMaxConcurrentUrlFetches &&
+         !urls_to_fetch_.empty()) {
+    // Notify about progress first to ensure it starts from 0% in case any
+    // entries are skipped.
+    NotifyAllAssociatedHosts(PROGRESS_EVENT);
+
+    const GURL url = urls_to_fetch_.front().first;
+    bool storage_checked = urls_to_fetch_.front().second;
+    urls_to_fetch_.pop_front();
+
+    AppCache::EntryMap::iterator it = url_file_list_.find(url);
+    DCHECK(it != url_file_list_.end());
+    AppCacheEntry& entry = it->second;
+    if (ShouldSkipUrlFetch(entry)) {
+      ++url_fetches_completed_;
+    } else if (!storage_checked && MaybeLoadFromNewestCache(url, entry)) {
+      // Continues asynchronously after data is loaded from newest cache.
+    } else {
+      // Send URL request for the resource.
+      URLRequest* request = new URLRequest(url, this);
+      request->SetUserData(this, new UpdateJobInfo(UpdateJobInfo::URL_FETCH));
+      request->set_context(service_->request_context());
+      request->set_load_flags(
+          request->load_flags() | net::LOAD_DISABLE_INTERCEPT);
+      request->Start();
+      pending_url_fetches_.insert(PendingUrlFetches::value_type(url, request));
+    }
+  }
+}
+
+bool AppCacheUpdateJob::ShouldSkipUrlFetch(const AppCacheEntry& entry) {
+  if (entry.IsExplicit() || entry.IsFallback()) {
+    return false;
+  }
+
+  // TODO(jennb): decide if entry should be skipped to expire it from cache
+  return false;
+}
+
+bool AppCacheUpdateJob::MaybeLoadFromNewestCache(const GURL& url,
+                                                 AppCacheEntry& entry) {
+  if (update_type_ != UPGRADE_ATTEMPT)
+    return false;
+
+  AppCache* newest = group_->newest_complete_cache();
+  AppCacheEntry* copy_me = newest->GetEntry(url);
+  if (!copy_me)
+    return false;
+
+  // TODO(jennb): load HTTP headers for copy_me and wait for callback
+  // In callback:
+  // if HTTP caching semantics for entry allows its use,
+  //   CopyEntryData(url, copy_me, entry)
+  //   ++urls_fetches_completed_;
+  // Else, add url back to front of urls_to_fetch and call FetchUrls().
+  //   flag url somehow so that FetchUrls() doesn't end up here again.
+  // For now: post a message to pretend entry could not be copied
+  MessageLoop::current()->PostTask(FROM_HERE,
+      method_factory_.NewRunnableMethod(
+          &AppCacheUpdateJob::SimulateFailedLoadFromNewestCache, url));
+  return true;
+}
+
+// TODO(jennb): delete this after have real storage code
+void AppCacheUpdateJob::SimulateFailedLoadFromNewestCache(const GURL& url) {
+  if (internal_state_ == CACHE_FAILURE)
+    return;
+
+  // Re-insert url at front of fetch list. Indicate storage has been checked.
+  urls_to_fetch_.push_front(AppCacheUpdateJob::UrlToFetch(url, true));
+  FetchUrls();
+}
+
+void AppCacheUpdateJob::CopyEntryToCache(const GURL& url,
+                                         const AppCacheEntry& src,
+                                         AppCacheEntry* dest) {
+  DCHECK(dest);
+  // TODO(jennb): copy storage key from src to dest
+  inprogress_cache_->AddEntry(url, *dest);
+}
+
+bool AppCacheUpdateJob::MaybeCompleteUpdate() {
+  if (master_entries_completed_ != pending_master_entries_.size() ||
+      url_fetches_completed_ != url_file_list_.size() ) {
+    return false;
+  }
+
+  switch (internal_state_) {
+    case NO_UPDATE:
+      // 6.9.4 steps 7.3-7.7.
+      NotifyAllAssociatedHosts(NO_UPDATE_EVENT);
+      pending_master_entries_.clear();
+      DeleteSoon();
+      break;
+    case DOWNLOADING:
+      internal_state_ = REFETCH_MANIFEST;
+      FetchManifest(false);
+      return false;
+    case CACHE_FAILURE:
+      HandleCacheFailure();
+      break;
+    default:
+      NOTREACHED();
+  }
+  return true;
+}
+
+void AppCacheUpdateJob::HandleCacheFailure() {
+  // 6.9.4 cache failure steps 2-8.
+  NotifyAllAssociatedHosts(ERROR_EVENT);
+  pending_master_entries_.clear();
+
+  // Discard the inprogress cache.
+  // TODO(jennb): cleanup possible storage for entries in the cache
+  if (inprogress_cache_) {
+    inprogress_cache_->set_owning_group(NULL);
+    inprogress_cache_ = NULL;
+  }
+
+  // For a CACHE_ATTEMPT, group will be discarded when this update
+  // job removes its reference to the group. Nothing more to do here.
+
+  DeleteSoon();
+}
+
+void AppCacheUpdateJob::ScheduleUpdateRetry(int delay_ms) {
+  // TODO(jennb): post a delayed task with the "same parameters" as this job
+  // to retry the update at a later time. Need group, URLs of pending master
+  // entries and their hosts.
+}
+
+void AppCacheUpdateJob::Cancel() {
+  if (manifest_url_request_) {
+    delete manifest_url_request_;
+    manifest_url_request_ = NULL;
+  }
+
+  // TODO(jennb): code other cancel cleanup (pending url requests, storage)
+}
+
+void AppCacheUpdateJob::DeleteSoon() {
+  // TODO(jennb): revisit if update should be deleting itself
+  MessageLoop::current()->DeleteSoon(FROM_HERE, this);
+}
+}  // namespace appcache
diff --git a/webkit/appcache/appcache_update_job.h b/webkit/appcache/appcache_update_job.h
new file mode 100644
index 0000000..160e27e
--- /dev/null
+++ b/webkit/appcache/appcache_update_job.h
@@ -0,0 +1,184 @@
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef WEBKIT_APPCACHE_APPCACHE_UPDATE_JOB_H_
+#define WEBKIT_APPCACHE_APPCACHE_UPDATE_JOB_H_
+
+#include <deque>
+#include <map>
+
+#include "base/ref_counted.h"
+#include "base/task.h"
+#include "googleurl/src/gurl.h"
+#include "net/url_request/url_request.h"
+#include "webkit/appcache/appcache.h"
+#include "webkit/appcache/appcache_interfaces.h"
+
+namespace appcache {
+
+struct UpdateJobInfo;
+
+// Application cache Update algorithm and state.
+class AppCacheUpdateJob : public URLRequest::Delegate {
+ public:
+  AppCacheUpdateJob(AppCacheService* service, AppCacheGroup* group);
+  ~AppCacheUpdateJob();
+
+  // Triggers the update process or adds more info if this update is already
+  // in progress.
+  void StartUpdate(AppCacheHost* host, const GURL& new_master_resource);
+
+
+  // TODO(jennb): add callback method for writing data to storage
+  // TODO(jennb): add callback method for reading data from storage
+
+ private:
+  friend class ScopedRunnableMethodFactory<AppCacheUpdateJob>;
+  friend class AppCacheUpdateJobTest;
+
+  // Master entries have multiple hosts, for example, the same page is opened
+  // in different tabs.
+  // TODO(jennb): detect when hosts are deleted
+  typedef std::vector<AppCacheHost*> PendingHosts;
+  typedef std::map<GURL, PendingHosts> PendingMasters;
+  typedef std::map<GURL, URLRequest*> PendingUrlFetches;
+  typedef std::pair<GURL, bool> UrlToFetch;  // flag TRUE if storage checked
+
+  static const int kRerunDelayMs = 1000;
+
+  enum UpdateType {
+    UNKNOWN_TYPE,
+    UPGRADE_ATTEMPT,
+    CACHE_ATTEMPT,
+  };
+
+  enum InternalUpdateState {
+    FETCH_MANIFEST,
+    NO_UPDATE,
+    DOWNLOADING,
+    REFETCH_MANIFEST,
+    CACHE_FAILURE,
+    CANCELLED,
+  };
+
+  // Methods for URLRequest::Delegate.
+  void OnResponseStarted(URLRequest* request);
+  void OnReadCompleted(URLRequest* request, int bytes_read);
+  void OnReceivedRedirect(URLRequest* request,
+                          const GURL& new_url,
+                          bool* defer_redirect);
+  // TODO(jennb): any other delegate callbacks to handle? certificate?
+
+  void FetchManifest(bool is_first_fetch);
+
+  void OnResponseCompleted(URLRequest* request);
+
+  void ReadResponseData(URLRequest* request);
+
+  // Returns false if response data is processed asynchronously, in which
+  // case a callback will be invoked when it is safe to continue reading
+  // more response data from the request.
+  bool ConsumeResponseData(URLRequest* request,
+                           UpdateJobInfo* info,
+                           int bytes_read);
+
+  void HandleManifestFetchCompleted(URLRequest* request);
+  void ContinueHandleManifestFetchCompleted(bool changed);
+  void HandleUrlFetchCompleted(URLRequest* request);
+  void HandleManifestRefetchCompleted(URLRequest* request);
+
+  void NotifySingleHost(AppCacheHost* host, EventID event_id);
+  void NotifyAllPendingMasterHosts(EventID event_id);
+  void NotifyAllAssociatedHosts(EventID event_id);
+
+  // Checks if manifest is byte for byte identical with the manifest
+  // in the newest application cache.
+  void CheckIfManifestChanged();
+  void ContinueCheckIfManifestChanged(const std::string& loaded_manifest);
+
+  // TODO(jennb): delete when able to mock storage behavior
+  void SimulateManifestChanged(bool changed) {
+    simulate_manifest_changed_ = changed;
+  }
+
+  // Creates the list of files that may need to be fetched and initiates
+  // fetches. Section 6.9.4 steps 12-17
+  void BuildUrlFileList(const Manifest& manifest);
+  void AddUrlToFileList(const GURL& url, int type);
+  void FetchUrls();
+  bool ShouldSkipUrlFetch(const AppCacheEntry& entry);
+
+  // Asynchronously loads the entry from the newest complete cache if the
+  // HTTP caching semantics allow.
+  // Returns false if immediately obvious that data cannot be loaded from
+  // newest complete cache.
+  bool MaybeLoadFromNewestCache(const GURL& url, AppCacheEntry& entry);
+
+  // TODO(jennb): delete me after storage code added
+  void SimulateFailedLoadFromNewestCache(const GURL& url);
+
+  // Copies the data from src entry to dest entry and adds the modified
+  // entry to the inprogress cache.
+  void CopyEntryToCache(const GURL& url, const AppCacheEntry& src,
+                        AppCacheEntry* dest);
+
+  // Does nothing if update process is still waiting for pending master
+  // entries or URL fetches to complete downloading. Otherwise, completes
+  // the update process.
+  // Returns true if update process is completed.
+  bool MaybeCompleteUpdate();
+
+  // Runs the cache failure steps after all pending master entry downloads
+  // have completed.
+  void HandleCacheFailure();
+
+  // Schedules a rerun of the entire update with the same parameters as
+  // this update job after a short delay.
+  void ScheduleUpdateRetry(int delay_ms);
+
+  void Cancel();
+
+  // Deletes this object after letting the stack unwind.
+  void DeleteSoon();
+
+  // This factory will be used to schedule invocations of various methods.
+  ScopedRunnableMethodFactory<AppCacheUpdateJob> method_factory_;
+
+  GURL manifest_url_;  // here for easier access
+  AppCacheService* service_;
+  scoped_refptr<AppCache> inprogress_cache_;
+  scoped_refptr<AppCacheGroup> group_;
+
+  UpdateType update_type_;
+  InternalUpdateState internal_state_;
+
+  PendingMasters pending_master_entries_;
+  size_t master_entries_completed_;
+
+  // URLs of files to fetch along with their flags.
+  AppCache::EntryMap url_file_list_;
+  size_t url_fetches_completed_;
+
+  // Helper container to track which urls have not been fetched yet. URLs are
+  // removed when the fetch is initiated. Flag indicates whether an attempt
+  // to load the URL from storage has already been tried and failed.
+  std::deque<UrlToFetch> urls_to_fetch_;
+
+  // Keep track of pending URL requests so we can cancel them if necessary.
+  URLRequest* manifest_url_request_;
+  PendingUrlFetches pending_url_fetches_;
+
+  // Temporary storage of manifest response data for parsing and comparison.
+  std::string manifest_data_;
+  std::string manifest_refetch_data_;
+
+  // TODO(jennb): delete when able to mock storage behavior
+  bool simulate_manifest_changed_;
+
+  DISALLOW_COPY_AND_ASSIGN(AppCacheUpdateJob);
+};
+
+}  // namespace appcache
+
+#endif  // WEBKIT_APPCACHE_APPCACHE_UPDATE_JOB_H_
diff --git a/webkit/appcache/appcache_update_job_unittest.cc b/webkit/appcache/appcache_update_job_unittest.cc
new file mode 100644
index 0000000..9fda1c6
--- /dev/null
+++ b/webkit/appcache/appcache_update_job_unittest.cc
@@ -0,0 +1,1172 @@
+// Copyright (c) 2009 The Chromium Authos. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+#include "base/stl_util-inl.h"
+#include "base/thread.h"
+#include "base/waitable_event.h"
+#include "net/url_request/url_request_test_job.h"
+#include "net/url_request/url_request_unittest.h"
+#include "webkit/appcache/appcache_group.h"
+#include "webkit/appcache/appcache_host.h"
+#include "webkit/appcache/appcache_service.h"
+#include "webkit/appcache/appcache_update_job.h"
+
+namespace appcache {
+class AppCacheUpdateJobTest;
+
+const wchar_t kDocRoot[] = L"webkit/appcache/data/appcache_unittest";
+
+class MockFrontend : public AppCacheFrontend {
+ public:
+  virtual void OnCacheSelected(int host_id, int64 cache_id,
+                               Status status) {
+  }
+
+  virtual void OnStatusChanged(const std::vector<int>& host_ids,
+                               Status status) {
+  }
+
+  virtual void OnEventRaised(const std::vector<int>& host_ids,
+                             EventID event_id) {
+    raised_events_.push_back(RaisedEvent(host_ids, event_id));
+  }
+
+  void AddExpectedEvent(const std::vector<int>& host_ids, EventID event_id) {
+    expected_events_.push_back(RaisedEvent(host_ids, event_id));
+  }
+
+  typedef std::vector<int> HostIds;
+  typedef std::pair<HostIds, EventID> RaisedEvent;
+  typedef std::vector<RaisedEvent> RaisedEvents;
+  RaisedEvents raised_events_;
+
+  // Set the expected events if verification needs to happen asynchronously.
+  RaisedEvents expected_events_;
+};
+
+// Helper class to let us call methods of AppCacheUpdateJobTest on a
+// thread of our choice.
+template <class Method>
+class WrapperTask : public Task {
+ public:
+  WrapperTask(AppCacheUpdateJobTest* test, Method method)
+      : test_(test),
+        method_(method) {
+  }
+
+  virtual void Run() {
+    (test_->*method_)( );
+  }
+
+ private:
+  AppCacheUpdateJobTest* test_;
+  Method method_;
+};
+
+// Helper factories to simulate redirected URL responses for tests.
+static URLRequestJob* RedirectFactory(URLRequest* request,
+                                      const std::string& scheme) {
+  return new URLRequestTestJob(request,
+                               URLRequestTestJob::test_redirect_headers(),
+                               URLRequestTestJob::test_data_1(),
+                               true);
+}
+
+class AppCacheUpdateJobTest : public testing::Test,
+                              public AppCacheGroup::Observer {
+ public:
+  AppCacheUpdateJobTest()
+      : ALLOW_THIS_IN_INITIALIZER_LIST(method_factory_(this)),
+        do_checks_after_update_finished_(false),
+        expect_group_obsolete_(false),
+        expect_group_has_cache_(false),
+        expect_old_cache_(NULL),
+        expect_newest_cache_(NULL),
+        tested_manifest_(NONE) {
+  }
+
+  static void SetUpTestCase() {
+    io_thread_.reset(new base::Thread("AppCacheUpdateJob IO  test thread"));
+    base::Thread::Options options(MessageLoop::TYPE_IO, 0);
+    io_thread_->StartWithOptions(options);
+
+    http_server_ =
+        HTTPTestServer::CreateServer(kDocRoot, io_thread_->message_loop());
+    ASSERT_TRUE(http_server_);
+  }
+
+  static void TearDownTestCase() {
+    http_server_ = NULL;
+    io_thread_.reset(NULL);
+  }
+
+  // Use a separate IO thread to run a test. Thread will be destroyed
+  // when it goes out of scope.
+  template <class Method>
+  void RunTestOnIOThread(Method method) {
+    event_ .reset(new base::WaitableEvent(false, false));
+    io_thread_->message_loop()->PostTask(
+        FROM_HERE, new WrapperTask<Method>(this, method));
+
+    // Wait until task is done before exiting the test.
+    event_->Wait();
+  }
+
+  void StartCacheAttemptTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(service_.get(), GURL("http://failme"));
+
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    MockFrontend mock_frontend;
+    AppCacheHost host(1, &mock_frontend, service_.get());
+
+    update->StartUpdate(&host, GURL::EmptyGURL());
+
+    // Verify state.
+    EXPECT_EQ(AppCacheUpdateJob::CACHE_ATTEMPT, update->update_type_);
+    EXPECT_EQ(AppCacheUpdateJob::FETCH_MANIFEST, update->internal_state_);
+    EXPECT_EQ(AppCacheGroup::CHECKING, group_->update_status());
+
+    // Verify notifications.
+    MockFrontend::RaisedEvents& events = mock_frontend.raised_events_;
+    size_t expected = 1;
+    EXPECT_EQ(expected, events.size());
+    EXPECT_EQ(expected, events[0].first.size());
+    EXPECT_EQ(host.host_id(), events[0].first[0]);
+    EXPECT_EQ(CHECKING_EVENT, events[0].second);
+
+    // Abort as we're not testing actual URL fetches in this test.
+    delete update;
+    UpdateFinished();
+  }
+
+  void StartUpgradeAttemptTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    {
+      MakeService();
+      group_ = new AppCacheGroup(service_.get(), GURL("http://failme"));
+
+      // Give the group some existing caches.
+      AppCache* cache1 = MakeCacheForGroup(1);
+      AppCache* cache2 = MakeCacheForGroup(2);
+
+      // Associate some hosts with caches in the group.
+      MockFrontend mock_frontend1;
+      MockFrontend mock_frontend2;
+      MockFrontend mock_frontend3;
+
+      AppCacheHost host1(1, &mock_frontend1, service_.get());
+      host1.AssociateCache(cache1);
+
+      AppCacheHost host2(2, &mock_frontend2, service_.get());
+      host2.AssociateCache(cache2);
+
+      AppCacheHost host3(3, &mock_frontend1, service_.get());
+      host3.AssociateCache(cache1);
+
+      AppCacheHost host4(4, &mock_frontend3, service_.get());
+
+      AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+      group_->update_job_ = update;
+      update->StartUpdate(&host4, GURL::EmptyGURL());
+
+      // Verify state after starting an update.
+      EXPECT_EQ(AppCacheUpdateJob::UPGRADE_ATTEMPT, update->update_type_);
+      EXPECT_EQ(AppCacheUpdateJob::FETCH_MANIFEST, update->internal_state_);
+      EXPECT_EQ(AppCacheGroup::CHECKING, group_->update_status());
+
+      // Verify notifications.
+      MockFrontend::RaisedEvents& events = mock_frontend1.raised_events_;
+      size_t expected = 1;
+      EXPECT_EQ(expected, events.size());
+      expected = 2;  // 2 hosts using frontend1
+      EXPECT_EQ(expected, events[0].first.size());
+      MockFrontend::HostIds& host_ids = events[0].first;
+      EXPECT_TRUE(std::find(host_ids.begin(), host_ids.end(), host1.host_id())
+          != host_ids.end());
+      EXPECT_TRUE(std::find(host_ids.begin(), host_ids.end(), host3.host_id())
+          != host_ids.end());
+      EXPECT_EQ(CHECKING_EVENT, events[0].second);
+
+      events = mock_frontend2.raised_events_;
+      expected = 1;
+      EXPECT_EQ(expected, events.size());
+      EXPECT_EQ(expected, events[0].first.size());  // 1 host using frontend2
+      EXPECT_EQ(host2.host_id(), events[0].first[0]);
+      EXPECT_EQ(CHECKING_EVENT, events[0].second);
+
+      events = mock_frontend3.raised_events_;
+      EXPECT_TRUE(events.empty());
+
+      // Abort as we're not testing actual URL fetches in this test.
+      delete update;
+    }
+    UpdateFinished();
+  }
+
+  void CacheAttemptFetchManifestFailTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(service_.get(), GURL("http://failme"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    MockFrontend* frontend = MakeMockFrontend();
+    AppCacheHost* host = MakeHost(1, frontend);
+    update->StartUpdate(host, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    update->manifest_url_request_->SimulateError(-100);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = false;
+    expect_group_has_cache_ = false;
+    frontend->AddExpectedEvent(MockFrontend::HostIds(1, host->host_id()),
+                               CHECKING_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void UpgradeFetchManifestFailTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(service_.get(), GURL("http://failme"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    AppCache* cache = MakeCacheForGroup(1);
+    MockFrontend* frontend1 = MakeMockFrontend();
+    MockFrontend* frontend2 = MakeMockFrontend();
+    AppCacheHost* host1 = MakeHost(1, frontend1);
+    AppCacheHost* host2 = MakeHost(2, frontend2);
+    host1->AssociateCache(cache);
+    host2->AssociateCache(cache);
+
+    update->StartUpdate(NULL, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    update->manifest_url_request_->SimulateError(-100);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = false;
+    expect_group_has_cache_ = true;
+    expect_newest_cache_ = cache;  // newest cache unaffected by update
+    MockFrontend::HostIds ids1(1, host1->host_id());
+    frontend1->AddExpectedEvent(ids1, CHECKING_EVENT);
+    frontend1->AddExpectedEvent(ids1, ERROR_EVENT);
+    MockFrontend::HostIds ids2(1, host2->host_id());
+    frontend2->AddExpectedEvent(ids2, CHECKING_EVENT);
+    frontend2->AddExpectedEvent(ids2, ERROR_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void ManifestRedirectTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    URLRequest::RegisterProtocolFactory("http", RedirectFactory);
+
+    MakeService();
+    group_ = new AppCacheGroup(service_.get(), GURL("http://testme"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    MockFrontend* frontend = MakeMockFrontend();
+    AppCacheHost* host = MakeHost(1, frontend);
+    update->StartUpdate(host, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = false;
+    expect_group_has_cache_ = false;  // redirect is like a failed request
+    frontend->AddExpectedEvent(MockFrontend::HostIds(1, host->host_id()),
+                               CHECKING_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void ManifestWrongMimeTypeTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(
+        service_.get(), http_server_->TestServerPage("defaultresponse"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    MockFrontend* frontend = MakeMockFrontend();
+    AppCacheHost* host = MakeHost(1, frontend);
+    update->StartUpdate(host, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = false;
+    expect_group_has_cache_ = false;  // bad mime type is like a failed request
+    frontend->AddExpectedEvent(MockFrontend::HostIds(1, host->host_id()),
+                               CHECKING_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void ManifestNotFoundTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(
+        service_.get(), http_server_->TestServerPage("files/nosuchfile"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    AppCache* cache = MakeCacheForGroup(1);
+    MockFrontend* frontend1 = MakeMockFrontend();
+    MockFrontend* frontend2 = MakeMockFrontend();
+    AppCacheHost* host1 = MakeHost(1, frontend1);
+    AppCacheHost* host2 = MakeHost(2, frontend2);
+    host1->AssociateCache(cache);
+    host2->AssociateCache(cache);
+
+    update->StartUpdate(NULL, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = true;
+    expect_group_has_cache_ = true;
+    expect_newest_cache_ = cache;  // newest cache unaffected by update
+    MockFrontend::HostIds ids1(1, host1->host_id());
+    frontend1->AddExpectedEvent(ids1, CHECKING_EVENT);
+    frontend1->AddExpectedEvent(ids1, OBSOLETE_EVENT);
+    MockFrontend::HostIds ids2(1, host2->host_id());
+    frontend2->AddExpectedEvent(ids2, CHECKING_EVENT);
+    frontend2->AddExpectedEvent(ids2, OBSOLETE_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void ManifestGoneTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(
+      service_.get(), http_server_->TestServerPage("files/gone"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    MockFrontend* frontend = MakeMockFrontend();
+    AppCacheHost* host = MakeHost(1, frontend);
+    update->StartUpdate(host, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = true;
+    expect_group_has_cache_ = false;
+    frontend->AddExpectedEvent(MockFrontend::HostIds(1, host->host_id()),
+                               CHECKING_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void CacheAttemptNotModifiedTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(
+      service_.get(), http_server_->TestServerPage("files/notmodified"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    MockFrontend* frontend = MakeMockFrontend();
+    AppCacheHost* host = MakeHost(1, frontend);
+    update->StartUpdate(host, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = false;
+    expect_group_has_cache_ = false;  // treated like cache failure
+    frontend->AddExpectedEvent(MockFrontend::HostIds(1, host->host_id()),
+                               CHECKING_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void UpgradeNotModifiedTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(
+        service_.get(), http_server_->TestServerPage("files/notmodified"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    AppCache* cache = MakeCacheForGroup(1);
+    MockFrontend* frontend1 = MakeMockFrontend();
+    MockFrontend* frontend2 = MakeMockFrontend();
+    AppCacheHost* host1 = MakeHost(1, frontend1);
+    AppCacheHost* host2 = MakeHost(2, frontend2);
+    host1->AssociateCache(cache);
+    host2->AssociateCache(cache);
+
+    update->StartUpdate(NULL, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = false;
+    expect_group_has_cache_ = true;
+    expect_newest_cache_ = cache;  // newest cache unaffected by update
+    MockFrontend::HostIds ids1(1, host1->host_id());
+    frontend1->AddExpectedEvent(ids1, CHECKING_EVENT);
+    frontend1->AddExpectedEvent(ids1, NO_UPDATE_EVENT);
+    MockFrontend::HostIds ids2(1, host2->host_id());
+    frontend2->AddExpectedEvent(ids2, CHECKING_EVENT);
+    frontend2->AddExpectedEvent(ids2, NO_UPDATE_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void UpgradeManifestDataUnchangedTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(
+        service_.get(), http_server_->TestServerPage("files/manifest1"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    AppCache* cache = MakeCacheForGroup(1);
+    MockFrontend* frontend1 = MakeMockFrontend();
+    MockFrontend* frontend2 = MakeMockFrontend();
+    AppCacheHost* host1 = MakeHost(1, frontend1);
+    AppCacheHost* host2 = MakeHost(2, frontend2);
+    host1->AssociateCache(cache);
+    host2->AssociateCache(cache);
+
+    // TODO(jennb): simulate this by mocking storage behavior instead
+    update->SimulateManifestChanged(false);  // unchanged
+
+    update->StartUpdate(NULL, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = false;
+    expect_group_has_cache_ = true;
+    expect_newest_cache_ = cache;  // newest cache unaffected by update
+    MockFrontend::HostIds ids1(1, host1->host_id());
+    frontend1->AddExpectedEvent(ids1, CHECKING_EVENT);
+    frontend1->AddExpectedEvent(ids1, NO_UPDATE_EVENT);
+    MockFrontend::HostIds ids2(1, host2->host_id());
+    frontend2->AddExpectedEvent(ids2, CHECKING_EVENT);
+    frontend2->AddExpectedEvent(ids2, NO_UPDATE_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void BasicCacheAttemptSuccessTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(
+      service_.get(), http_server_->TestServerPage("files/manifest1"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    MockFrontend* frontend = MakeMockFrontend();
+    AppCacheHost* host = MakeHost(1, frontend);
+    update->StartUpdate(host, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = false;
+    expect_group_has_cache_ = true;
+    tested_manifest_ = MANIFEST1;
+    frontend->AddExpectedEvent(MockFrontend::HostIds(1, host->host_id()),
+                               CHECKING_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void BasicUpgradeSuccessTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(
+        service_.get(), http_server_->TestServerPage("files/manifest1"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    AppCache* cache = MakeCacheForGroup(service_->NewCacheId());
+    MockFrontend* frontend1 = MakeMockFrontend();
+    MockFrontend* frontend2 = MakeMockFrontend();
+    AppCacheHost* host1 = MakeHost(1, frontend1);
+    AppCacheHost* host2 = MakeHost(2, frontend2);
+    host1->AssociateCache(cache);
+    host2->AssociateCache(cache);
+
+    // TODO(jennb): simulate this by mocking storage behavior instead
+    update->SimulateManifestChanged(true);  // changed
+
+    update->StartUpdate(NULL, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = false;
+    expect_group_has_cache_ = true;
+    expect_old_cache_ = cache;
+    tested_manifest_ = MANIFEST1;
+    MockFrontend::HostIds ids1(1, host1->host_id());
+    frontend1->AddExpectedEvent(ids1, CHECKING_EVENT);
+    frontend1->AddExpectedEvent(ids1, DOWNLOADING_EVENT);
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);
+    frontend1->AddExpectedEvent(ids1, UPDATE_READY_EVENT);
+    MockFrontend::HostIds ids2(1, host2->host_id());
+    frontend2->AddExpectedEvent(ids2, CHECKING_EVENT);
+    frontend2->AddExpectedEvent(ids2, DOWNLOADING_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, UPDATE_READY_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void UpgradeSuccessMergedTypesTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(service_.get(),
+        http_server_->TestServerPage("files/manifest-merged-types"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    AppCache* cache = MakeCacheForGroup(service_->NewCacheId());
+    MockFrontend* frontend1 = MakeMockFrontend();
+    MockFrontend* frontend2 = MakeMockFrontend();
+    AppCacheHost* host1 = MakeHost(1, frontend1);
+    AppCacheHost* host2 = MakeHost(2, frontend2);
+    host1->AssociateCache(cache);
+    host2->AssociateCache(cache);
+
+    // Give the newest cache a master entry that is also one of the explicit
+    // entries in the manifest.
+    cache->AddEntry(http_server_->TestServerPage("files/explicit1"),
+                    AppCacheEntry(AppCacheEntry::MASTER));
+
+    // TODO(jennb): simulate this by mocking storage behavior instead
+    update->SimulateManifestChanged(true);  // changed
+
+    update->StartUpdate(NULL, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = false;
+    expect_group_has_cache_ = true;
+    expect_old_cache_ = cache;
+    tested_manifest_ = MANIFEST_MERGED_TYPES;
+    MockFrontend::HostIds ids1(1, host1->host_id());
+    frontend1->AddExpectedEvent(ids1, CHECKING_EVENT);
+    frontend1->AddExpectedEvent(ids1, DOWNLOADING_EVENT);
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);  // explicit1 (load)
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);  // explicit1 (fetch)
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);  // manifest
+    frontend1->AddExpectedEvent(ids1, UPDATE_READY_EVENT);
+    MockFrontend::HostIds ids2(1, host2->host_id());
+    frontend2->AddExpectedEvent(ids2, CHECKING_EVENT);
+    frontend2->AddExpectedEvent(ids2, DOWNLOADING_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, UPDATE_READY_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void CacheAttemptFailUrlFetchTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(
+      service_.get(), http_server_->TestServerPage("files/manifest-with-404"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    MockFrontend* frontend = MakeMockFrontend();
+    AppCacheHost* host = MakeHost(1, frontend);
+    update->StartUpdate(host, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = false;
+    expect_group_has_cache_ = false;  // 404 explicit url is cache failure
+    frontend->AddExpectedEvent(MockFrontend::HostIds(1, host->host_id()),
+                               CHECKING_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void UpgradeFailUrlFetchTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(
+      service_.get(), http_server_->TestServerPage("files/manifest-fb-404"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    AppCache* cache = MakeCacheForGroup(service_->NewCacheId());
+    MockFrontend* frontend1 = MakeMockFrontend();
+    MockFrontend* frontend2 = MakeMockFrontend();
+    AppCacheHost* host1 = MakeHost(1, frontend1);
+    AppCacheHost* host2 = MakeHost(2, frontend2);
+    host1->AssociateCache(cache);
+    host2->AssociateCache(cache);
+
+    // TODO(jennb): simulate this by mocking storage behavior instead
+    update->SimulateManifestChanged(true);  // changed
+
+    update->StartUpdate(NULL, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = false;
+    expect_group_has_cache_ = true;
+    expect_newest_cache_ = cache;  // newest cache unaffectd by failed update
+    MockFrontend::HostIds ids1(1, host1->host_id());
+    frontend1->AddExpectedEvent(ids1, CHECKING_EVENT);
+    frontend1->AddExpectedEvent(ids1, DOWNLOADING_EVENT);
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);
+    frontend1->AddExpectedEvent(ids1, ERROR_EVENT);
+    MockFrontend::HostIds ids2(1, host2->host_id());
+    frontend2->AddExpectedEvent(ids2, CHECKING_EVENT);
+    frontend2->AddExpectedEvent(ids2, DOWNLOADING_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, ERROR_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void UpgradeFailMasterUrlFetchTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(
+        service_.get(), http_server_->TestServerPage("files/manifest1"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    AppCache* cache = MakeCacheForGroup(service_->NewCacheId());
+    MockFrontend* frontend1 = MakeMockFrontend();
+    MockFrontend* frontend2 = MakeMockFrontend();
+    AppCacheHost* host1 = MakeHost(1, frontend1);
+    AppCacheHost* host2 = MakeHost(2, frontend2);
+    host1->AssociateCache(cache);
+    host2->AssociateCache(cache);
+
+    // Give the newest cache some master entries; one will fail with a 404.
+    cache->AddEntry(
+        http_server_->TestServerPage("files/notfound"),
+        AppCacheEntry(AppCacheEntry::MASTER));
+    cache->AddEntry(
+        http_server_->TestServerPage("files/explicit2"),
+        AppCacheEntry(AppCacheEntry::MASTER | AppCacheEntry::FOREIGN));
+    cache->AddEntry(
+        http_server_->TestServerPage("files/servererror"),
+        AppCacheEntry(AppCacheEntry::MASTER));
+
+    // TODO(jennb): simulate this by mocking storage behavior instead
+    update->SimulateManifestChanged(true);  // changed
+
+    update->StartUpdate(NULL, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = false;
+    expect_group_has_cache_ = true;
+    expect_old_cache_ = cache;
+    tested_manifest_ = MANIFEST1;
+    expect_extra_entries_.insert(AppCache::EntryMap::value_type(
+        http_server_->TestServerPage("files/explicit2"),
+        AppCacheEntry(AppCacheEntry::MASTER)));  // foreign flag is dropped
+    expect_extra_entries_.insert(AppCache::EntryMap::value_type(
+        http_server_->TestServerPage("files/servererror"),
+        AppCacheEntry(AppCacheEntry::MASTER)));  // foreign flag is dropped
+    MockFrontend::HostIds ids1(1, host1->host_id());
+    frontend1->AddExpectedEvent(ids1, CHECKING_EVENT);
+    frontend1->AddExpectedEvent(ids1, DOWNLOADING_EVENT);
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);  // explicit1
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);  // fallback1a
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);  // notfound (load)
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);  // notfound (fetch)
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);  // explicit2 (load)
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);  // explicit2 (fetch)
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);  // servererror (load)
+    frontend1->AddExpectedEvent(ids1, PROGRESS_EVENT);  // servererror (fetch)
+    frontend1->AddExpectedEvent(ids1, UPDATE_READY_EVENT);
+    MockFrontend::HostIds ids2(1, host2->host_id());
+    frontend2->AddExpectedEvent(ids2, CHECKING_EVENT);
+    frontend2->AddExpectedEvent(ids2, DOWNLOADING_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, PROGRESS_EVENT);
+    frontend2->AddExpectedEvent(ids2, UPDATE_READY_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void EmptyManifestTest() {
+    ASSERT_EQ(MessageLoop::TYPE_IO, MessageLoop::current()->type());
+
+    MakeService();
+    group_ = new AppCacheGroup(
+        service_.get(), http_server_->TestServerPage("files/empty-manifest"));
+    AppCacheUpdateJob* update = new AppCacheUpdateJob(service_.get(), group_);
+    group_->update_job_ = update;
+
+    AppCache* cache = MakeCacheForGroup(service_->NewCacheId());
+    MockFrontend* frontend1 = MakeMockFrontend();
+    MockFrontend* frontend2 = MakeMockFrontend();
+    AppCacheHost* host1 = MakeHost(1, frontend1);
+    AppCacheHost* host2 = MakeHost(2, frontend2);
+    host1->AssociateCache(cache);
+    host2->AssociateCache(cache);
+
+    // TODO(jennb): simulate this by mocking storage behavior instead
+    update->SimulateManifestChanged(true);  // changed
+
+    update->StartUpdate(NULL, GURL::EmptyGURL());
+    EXPECT_TRUE(update->manifest_url_request_ != NULL);
+
+    // Set up checks for when update job finishes.
+    do_checks_after_update_finished_ = true;
+    expect_group_obsolete_ = false;
+    expect_group_has_cache_ = true;
+    expect_old_cache_ = cache;
+    tested_manifest_ = EMPTY_MANIFEST;
+    MockFrontend::HostIds ids1(1, host1->host_id());
+    frontend1->AddExpectedEvent(ids1, CHECKING_EVENT);
+    frontend1->AddExpectedEvent(ids1, DOWNLOADING_EVENT);
+    frontend1->AddExpectedEvent(ids1, UPDATE_READY_EVENT);
+    MockFrontend::HostIds ids2(1, host2->host_id());
+    frontend2->AddExpectedEvent(ids2, CHECKING_EVENT);
+    frontend2->AddExpectedEvent(ids2, DOWNLOADING_EVENT);
+    frontend2->AddExpectedEvent(ids2, UPDATE_READY_EVENT);
+
+    WaitForUpdateToFinish();
+  }
+
+  void WaitForUpdateToFinish() {
+    if (group_->update_status() == AppCacheGroup::IDLE)
+      UpdateFinished();
+    else
+      group_->AddObserver(this);
+  }
+
+  void OnUpdateComplete(AppCacheGroup* group) {
+    ASSERT_EQ(group_, group);
+
+    // Finish up outside of observer callback so that group can be deleted.
+    MessageLoop::current()->PostTask(FROM_HERE,
+        method_factory_.NewRunnableMethod(
+            &AppCacheUpdateJobTest::UpdateFinished));
+  }
+
+  void UpdateFinished() {
+    EXPECT_EQ(AppCacheGroup::IDLE, group_->update_status());
+    EXPECT_TRUE(group_->update_job() == NULL);
+    if (do_checks_after_update_finished_)
+      VerifyExpectations();
+
+    // Clean up everything that was created on the IO thread.
+    group_ = NULL;
+    STLDeleteContainerPointers(hosts_.begin(), hosts_.end());
+    STLDeleteContainerPointers(frontends_.begin(), frontends_.end());
+    service_.reset(NULL);
+    URLRequest::RegisterProtocolFactory("http", NULL);
+
+    event_->Signal();
+  }
+
+  void MakeService() {
+    service_.reset(new AppCacheService());
+    request_context_ = new TestURLRequestContext();
+    service_->set_request_context(request_context_);
+  }
+
+  AppCache* MakeCacheForGroup(int64 cache_id) {
+    AppCache* cache = new AppCache(service_.get(), cache_id);
+    cache->set_complete(true);
+    cache->set_update_time(base::TimeTicks::Now());
+    cache->set_owning_group(group_);
+    group_->AddCache(cache);
+    return cache;
+  }
+
+  AppCacheHost* MakeHost(int host_id, AppCacheFrontend* frontend) {
+    AppCacheHost* host = new AppCacheHost(host_id, frontend, service_.get());
+    hosts_.push_back(host);
+    return host;
+  }
+
+  MockFrontend* MakeMockFrontend() {
+    MockFrontend* frontend = new MockFrontend();
+    frontends_.push_back(frontend);
+    return frontend;
+  }
+
+  // Verifies conditions about the group and notifications after an update
+  // has finished. Cannot verify update job internals as update is deleted.
+  void VerifyExpectations() {
+    EXPECT_EQ(expect_group_obsolete_, group_->is_obsolete());
+
+    if (expect_group_has_cache_) {
+      EXPECT_TRUE(group_->newest_complete_cache() != NULL);
+      if (expect_old_cache_) {
+        EXPECT_NE(expect_old_cache_, group_->newest_complete_cache());
+        EXPECT_TRUE(group_->old_caches().end() !=
+            std::find(group_->old_caches().begin(),
+                      group_->old_caches().end(), expect_old_cache_));
+      }
+      if (expect_newest_cache_)
+        EXPECT_EQ(expect_newest_cache_, group_->newest_complete_cache());
+      switch (tested_manifest_) {
+        case MANIFEST1:
+          VerifyManifest1(group_->newest_complete_cache());
+          break;
+        case MANIFEST_MERGED_TYPES:
+          VerifyManifestMergedTypes(group_->newest_complete_cache());
+          break;
+        case EMPTY_MANIFEST:
+          VerifyEmptyManifest(group_->newest_complete_cache());
+          break;
+        case NONE:
+        default:
+          break;
+      }
+    } else {
+      EXPECT_TRUE(group_->newest_complete_cache() == NULL);
+    }
+
+    // Check expected events.
+    for (size_t i = 0; i < frontends_.size(); ++i) {
+      MockFrontend* frontend = frontends_[i];
+
+      MockFrontend::RaisedEvents& expected_events = frontend->expected_events_;
+      MockFrontend::RaisedEvents& actual_events = frontend->raised_events_;
+      EXPECT_EQ(expected_events.size(), actual_events.size());
+
+      // Check each expected event.
+      for (size_t j = 0;
+           j < expected_events.size() && j < actual_events.size(); ++j) {
+        EXPECT_EQ(expected_events[j].second, actual_events[j].second);
+
+        MockFrontend::HostIds& expected_ids = expected_events[j].first;
+        MockFrontend::HostIds& actual_ids = actual_events[j].first;
+        EXPECT_EQ(expected_ids.size(), actual_ids.size());
+
+        for (size_t k = 0; k < expected_ids.size(); ++k) {
+          int id = expected_ids[k];
+          EXPECT_TRUE(std::find(actual_ids.begin(), actual_ids.end(), id) !=
+              actual_ids.end());
+        }
+      }
+    }
+  }
+
+  void VerifyManifest1(AppCache* cache) {
+    ASSERT_TRUE(cache != NULL);
+    EXPECT_EQ(group_, cache->owning_group());
+    EXPECT_TRUE(cache->is_complete());
+
+    size_t expected = 3 + expect_extra_entries_.size();
+    EXPECT_EQ(expected, cache->entries().size());
+    AppCacheEntry* entry =
+        cache->GetEntry(http_server_->TestServerPage("files/manifest1"));
+    ASSERT_TRUE(entry);
+    EXPECT_EQ(AppCacheEntry::MANIFEST, entry->types());
+    entry = cache->GetEntry(http_server_->TestServerPage("files/explicit1"));
+    ASSERT_TRUE(entry);
+    EXPECT_EQ(AppCacheEntry::EXPLICIT, entry->types());
+    entry = cache->GetEntry(
+        http_server_->TestServerPage("files/fallback1a"));
+    ASSERT_TRUE(entry);
+    EXPECT_EQ(AppCacheEntry::FALLBACK, entry->types());
+
+    for (AppCache::EntryMap::iterator i = expect_extra_entries_.begin();
+         i != expect_extra_entries_.end(); ++i) {
+      entry = cache->GetEntry(i->first);
+      ASSERT_TRUE(entry);
+      EXPECT_EQ(i->second.types(), entry->types());
+      // TODO(jennb): if copied, check storage id in entry is as expected
+    }
+
+    expected = 1;
+    EXPECT_EQ(expected, cache->fallback_namespaces_.size());
+    EXPECT_TRUE(cache->fallback_namespaces_.end() !=
+        std::find(cache->fallback_namespaces_.begin(),
+                  cache->fallback_namespaces_.end(),
+                  FallbackNamespace(
+                      http_server_->TestServerPage("files/fallback1"),
+                      http_server_->TestServerPage("files/fallback1a"))));
+
+    EXPECT_TRUE(cache->online_whitelist_namespaces_.empty());
+    EXPECT_TRUE(cache->online_whitelist_all_);
+
+    EXPECT_TRUE(cache->update_time_ > base::TimeTicks());
+  }
+
+  void VerifyManifestMergedTypes(AppCache* cache) {
+    ASSERT_TRUE(cache != NULL);
+    EXPECT_EQ(group_, cache->owning_group());
+    EXPECT_TRUE(cache->is_complete());
+
+    size_t expected = 2;
+    EXPECT_EQ(expected, cache->entries().size());
+    AppCacheEntry* entry = cache->GetEntry(
+        http_server_->TestServerPage("files/manifest-merged-types"));
+    ASSERT_TRUE(entry);
+    EXPECT_EQ(AppCacheEntry::EXPLICIT | AppCacheEntry::MANIFEST,
+              entry->types());
+    entry = cache->GetEntry(http_server_->TestServerPage("files/explicit1"));
+    ASSERT_TRUE(entry);
+    EXPECT_EQ(AppCacheEntry::EXPLICIT | AppCacheEntry::FALLBACK |
+        AppCacheEntry::MASTER, entry->types());
+
+    expected = 1;
+    EXPECT_EQ(expected, cache->fallback_namespaces_.size());
+    EXPECT_TRUE(cache->fallback_namespaces_.end() !=
+        std::find(cache->fallback_namespaces_.begin(),
+                  cache->fallback_namespaces_.end(),
+                  FallbackNamespace(
+                      http_server_->TestServerPage("files/fallback1"),
+                      http_server_->TestServerPage("files/explicit1"))));
+
+    EXPECT_EQ(expected, cache->online_whitelist_namespaces_.size());
+    EXPECT_TRUE(cache->online_whitelist_namespaces_.end() !=
+        std::find(cache->online_whitelist_namespaces_.begin(),
+                  cache->online_whitelist_namespaces_.end(),
+                  http_server_->TestServerPage("files/online1")));
+    EXPECT_FALSE(cache->online_whitelist_all_);
+
+    EXPECT_TRUE(cache->update_time_ > base::TimeTicks());
+  }
+
+  void VerifyEmptyManifest(AppCache* cache) {
+    ASSERT_TRUE(cache!= NULL);
+    EXPECT_EQ(group_, cache->owning_group());
+    EXPECT_TRUE(cache->is_complete());
+
+    size_t expected = 1;
+    EXPECT_EQ(expected, cache->entries().size());
+    AppCacheEntry* entry = cache->GetEntry(
+        http_server_->TestServerPage("files/empty-manifest"));
+    ASSERT_TRUE(entry);
+    EXPECT_EQ(AppCacheEntry::MANIFEST, entry->types());
+
+    EXPECT_TRUE(cache->fallback_namespaces_.empty());
+    EXPECT_TRUE(cache->online_whitelist_namespaces_.empty());
+    EXPECT_FALSE(cache->online_whitelist_all_);
+
+    EXPECT_TRUE(cache->update_time_ > base::TimeTicks());
+  }
+
+ private:
+  // Various manifest files used in this test.
+  enum TestedManifest {
+    NONE,
+    MANIFEST1,
+    MANIFEST_MERGED_TYPES,
+    EMPTY_MANIFEST,
+  };
+
+  static scoped_ptr<base::Thread> io_thread_;
+  static scoped_refptr<HTTPTestServer> http_server_;
+
+  ScopedRunnableMethodFactory<AppCacheUpdateJobTest> method_factory_;
+  scoped_ptr<AppCacheService> service_;
+  scoped_refptr<TestURLRequestContext> request_context_;
+  scoped_refptr<AppCacheGroup> group_;
+  scoped_ptr<base::WaitableEvent> event_;
+
+  // Hosts used by an async test that need to live until update job finishes.
+  // Otherwise, test can put host on the stack instead of here.
+  std::vector<AppCacheHost*> hosts_;
+
+  // Flag indicating if test cares to verify the update after update finishes.
+  bool do_checks_after_update_finished_;
+  bool expect_group_obsolete_;
+  bool expect_group_has_cache_;
+  AppCache* expect_old_cache_;
+  AppCache* expect_newest_cache_;
+  std::vector<MockFrontend*> frontends_;  // to check expected events
+  TestedManifest tested_manifest_;
+  AppCache::EntryMap expect_extra_entries_;
+};
+
+// static
+scoped_ptr<base::Thread> AppCacheUpdateJobTest::io_thread_;
+scoped_refptr<HTTPTestServer> AppCacheUpdateJobTest::http_server_;
+
+TEST_F(AppCacheUpdateJobTest, AlreadyChecking) {
+  AppCacheService service;
+  scoped_refptr<AppCacheGroup> group =
+      new AppCacheGroup(&service, GURL("http://manifesturl.com"));
+
+  AppCacheUpdateJob update(&service, group);
+
+  // Pretend group is in checking state.
+  group->update_job_ = &update;
+  group->update_status_ = AppCacheGroup::CHECKING;
+
+  update.StartUpdate(NULL, GURL::EmptyGURL());
+  EXPECT_EQ(AppCacheGroup::CHECKING, group->update_status());
+
+  MockFrontend mock_frontend;
+  AppCacheHost host(1, &mock_frontend, &service);
+  update.StartUpdate(&host, GURL::EmptyGURL());
+
+  MockFrontend::RaisedEvents events = mock_frontend.raised_events_;
+  size_t expected = 1;
+  EXPECT_EQ(expected, events.size());
+  EXPECT_EQ(expected, events[0].first.size());
+  EXPECT_EQ(host.host_id(), events[0].first[0]);
+  EXPECT_EQ(CHECKING_EVENT, events[0].second);
+  EXPECT_EQ(AppCacheGroup::CHECKING, group->update_status());
+}
+
+TEST_F(AppCacheUpdateJobTest, AlreadyDownloading) {
+  AppCacheService service;
+  scoped_refptr<AppCacheGroup> group =
+      new AppCacheGroup(&service, GURL("http://manifesturl.com"));
+
+  AppCacheUpdateJob update(&service, group);
+
+  // Pretend group is in downloading state.
+  group->update_job_ = &update;
+  group->update_status_ = AppCacheGroup::DOWNLOADING;
+
+  update.StartUpdate(NULL, GURL::EmptyGURL());
+  EXPECT_EQ(AppCacheGroup::DOWNLOADING, group->update_status());
+
+  MockFrontend mock_frontend;
+  AppCacheHost host(1, &mock_frontend, &service);
+  update.StartUpdate(&host, GURL::EmptyGURL());
+
+  MockFrontend::RaisedEvents events = mock_frontend.raised_events_;
+  size_t expected = 2;
+  EXPECT_EQ(expected, events.size());
+  expected = 1;
+  EXPECT_EQ(expected, events[0].first.size());
+  EXPECT_EQ(host.host_id(), events[0].first[0]);
+  EXPECT_EQ(CHECKING_EVENT, events[0].second);
+
+  EXPECT_EQ(expected, events[1].first.size());
+  EXPECT_EQ(host.host_id(), events[1].first[0]);
+  EXPECT_EQ(appcache::DOWNLOADING_EVENT, events[1].second);
+
+  EXPECT_EQ(AppCacheGroup::DOWNLOADING, group->update_status());
+}
+
+TEST_F(AppCacheUpdateJobTest, StartCacheAttempt) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::StartCacheAttemptTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, StartUpgradeAttempt) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::StartUpgradeAttemptTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, CacheAttemptFetchManifestFail) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::CacheAttemptFetchManifestFailTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, UpgradeFetchManifestFail) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::UpgradeFetchManifestFailTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, ManifestRedirect) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::ManifestRedirectTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, ManifestWrongMimeType) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::ManifestWrongMimeTypeTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, ManifestNotFound) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::ManifestNotFoundTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, ManifestGone) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::ManifestGoneTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, CacheAttemptNotModified) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::CacheAttemptNotModifiedTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, UpgradeNotModified) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::UpgradeNotModifiedTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, UpgradeManifestDataUnchanged) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::UpgradeManifestDataUnchangedTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, BasicCacheAttemptSuccess) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::BasicCacheAttemptSuccessTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, BasicUpgradeSuccess) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::BasicUpgradeSuccessTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, UpgradeSuccessMergedTypes) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::UpgradeSuccessMergedTypesTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, CacheAttemptFailUrlFetch) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::CacheAttemptFailUrlFetchTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, UpgradeFailUrlFetch) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::UpgradeFailUrlFetchTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, UpgradeFailMasterUrlFetch) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::UpgradeFailMasterUrlFetchTest);
+}
+
+TEST_F(AppCacheUpdateJobTest, EmptyManifest) {
+  RunTestOnIOThread(&AppCacheUpdateJobTest::EmptyManifestTest);
+}
+
+}  // namespace appcache
diff --git a/webkit/appcache/data/appcache_unittest/empty-manifest b/webkit/appcache/data/appcache_unittest/empty-manifest
new file mode 100644
index 0000000..af16a0e
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/empty-manifest
@@ -0,0 +1 @@
+CACHE MANIFEST
diff --git a/webkit/appcache/data/appcache_unittest/empty-manifest.mock-http-headers b/webkit/appcache/data/appcache_unittest/empty-manifest.mock-http-headers
new file mode 100644
index 0000000..6e904b9
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/empty-manifest.mock-http-headers
@@ -0,0 +1,2 @@
+HTTP/1.1 200 OK
+Content-type: text/cache-manifest
diff --git a/webkit/appcache/data/appcache_unittest/explicit1 b/webkit/appcache/data/appcache_unittest/explicit1
new file mode 100644
index 0000000..33e739e
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/explicit1
@@ -0,0 +1 @@
+explicit1
diff --git a/webkit/appcache/data/appcache_unittest/explicit2 b/webkit/appcache/data/appcache_unittest/explicit2
new file mode 100644
index 0000000..2128ad6
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/explicit2
@@ -0,0 +1 @@
+explicit2
diff --git a/webkit/appcache/data/appcache_unittest/fallback1a b/webkit/appcache/data/appcache_unittest/fallback1a
new file mode 100644
index 0000000..62cd309
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/fallback1a
@@ -0,0 +1 @@
+fallback1a
diff --git a/webkit/appcache/data/appcache_unittest/gone b/webkit/appcache/data/appcache_unittest/gone
new file mode 100644
index 0000000..97896a0
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/gone
@@ -0,0 +1 @@
+nothing
\ No newline at end of file
diff --git a/webkit/appcache/data/appcache_unittest/gone.mock-http-headers b/webkit/appcache/data/appcache_unittest/gone.mock-http-headers
new file mode 100644
index 0000000..2817c70
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/gone.mock-http-headers
@@ -0,0 +1 @@
+HTTP/1.1 410 GONE
diff --git a/webkit/appcache/data/appcache_unittest/manifest-fb-404 b/webkit/appcache/data/appcache_unittest/manifest-fb-404
new file mode 100644
index 0000000..aea2364
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/manifest-fb-404
@@ -0,0 +1,7 @@
+CACHE MANIFEST
+explicit1
+FALLBACK:
+fallback404 fallback-404
+fallback1 fallback1a
+NETWORK:
+online1
diff --git a/webkit/appcache/data/appcache_unittest/manifest-fb-404.mock-http-headers b/webkit/appcache/data/appcache_unittest/manifest-fb-404.mock-http-headers
new file mode 100644
index 0000000..6e904b9
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/manifest-fb-404.mock-http-headers
@@ -0,0 +1,2 @@
+HTTP/1.1 200 OK
+Content-type: text/cache-manifest
diff --git a/webkit/appcache/data/appcache_unittest/manifest-merged-types b/webkit/appcache/data/appcache_unittest/manifest-merged-types
new file mode 100644
index 0000000..5c6589b
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/manifest-merged-types
@@ -0,0 +1,9 @@
+CACHE MANIFEST
+explicit1
+# manifest is also an explicit entry
+manifest-merged-types
+FALLBACK:
+# fallback is also explicit entry
+fallback1 explicit1
+NETWORK:
+online1
diff --git a/webkit/appcache/data/appcache_unittest/manifest-merged-types.mock-http-headers b/webkit/appcache/data/appcache_unittest/manifest-merged-types.mock-http-headers
new file mode 100644
index 0000000..6e904b9
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/manifest-merged-types.mock-http-headers
@@ -0,0 +1,2 @@
+HTTP/1.1 200 OK
+Content-type: text/cache-manifest
diff --git a/webkit/appcache/data/appcache_unittest/manifest-with-404 b/webkit/appcache/data/appcache_unittest/manifest-with-404
new file mode 100644
index 0000000..353fad7
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/manifest-with-404
@@ -0,0 +1,9 @@
+CACHE MANIFEST
+explicit-404
+explicit1
+explicit2
+explicit3
+FALLBACK:
+fallback1 fallback1a
+NETWORK:
+online1
diff --git a/webkit/appcache/data/appcache_unittest/manifest-with-404.mock-http-headers b/webkit/appcache/data/appcache_unittest/manifest-with-404.mock-http-headers
new file mode 100644
index 0000000..6e904b9
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/manifest-with-404.mock-http-headers
@@ -0,0 +1,2 @@
+HTTP/1.1 200 OK
+Content-type: text/cache-manifest
diff --git a/webkit/appcache/data/appcache_unittest/manifest1 b/webkit/appcache/data/appcache_unittest/manifest1
new file mode 100644
index 0000000..b33fad5
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/manifest1
@@ -0,0 +1,6 @@
+CACHE MANIFEST
+explicit1
+FALLBACK:
+fallback1 fallback1a
+NETWORK:
+*
diff --git a/webkit/appcache/data/appcache_unittest/manifest1.mock-http-headers b/webkit/appcache/data/appcache_unittest/manifest1.mock-http-headers
new file mode 100644
index 0000000..6e904b9
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/manifest1.mock-http-headers
@@ -0,0 +1,2 @@
+HTTP/1.1 200 OK
+Content-type: text/cache-manifest
diff --git a/webkit/appcache/data/appcache_unittest/notmodified b/webkit/appcache/data/appcache_unittest/notmodified
new file mode 100644
index 0000000..b3f1762
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/notmodified
@@ -0,0 +1 @@
+nochange
\ No newline at end of file
diff --git a/webkit/appcache/data/appcache_unittest/notmodified.mock-http-headers b/webkit/appcache/data/appcache_unittest/notmodified.mock-http-headers
new file mode 100644
index 0000000..b86db0d
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/notmodified.mock-http-headers
@@ -0,0 +1 @@
+HTTP/1.1 304 NOT MODIFIED
diff --git a/webkit/appcache/data/appcache_unittest/servererror b/webkit/appcache/data/appcache_unittest/servererror
new file mode 100644
index 0000000..760589c
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/servererror
@@ -0,0 +1 @@
+error
\ No newline at end of file
diff --git a/webkit/appcache/data/appcache_unittest/servererror.mock-http-headers b/webkit/appcache/data/appcache_unittest/servererror.mock-http-headers
new file mode 100644
index 0000000..472aa4b
--- /dev/null
+++ b/webkit/appcache/data/appcache_unittest/servererror.mock-http-headers
@@ -0,0 +1 @@
+HTTP/1.1 500 INTERNAL SERVER ERROR
diff --git a/webkit/tools/test_shell/test_shell.gyp b/webkit/tools/test_shell/test_shell.gyp
index 5124764..5a3d5a8 100644
--- a/webkit/tools/test_shell/test_shell.gyp
+++ b/webkit/tools/test_shell/test_shell.gyp
@@ -361,6 +361,7 @@
         '../../appcache/appcache_group_unittest.cc',
         '../../appcache/appcache_host_unittest.cc',
         '../../appcache/appcache_service_unittest.cc',
+        '../../appcache/appcache_update_job_unittest.cc',
         '../../glue/bookmarklet_unittest.cc',
         '../../glue/context_menu_unittest.cc',
         '../../glue/cpp_bound_class_unittest.cc',
diff --git a/webkit/webkit.gyp b/webkit/webkit.gyp
index 2dd6bba..7bb9705 100644
--- a/webkit/webkit.gyp
+++ b/webkit/webkit.gyp
@@ -406,6 +406,8 @@
         'appcache/appcache_request_handler.h',
         'appcache/appcache_service.cc',
         'appcache/appcache_service.h',
+        'appcache/appcache_update_job.cc',
+        'appcache/appcache_update_job.h',
         'appcache/manifest_parser.cc',
         'appcache/manifest_parser.h',
         'appcache/web_application_cache_host_impl.cc',