ServiceWorker: Move worker candidate process knowledge to ServiceWorkerProcessManager.

Before this CL:
Candidate processes info is saved in EmbeddedWorkerInstance, when a new
worker instance is created for a same scope, the info will be absent for
the new worker. E.g., periodic update will spawn a new process every time.

After this CL:
Candidate processes info will be saved in  ServiceWorkerProcessManager
key by registration scope. Then different versions with the same scope could
share this info.

BUG=399982
TEST=content_unittests --gtest_filter=ServiceWorker*

Review URL: https://codereview.chromium.org/443593002

Cr-Commit-Position: refs/heads/master@{#294113}

27 files changed, 354 insertions, 361 deletions

diff --git a/content/browser/service_worker/embedded_worker_instance.cc b/content/browser/service_worker/embedded_worker_instance.cc
index 7cf0f18..ee909a5 100644
--- a/content/browser/service_worker/embedded_worker_instance.cc
+++ b/content/browser/service_worker/embedded_worker_instance.cc
@@ -127,7 +127,6 @@ void EmbeddedWorkerInstance::Start(int64 service_worker_version_id,
                                    const GURL& scope,
                                    const GURL& script_url,
                                    bool pause_after_download,
-                                   const std::vector<int>& possible_process_ids,
                                    const StatusCallback& callback) {
   if (!context_) {
     callback.Run(SERVICE_WORKER_ERROR_ABORT);
@@ -151,7 +150,7 @@ void EmbeddedWorkerInstance::Start(int64 service_worker_version_id,
   params->wait_for_debugger = false;
   context_->process_manager()->AllocateWorkerProcess(
       embedded_worker_id_,
-      SortProcesses(possible_process_ids),
+      scope,
       script_url,
       base::Bind(&EmbeddedWorkerInstance::RunProcessAllocated,
                  weak_factory_.GetWeakPtr(),
@@ -186,23 +185,6 @@ ServiceWorkerStatusCode EmbeddedWorkerInstance::SendMessage(
                              thread_id_, embedded_worker_id_, message));
 }
 
-void EmbeddedWorkerInstance::AddProcessReference(int process_id) {
-  ProcessRefMap::iterator found = process_refs_.find(process_id);
-  if (found == process_refs_.end())
-    found = process_refs_.insert(std::make_pair(process_id, 0)).first;
-  ++found->second;
-}
-
-void EmbeddedWorkerInstance::ReleaseProcessReference(int process_id) {
-  ProcessRefMap::iterator found = process_refs_.find(process_id);
-  if (found == process_refs_.end()) {
-    NOTREACHED() << "Releasing unknown process ref " << process_id;
-    return;
-  }
-  if (--found->second == 0)
-    process_refs_.erase(found);
-}
-
 EmbeddedWorkerInstance::EmbeddedWorkerInstance(
     base::WeakPtr<ServiceWorkerContextCore> context,
     int embedded_worker_id)
@@ -366,26 +348,4 @@ void EmbeddedWorkerInstance::RemoveListener(Listener* listener) {
   listener_list_.RemoveObserver(listener);
 }
 
-std::vector<int> EmbeddedWorkerInstance::SortProcesses(
-    const std::vector<int>& possible_process_ids) const {
-  // Add the |possible_process_ids| to the existing process_refs_ since each one
-  // is likely to take a reference once the SW starts up.
-  ProcessRefMap refs_with_new_ids = process_refs_;
-  for (std::vector<int>::const_iterator it = possible_process_ids.begin();
-       it != possible_process_ids.end();
-       ++it) {
-    refs_with_new_ids[*it]++;
-  }
-
-  std::vector<std::pair<int, int> > counted(refs_with_new_ids.begin(),
-                                            refs_with_new_ids.end());
-  // Sort descending by the reference count.
-  std::sort(counted.begin(), counted.end(), SecondGreater());
-
-  std::vector<int> result(counted.size());
-  for (size_t i = 0; i < counted.size(); ++i)
-    result[i] = counted[i].first;
-  return result;
-}
-
 }  // namespace content
diff --git a/content/browser/service_worker/embedded_worker_instance.h b/content/browser/service_worker/embedded_worker_instance.h
index 9abde46..510e72b 100644
--- a/content/browser/service_worker/embedded_worker_instance.h
+++ b/content/browser/service_worker/embedded_worker_instance.h
@@ -76,7 +76,6 @@ class CONTENT_EXPORT EmbeddedWorkerInstance {
              const GURL& scope,
              const GURL& script_url,
              bool pause_after_download,
-             const std::vector<int>& possible_process_ids,
              const StatusCallback& callback);
 
   // Stops the worker. It is invalid to call this when the worker is
@@ -91,12 +90,6 @@ class CONTENT_EXPORT EmbeddedWorkerInstance {
 
   void ResumeAfterDownload();
 
-  // Add or remove |process_id| to the internal process set where this
-  // worker can be started.
-  void AddProcessReference(int process_id);
-  void ReleaseProcessReference(int process_id);
-  bool HasProcessToRun() const { return !process_refs_.empty(); }
-
   int embedded_worker_id() const { return embedded_worker_id_; }
   Status status() const { return status_; }
   int process_id() const { return process_id_; }
@@ -113,9 +106,6 @@ class CONTENT_EXPORT EmbeddedWorkerInstance {
 
   friend class EmbeddedWorkerRegistry;
   FRIEND_TEST_ALL_PREFIXES(EmbeddedWorkerInstanceTest, StartAndStop);
-  FRIEND_TEST_ALL_PREFIXES(EmbeddedWorkerInstanceTest, SortProcesses);
-
-  typedef std::map<int, int> ProcessRefMap;
 
   // Constructor is called via EmbeddedWorkerRegistry::CreateWorker().
   // This instance holds a ref of |registry|.
@@ -185,11 +175,6 @@ class CONTENT_EXPORT EmbeddedWorkerInstance {
                               int line_number,
                               const GURL& source_url);
 
-  // Chooses a list of processes to try to start this worker in, ordered by how
-  // many clients are currently in those processes.
-  std::vector<int> SortProcesses(
-      const std::vector<int>& possible_process_ids) const;
-
   base::WeakPtr<ServiceWorkerContextCore> context_;
   scoped_refptr<EmbeddedWorkerRegistry> registry_;
   const int embedded_worker_id_;
@@ -200,7 +185,6 @@ class CONTENT_EXPORT EmbeddedWorkerInstance {
   int thread_id_;
   int worker_devtools_agent_route_id_;
 
-  ProcessRefMap process_refs_;
   ListenerList listener_list_;
 
   base::WeakPtrFactory<EmbeddedWorkerInstance> weak_factory_;
diff --git a/content/browser/service_worker/embedded_worker_instance_unittest.cc b/content/browser/service_worker/embedded_worker_instance_unittest.cc
index 7f1fcca..be2fb59 100644
--- a/content/browser/service_worker/embedded_worker_instance_unittest.cc
+++ b/content/browser/service_worker/embedded_worker_instance_unittest.cc
@@ -60,23 +60,21 @@ TEST_F(EmbeddedWorkerInstanceTest, StartAndStop) {
       embedded_worker_registry()->CreateWorker();
   EXPECT_EQ(EmbeddedWorkerInstance::STOPPED, worker->status());
 
-  const int embedded_worker_id = worker->embedded_worker_id();
   const int64 service_worker_version_id = 55L;
-  const GURL scope("http://example.com/");
+  const GURL pattern("http://example.com/");
   const GURL url("http://example.com/worker.js");
 
-  // Simulate adding one process to the worker.
-  helper_->SimulateAddProcessToWorker(embedded_worker_id, kRenderProcessId);
+  // Simulate adding one process to the pattern.
+  helper_->SimulateAddProcessToPattern(pattern, kRenderProcessId);
 
   // Start should succeed.
   ServiceWorkerStatusCode status;
   base::RunLoop run_loop;
   worker->Start(
       service_worker_version_id,
-      scope,
+      pattern,
       url,
       false,
-      std::vector<int>(),
       base::Bind(&SaveStatusAndCall, &status, run_loop.QuitClosure()));
   run_loop.Run();
   EXPECT_EQ(SERVICE_WORKER_OK, status);
@@ -108,20 +106,19 @@ TEST_F(EmbeddedWorkerInstanceTest, InstanceDestroyedBeforeStartFinishes) {
   EXPECT_EQ(EmbeddedWorkerInstance::STOPPED, worker->status());
 
   const int64 service_worker_version_id = 55L;
-  const GURL scope("http://example.com/");
+  const GURL pattern("http://example.com/");
   const GURL url("http://example.com/worker.js");
 
   ServiceWorkerStatusCode status;
   base::RunLoop run_loop;
   // Begin starting the worker.
-  std::vector<int> available_process;
-  available_process.push_back(kRenderProcessId);
+  context()->process_manager()->AddProcessReferenceToPattern(
+      pattern, kRenderProcessId);
   worker->Start(
       service_worker_version_id,
-      scope,
+      pattern,
       url,
       false,
-      available_process,
       base::Bind(&SaveStatusAndCall, &status, run_loop.QuitClosure()));
   // But destroy it before it gets a chance to complete.
   worker.reset();
@@ -133,38 +130,4 @@ TEST_F(EmbeddedWorkerInstanceTest, InstanceDestroyedBeforeStartFinishes) {
       ipc_sink()->GetUniqueMessageMatching(EmbeddedWorkerMsg_StartWorker::ID));
 }
 
-TEST_F(EmbeddedWorkerInstanceTest, SortProcesses) {
-  scoped_ptr<EmbeddedWorkerInstance> worker =
-      embedded_worker_registry()->CreateWorker();
-  EXPECT_EQ(EmbeddedWorkerInstance::STOPPED, worker->status());
-
-  // Simulate adding processes to the worker.
-  // Process 1 has 1 ref, 2 has 2 refs and 3 has 3 refs.
-  const int embedded_worker_id = worker->embedded_worker_id();
-  helper_->SimulateAddProcessToWorker(embedded_worker_id, 1);
-  helper_->SimulateAddProcessToWorker(embedded_worker_id, 2);
-  helper_->SimulateAddProcessToWorker(embedded_worker_id, 2);
-  helper_->SimulateAddProcessToWorker(embedded_worker_id, 3);
-  helper_->SimulateAddProcessToWorker(embedded_worker_id, 3);
-  helper_->SimulateAddProcessToWorker(embedded_worker_id, 3);
-
-  // Process 3 has the biggest # of references and it should be chosen.
-  EXPECT_THAT(worker->SortProcesses(std::vector<int>()),
-              testing::ElementsAre(3, 2, 1));
-  EXPECT_EQ(-1, worker->process_id());
-
-  // Argument processes are added to the existing set, but only for a single
-  // call.
-  std::vector<int> registering_processes;
-  registering_processes.push_back(1);
-  registering_processes.push_back(1);
-  registering_processes.push_back(1);
-  registering_processes.push_back(4);
-  EXPECT_THAT(worker->SortProcesses(registering_processes),
-              testing::ElementsAre(1, 3, 2, 4));
-
-  EXPECT_THAT(worker->SortProcesses(std::vector<int>()),
-              testing::ElementsAre(3, 2, 1));
-}
-
 }  // namespace content
diff --git a/content/browser/service_worker/embedded_worker_test_helper.cc b/content/browser/service_worker/embedded_worker_test_helper.cc
index b0f05c7..97adcf1 100644
--- a/content/browser/service_worker/embedded_worker_test_helper.cc
+++ b/content/browser/service_worker/embedded_worker_test_helper.cc
@@ -37,13 +37,12 @@ EmbeddedWorkerTestHelper::~EmbeddedWorkerTestHelper() {
     wrapper_->Shutdown();
 }
 
-void EmbeddedWorkerTestHelper::SimulateAddProcessToWorker(
-    int embedded_worker_id,
+void EmbeddedWorkerTestHelper::SimulateAddProcessToPattern(
+    const GURL& pattern,
     int process_id) {
-  EmbeddedWorkerInstance* worker = registry()->GetWorker(embedded_worker_id);
-  ASSERT_TRUE(worker);
   registry()->AddChildProcessSender(process_id, this);
-  worker->AddProcessReference(process_id);
+  wrapper_->process_manager()->AddProcessReferenceToPattern(
+      pattern, process_id);
 }
 
 bool EmbeddedWorkerTestHelper::Send(IPC::Message* message) {
diff --git a/content/browser/service_worker/embedded_worker_test_helper.h b/content/browser/service_worker/embedded_worker_test_helper.h
index 0034b5c..c36773d 100644
--- a/content/browser/service_worker/embedded_worker_test_helper.h
+++ b/content/browser/service_worker/embedded_worker_test_helper.h
@@ -48,9 +48,9 @@ class EmbeddedWorkerTestHelper : public IPC::Sender,
   explicit EmbeddedWorkerTestHelper(int mock_render_process_id);
   virtual ~EmbeddedWorkerTestHelper();
 
-  // Call this to simulate add/associate a process to a worker.
+  // Call this to simulate add/associate a process to a pattern.
   // This also registers this sender for the process.
-  void SimulateAddProcessToWorker(int embedded_worker_id, int process_id);
+  void SimulateAddProcessToPattern(const GURL& pattern, int process_id);
 
   // IPC::Sender implementation.
   virtual bool Send(IPC::Message* message) OVERRIDE;
diff --git a/content/browser/service_worker/service_worker_browsertest.cc b/content/browser/service_worker/service_worker_browsertest.cc
index 6355340..8ad27e9 100644
--- a/content/browser/service_worker/service_worker_browsertest.cc
+++ b/content/browser/service_worker/service_worker_browsertest.cc
@@ -294,9 +294,9 @@ class ServiceWorkerBrowserTest : public ContentBrowserTest {
   ServiceWorkerContextWrapper* wrapper() { return wrapper_.get(); }
   ServiceWorkerContext* public_context() { return wrapper(); }
 
-  void AssociateRendererProcessToWorker(EmbeddedWorkerInstance* worker) {
-    worker->AddProcessReference(
-        shell()->web_contents()->GetRenderProcessHost()->GetID());
+  void AssociateRendererProcessToPattern(const GURL& pattern) {
+    wrapper_->process_manager()->AddProcessReferenceToPattern(
+        pattern, shell()->web_contents()->GetRenderProcessHost()->GetID());
   }
 
  private:
@@ -326,21 +326,20 @@ class EmbeddedWorkerBrowserTest : public ServiceWorkerBrowserTest,
     EXPECT_EQ(EmbeddedWorkerInstance::STOPPED, worker_->status());
     worker_->AddListener(this);
 
-    AssociateRendererProcessToWorker(worker_.get());
 
     const int64 service_worker_version_id = 33L;
-    const GURL scope = embedded_test_server()->GetURL("/");
+    const GURL pattern = embedded_test_server()->GetURL("/");
     const GURL script_url = embedded_test_server()->GetURL(
         "/service_worker/worker.js");
-    std::vector<int> processes;
-    processes.push_back(
-        shell()->web_contents()->GetRenderProcessHost()->GetID());
+    AssociateRendererProcessToPattern(pattern);
+    int process_id = shell()->web_contents()->GetRenderProcessHost()->GetID();
+    wrapper()->process_manager()->AddProcessReferenceToPattern(
+        pattern, process_id);
     worker_->Start(
         service_worker_version_id,
-        scope,
+        pattern,
         script_url,
         pause_mode_ != DONT_PAUSE,
-        processes,
         base::Bind(&EmbeddedWorkerBrowserTest::StartOnIOThread2, this));
   }
   void StartOnIOThread2(ServiceWorkerStatusCode status) {
@@ -503,8 +502,9 @@ class ServiceWorkerVersionBrowserTest : public ServiceWorkerBrowserTest {
   }
 
   void SetUpRegistrationOnIOThread(const std::string& worker_url) {
+    const GURL pattern = embedded_test_server()->GetURL("/");
     registration_ = new ServiceWorkerRegistration(
-        embedded_test_server()->GetURL("/"),
+        pattern,
         wrapper()->context()->storage()->NewRegistrationId(),
         wrapper()->context()->AsWeakPtr());
     version_ = new ServiceWorkerVersion(
@@ -512,7 +512,7 @@ class ServiceWorkerVersionBrowserTest : public ServiceWorkerBrowserTest {
         embedded_test_server()->GetURL(worker_url),
         wrapper()->context()->storage()->NewVersionId(),
         wrapper()->context()->AsWeakPtr());
-    AssociateRendererProcessToWorker(version_->embedded_worker());
+    AssociateRendererProcessToPattern(pattern);
   }
 
   void StartOnIOThread(const base::Closure& done,
diff --git a/content/browser/service_worker/service_worker_context_core.cc b/content/browser/service_worker/service_worker_context_core.cc
index 5647ef9..4615f8e 100644
--- a/content/browser/service_worker/service_worker_context_core.cc
+++ b/content/browser/service_worker/service_worker_context_core.cc
@@ -175,7 +175,6 @@ ServiceWorkerContextCore::GetProviderHostIterator() {
 void ServiceWorkerContextCore::RegisterServiceWorker(
     const GURL& pattern,
     const GURL& script_url,
-    int source_process_id,
     ServiceWorkerProviderHost* provider_host,
     const RegistrationCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
@@ -186,13 +185,10 @@ void ServiceWorkerContextCore::RegisterServiceWorker(
     return;
   }
 
-  // TODO(kinuko): Wire the provider_host so that we can tell which document
-  // is calling .register.
-
   job_coordinator_->Register(
       pattern,
       script_url,
-      source_process_id,
+      provider_host,
       base::Bind(&ServiceWorkerContextCore::RegistrationComplete,
                  AsWeakPtr(),
                  pattern,
@@ -408,7 +404,9 @@ void ServiceWorkerContextCore::OnReportConsoleMessage(
 }
 
 ServiceWorkerProcessManager* ServiceWorkerContextCore::process_manager() {
-  return wrapper_->process_manager();
+  if (wrapper_)
+    return wrapper_->process_manager();
+  return NULL;
 }
 
 }  // namespace content
diff --git a/content/browser/service_worker/service_worker_context_core.h b/content/browser/service_worker/service_worker_context_core.h
index d3d9898..83ef2f6 100644
--- a/content/browser/service_worker/service_worker_context_core.h
+++ b/content/browser/service_worker/service_worker_context_core.h
@@ -145,11 +145,9 @@ class CONTENT_EXPORT ServiceWorkerContextCore
 
   // A child process of |source_process_id| may be used to run the created
   // worker for initial installation.
-  // Non-null |provider_host| must be given if this is called from a document,
-  // whose process_id() must match with |source_process_id|.
+  // Non-null |provider_host| must be given if this is called from a document.
   void RegisterServiceWorker(const GURL& pattern,
                              const GURL& script_url,
-                             int source_process_id,
                              ServiceWorkerProviderHost* provider_host,
                              const RegistrationCallback& callback);
   void UnregisterServiceWorker(const GURL& pattern,
diff --git a/content/browser/service_worker/service_worker_context_unittest.cc b/content/browser/service_worker/service_worker_context_unittest.cc
index ad550f8..0fb2fb9 100644
--- a/content/browser/service_worker/service_worker_context_unittest.cc
+++ b/content/browser/service_worker/service_worker_context_unittest.cc
@@ -144,7 +144,6 @@ TEST_F(ServiceWorkerContextTest, Register) {
   context()->RegisterServiceWorker(
       GURL("http://www.example.com/"),
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
       NULL,
       MakeRegisteredCallback(&called, &registration_id, &version_id));
 
@@ -187,7 +186,6 @@ TEST_F(ServiceWorkerContextTest, Register_RejectInstall) {
   context()->RegisterServiceWorker(
       GURL("http://www.example.com/"),
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
       NULL,
       MakeRegisteredCallback(&called, &registration_id, &version_id));
 
@@ -230,7 +228,6 @@ TEST_F(ServiceWorkerContextTest, Register_RejectActivate) {
   context()->RegisterServiceWorker(
       GURL("http://www.example.com/"),
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
       NULL,
       MakeRegisteredCallback(&called, &registration_id, &version_id));
 
@@ -271,7 +268,6 @@ TEST_F(ServiceWorkerContextTest, Unregister) {
   context()->RegisterServiceWorker(
       pattern,
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
       NULL,
       MakeRegisteredCallback(&called, &registration_id, &version_id));
 
@@ -311,7 +307,6 @@ TEST_F(ServiceWorkerContextTest, RegisterNewScript) {
   context()->RegisterServiceWorker(
       pattern,
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
       NULL,
       MakeRegisteredCallback(&called, &old_registration_id, &old_version_id));
 
@@ -327,7 +322,6 @@ TEST_F(ServiceWorkerContextTest, RegisterNewScript) {
   context()->RegisterServiceWorker(
       pattern,
       GURL("http://www.example.com/service_worker_new.js"),
-      render_process_id_,
       NULL,
       MakeRegisteredCallback(&called, &new_registration_id, &new_version_id));
 
@@ -353,7 +347,6 @@ TEST_F(ServiceWorkerContextTest, RegisterDuplicateScript) {
   context()->RegisterServiceWorker(
       pattern,
       script_url,
-      render_process_id_,
       NULL,
       MakeRegisteredCallback(&called, &old_registration_id, &old_version_id));
 
@@ -369,7 +362,6 @@ TEST_F(ServiceWorkerContextTest, RegisterDuplicateScript) {
   context()->RegisterServiceWorker(
       pattern,
       script_url,
-      render_process_id_,
       NULL,
       MakeRegisteredCallback(&called, &new_registration_id, &new_version_id));
 
@@ -388,7 +380,6 @@ TEST_F(ServiceWorkerContextTest, DeleteAndStartOver) {
   context()->RegisterServiceWorker(
       GURL("http://www.example.com/"),
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
       NULL,
       MakeRegisteredCallback(&called, &registration_id, &version_id));
 
@@ -436,7 +427,6 @@ TEST_F(ServiceWorkerContextTest, DeleteAndStartOver) {
   context()->RegisterServiceWorker(
       GURL("http://www.example.com/"),
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
       NULL,
       MakeRegisteredCallback(&called, &registration_id, &version_id));
 
diff --git a/content/browser/service_worker/service_worker_context_wrapper.cc b/content/browser/service_worker/service_worker_context_wrapper.cc
index c21e459..bedf37e 100644
--- a/content/browser/service_worker/service_worker_context_wrapper.cc
+++ b/content/browser/service_worker/service_worker_context_wrapper.cc
@@ -106,7 +106,6 @@ void ServiceWorkerContextWrapper::RegisterServiceWorker(
   context()->RegisterServiceWorker(
       pattern,
       script_url,
-      -1,
       NULL /* provider_host */,
       base::Bind(&FinishRegistrationOnIO, continuation));
 }
diff --git a/content/browser/service_worker/service_worker_dispatcher_host.cc b/content/browser/service_worker/service_worker_dispatcher_host.cc
index a0bdabf..42e2ae1 100644
--- a/content/browser/service_worker/service_worker_dispatcher_host.cc
+++ b/content/browser/service_worker/service_worker_dispatcher_host.cc
@@ -245,7 +245,6 @@ void ServiceWorkerDispatcherHost::OnRegisterServiceWorker(
   GetContext()->RegisterServiceWorker(
       pattern,
       script_url,
-      render_process_id_,
       provider_host,
       base::Bind(&ServiceWorkerDispatcherHost::RegistrationComplete,
                  this,
diff --git a/content/browser/service_worker/service_worker_handle_unittest.cc b/content/browser/service_worker/service_worker_handle_unittest.cc
index 75b3016..3368dc1 100644
--- a/content/browser/service_worker/service_worker_handle_unittest.cc
+++ b/content/browser/service_worker/service_worker_handle_unittest.cc
@@ -46,8 +46,9 @@ class ServiceWorkerHandleTest : public testing::Test {
   virtual void SetUp() OVERRIDE {
     helper_.reset(new EmbeddedWorkerTestHelper(kRenderProcessId));
 
+    const GURL pattern("http://www.example.com/");
     registration_ = new ServiceWorkerRegistration(
-        GURL("http://www.example.com/"),
+        pattern,
         1L,
         helper_->context()->AsWeakPtr());
     version_ = new ServiceWorkerVersion(
@@ -56,9 +57,7 @@ class ServiceWorkerHandleTest : public testing::Test {
         1L,
         helper_->context()->AsWeakPtr());
 
-    // Simulate adding one process to the worker.
-    int embedded_worker_id = version_->embedded_worker()->embedded_worker_id();
-    helper_->SimulateAddProcessToWorker(embedded_worker_id, kRenderProcessId);
+    helper_->SimulateAddProcessToPattern(pattern, kRenderProcessId);
   }
 
   virtual void TearDown() OVERRIDE {
diff --git a/content/browser/service_worker/service_worker_job_coordinator.cc b/content/browser/service_worker/service_worker_job_coordinator.cc
index e5e8962..c3bfb39 100644
--- a/content/browser/service_worker/service_worker_job_coordinator.cc
+++ b/content/browser/service_worker/service_worker_job_coordinator.cc
@@ -71,14 +71,14 @@ ServiceWorkerJobCoordinator::~ServiceWorkerJobCoordinator() {
 void ServiceWorkerJobCoordinator::Register(
     const GURL& pattern,
     const GURL& script_url,
-    int source_process_id,
+    ServiceWorkerProviderHost* provider_host,
     const ServiceWorkerRegisterJob::RegistrationCallback& callback) {
   scoped_ptr<ServiceWorkerRegisterJobBase> job(
       new ServiceWorkerRegisterJob(context_, pattern, script_url));
   ServiceWorkerRegisterJob* queued_job =
       static_cast<ServiceWorkerRegisterJob*>(
           job_queues_[pattern].Push(job.Pass()));
-  queued_job->AddCallback(callback, source_process_id);
+  queued_job->AddCallback(callback, provider_host);
 }
 
 void ServiceWorkerJobCoordinator::Unregister(
diff --git a/content/browser/service_worker/service_worker_job_coordinator.h b/content/browser/service_worker/service_worker_job_coordinator.h
index fa33562..b85a84b 100644
--- a/content/browser/service_worker/service_worker_job_coordinator.h
+++ b/content/browser/service_worker/service_worker_job_coordinator.h
@@ -16,6 +16,7 @@
 namespace content {
 
 class EmbeddedWorkerRegistry;
+class ServiceWorkerProviderHost;
 class ServiceWorkerRegistration;
 class ServiceWorkerStorage;
 
@@ -28,7 +29,7 @@ class CONTENT_EXPORT ServiceWorkerJobCoordinator {
 
   void Register(const GURL& pattern,
                 const GURL& script_url,
-                int source_process_id,
+                ServiceWorkerProviderHost* provider_host,
                 const ServiceWorkerRegisterJob::RegistrationCallback& callback);
 
   void Unregister(
diff --git a/content/browser/service_worker/service_worker_job_unittest.cc b/content/browser/service_worker/service_worker_job_unittest.cc
index 8793169..2cda8e0 100644
--- a/content/browser/service_worker/service_worker_job_unittest.cc
+++ b/content/browser/service_worker/service_worker_job_unittest.cc
@@ -132,7 +132,7 @@ TEST_F(ServiceWorkerJobTest, SameDocumentSameRegistration) {
   job_coordinator()->Register(
       GURL("http://www.example.com/"),
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &called, &original_registration));
   EXPECT_FALSE(called);
   base::RunLoop().RunUntilIdle();
@@ -159,7 +159,7 @@ TEST_F(ServiceWorkerJobTest, SameMatchSameRegistration) {
   job_coordinator()->Register(
       GURL("http://www.example.com/"),
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &called, &original_registration));
   EXPECT_FALSE(called);
   base::RunLoop().RunUntilIdle();
@@ -190,7 +190,7 @@ TEST_F(ServiceWorkerJobTest, DifferentMatchDifferentRegistration) {
   job_coordinator()->Register(
       GURL("http://www.example.com/one/"),
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &called1, &original_registration1));
 
   bool called2;
@@ -198,7 +198,7 @@ TEST_F(ServiceWorkerJobTest, DifferentMatchDifferentRegistration) {
   job_coordinator()->Register(
       GURL("http://www.example.com/two/"),
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &called2, &original_registration2));
 
   EXPECT_FALSE(called1);
@@ -229,7 +229,7 @@ TEST_F(ServiceWorkerJobTest, Register) {
   job_coordinator()->Register(
       GURL("http://www.example.com/"),
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &called, &registration));
 
   ASSERT_FALSE(called);
@@ -248,7 +248,7 @@ TEST_F(ServiceWorkerJobTest, Unregister) {
   job_coordinator()->Register(
       pattern,
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &called, &registration));
 
   ASSERT_FALSE(called);
@@ -298,7 +298,7 @@ TEST_F(ServiceWorkerJobTest, RegisterNewScript) {
   job_coordinator()->Register(
       pattern,
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &called, &old_registration));
 
   ASSERT_FALSE(called);
@@ -322,7 +322,7 @@ TEST_F(ServiceWorkerJobTest, RegisterNewScript) {
   job_coordinator()->Register(
       pattern,
       GURL("http://www.example.com/service_worker_new.js"),
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &called, &new_registration));
 
   ASSERT_FALSE(called);
@@ -355,7 +355,7 @@ TEST_F(ServiceWorkerJobTest, RegisterDuplicateScript) {
   job_coordinator()->Register(
       pattern,
       script_url,
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &called, &old_registration));
 
   ASSERT_FALSE(called);
@@ -377,7 +377,7 @@ TEST_F(ServiceWorkerJobTest, RegisterDuplicateScript) {
   job_coordinator()->Register(
       pattern,
       script_url,
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &called, &new_registration));
 
   ASSERT_FALSE(called);
@@ -424,7 +424,7 @@ TEST_F(ServiceWorkerJobTest, Register_FailToStartWorker) {
   job_coordinator()->Register(
       GURL("http://www.example.com/"),
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
+      NULL,
       SaveRegistration(
           SERVICE_WORKER_ERROR_START_WORKER_FAILED, &called, &registration));
 
@@ -446,7 +446,7 @@ TEST_F(ServiceWorkerJobTest, ParallelRegUnreg) {
   job_coordinator()->Register(
       pattern,
       script_url,
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &registration_called, &registration));
 
   bool unregistration_called = false;
@@ -483,7 +483,7 @@ TEST_F(ServiceWorkerJobTest, ParallelRegNewScript) {
   job_coordinator()->Register(
       pattern,
       script_url1,
-      render_process_id_,
+      NULL,
       SaveRegistration(
           SERVICE_WORKER_OK, &registration1_called, &registration1));
 
@@ -493,7 +493,7 @@ TEST_F(ServiceWorkerJobTest, ParallelRegNewScript) {
   job_coordinator()->Register(
       pattern,
       script_url2,
-      render_process_id_,
+      NULL,
       SaveRegistration(
           SERVICE_WORKER_OK, &registration2_called, &registration2));
 
@@ -527,7 +527,7 @@ TEST_F(ServiceWorkerJobTest, ParallelRegSameScript) {
   job_coordinator()->Register(
       pattern,
       script_url,
-      render_process_id_,
+      NULL,
       SaveRegistration(
           SERVICE_WORKER_OK, &registration1_called, &registration1));
 
@@ -536,7 +536,7 @@ TEST_F(ServiceWorkerJobTest, ParallelRegSameScript) {
   job_coordinator()->Register(
       pattern,
       script_url,
-      render_process_id_,
+      NULL,
       SaveRegistration(
           SERVICE_WORKER_OK, &registration2_called, &registration2));
 
@@ -604,7 +604,7 @@ TEST_F(ServiceWorkerJobTest, AbortAll_Register) {
   job_coordinator()->Register(
       pattern1,
       script_url1,
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_ERROR_ABORT,
                        &registration_called1, &registration1));
 
@@ -613,7 +613,7 @@ TEST_F(ServiceWorkerJobTest, AbortAll_Register) {
   job_coordinator()->Register(
       pattern2,
       script_url2,
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_ERROR_ABORT,
                        &registration_called2, &registration2));
 
@@ -679,7 +679,7 @@ TEST_F(ServiceWorkerJobTest, AbortAll_RegUnreg) {
   job_coordinator()->Register(
       pattern,
       script_url,
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_ERROR_ABORT,
                        &registration_called, &registration));
 
@@ -717,7 +717,7 @@ TEST_F(ServiceWorkerJobTest, UnregisterWaitingSetsRedundant) {
   job_coordinator()->Register(
       GURL("http://www.example.com/"),
       script_url,
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &called, &registration));
   base::RunLoop().RunUntilIdle();
   ASSERT_TRUE(called);
@@ -758,7 +758,7 @@ TEST_F(ServiceWorkerJobTest, UnregisterActiveSetsRedundant) {
   job_coordinator()->Register(
       GURL("http://www.example.com/"),
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &called, &registration));
   base::RunLoop().RunUntilIdle();
   ASSERT_TRUE(called);
@@ -789,7 +789,7 @@ TEST_F(ServiceWorkerJobTest,
   job_coordinator()->Register(
       GURL("http://www.example.com/"),
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &called, &registration));
   base::RunLoop().RunUntilIdle();
   ASSERT_TRUE(called);
@@ -913,7 +913,7 @@ class UpdateJobTestHelper
     job_coordinator()->Register(
         test_origin.Resolve(kScope),
         test_origin.Resolve(kScript),
-        mock_render_process_id(),
+        NULL,
         SaveRegistration(SERVICE_WORKER_OK, &called, &registration));
     base::RunLoop().RunUntilIdle();
     EXPECT_TRUE(called);
@@ -1128,7 +1128,7 @@ TEST_F(ServiceWorkerJobTest, Update_NewestVersionChanged) {
   job_coordinator()->Register(
       GURL("http://www.example.com/one/"),
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &called, &registration));
 
   EXPECT_FALSE(called);
@@ -1161,7 +1161,7 @@ TEST_F(ServiceWorkerJobTest, Update_UninstallingRegistration) {
   job_coordinator()->Register(
       GURL("http://www.example.com/one/"),
       GURL("http://www.example.com/service_worker.js"),
-      render_process_id_,
+      NULL,
       SaveRegistration(SERVICE_WORKER_OK, &called, &registration));
 
   EXPECT_FALSE(called);
diff --git a/content/browser/service_worker/service_worker_process_manager.cc b/content/browser/service_worker/service_worker_process_manager.cc
index ab6012a..16e585b 100644
--- a/content/browser/service_worker/service_worker_process_manager.cc
+++ b/content/browser/service_worker/service_worker_process_manager.cc
@@ -12,6 +12,18 @@
 
 namespace content {
 
+namespace {
+
+// Functor to sort by the .second element of a struct.
+struct SecondGreater {
+  template <typename Value>
+  bool operator()(const Value& lhs, const Value& rhs) {
+    return lhs.second > rhs.second;
+  }
+};
+
+}  // namespace
+
 static bool IncrementWorkerRefCountByPid(int process_id) {
   RenderProcessHost* rph = RenderProcessHost::FromID(process_id);
   if (!rph || rph->FastShutdownStarted())
@@ -61,9 +73,66 @@ void ServiceWorkerProcessManager::Shutdown() {
   instance_info_.clear();
 }
 
+void ServiceWorkerProcessManager::AddProcessReferenceToPattern(
+    const GURL& pattern, int process_id) {
+  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
+    BrowserThread::PostTask(
+        BrowserThread::UI,
+        FROM_HERE,
+        base::Bind(&ServiceWorkerProcessManager::AddProcessReferenceToPattern,
+                   weak_this_,
+                   pattern,
+                   process_id));
+    return;
+  }
+
+  ProcessRefMap& process_refs = pattern_processes_[pattern];
+  ++process_refs[process_id];
+}
+
+void ServiceWorkerProcessManager::RemoveProcessReferenceFromPattern(
+    const GURL& pattern, int process_id) {
+  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
+    BrowserThread::PostTask(
+        BrowserThread::UI,
+        FROM_HERE,
+        base::Bind(
+          &ServiceWorkerProcessManager::RemoveProcessReferenceFromPattern,
+          weak_this_,
+          pattern,
+          process_id));
+    return;
+  }
+
+  PatternProcessRefMap::iterator it = pattern_processes_.find(pattern);
+  if (it == pattern_processes_.end()) {
+    NOTREACHED() << "process refrences not found for pattern: " << pattern;
+    return;
+  }
+  ProcessRefMap& process_refs = it->second;
+  ProcessRefMap::iterator found = process_refs.find(process_id);
+  if (found == process_refs.end()) {
+    NOTREACHED() << "Releasing unknown process ref " << process_id;
+    return;
+  }
+  if (--found->second == 0) {
+    process_refs.erase(found);
+    if (process_refs.empty())
+      pattern_processes_.erase(it);
+  }
+}
+
+bool ServiceWorkerProcessManager::PatternHasProcessToRun(
+    const GURL& pattern) const {
+  PatternProcessRefMap::const_iterator it = pattern_processes_.find(pattern);
+  if (it == pattern_processes_.end())
+    return false;
+  return !it->second.empty();
+}
+
 void ServiceWorkerProcessManager::AllocateWorkerProcess(
     int embedded_worker_id,
-    const std::vector<int>& process_ids,
+    const GURL& pattern,
     const GURL& script_url,
     const base::Callback<void(ServiceWorkerStatusCode, int process_id)>&
         callback) {
@@ -74,7 +143,7 @@ void ServiceWorkerProcessManager::AllocateWorkerProcess(
         base::Bind(&ServiceWorkerProcessManager::AllocateWorkerProcess,
                    weak_this_,
                    embedded_worker_id,
-                   process_ids,
+                   pattern,
                    script_url,
                    callback));
     return;
@@ -93,17 +162,18 @@ void ServiceWorkerProcessManager::AllocateWorkerProcess(
   DCHECK(!ContainsKey(instance_info_, embedded_worker_id))
       << embedded_worker_id << " already has a process allocated";
 
-  for (std::vector<int>::const_iterator it = process_ids.begin();
-       it != process_ids.end();
+  std::vector<int> sorted_candidates = SortProcessesForPattern(pattern);
+  for (std::vector<int>::const_iterator it = sorted_candidates.begin();
+       it != sorted_candidates.end();
        ++it) {
-    if (IncrementWorkerRefCountByPid(*it)) {
-      instance_info_.insert(
-          std::make_pair(embedded_worker_id, ProcessInfo(*it)));
-      BrowserThread::PostTask(BrowserThread::IO,
-                              FROM_HERE,
-                              base::Bind(callback, SERVICE_WORKER_OK, *it));
-      return;
-    }
+    if (!IncrementWorkerRefCountByPid(*it))
+      continue;
+    instance_info_.insert(
+        std::make_pair(embedded_worker_id, ProcessInfo(*it)));
+    BrowserThread::PostTask(BrowserThread::IO,
+                            FROM_HERE,
+                            base::Bind(callback, SERVICE_WORKER_OK, *it));
+    return;
   }
 
   if (!browser_context_) {
@@ -179,6 +249,22 @@ void ServiceWorkerProcessManager::ReleaseWorkerProcess(int embedded_worker_id) {
   instance_info_.erase(info);
 }
 
+std::vector<int> ServiceWorkerProcessManager::SortProcessesForPattern(
+    const GURL& pattern) const {
+  PatternProcessRefMap::const_iterator it = pattern_processes_.find(pattern);
+  if (it == pattern_processes_.end())
+    return std::vector<int>();
+
+  std::vector<std::pair<int, int> > counted(
+      it->second.begin(), it->second.end());
+  std::sort(counted.begin(), counted.end(), SecondGreater());
+
+  std::vector<int> result(counted.size());
+  for (size_t i = 0; i < counted.size(); ++i)
+    result[i] = counted[i].first;
+  return result;
+}
+
 }  // namespace content
 
 namespace base {
diff --git a/content/browser/service_worker/service_worker_process_manager.h b/content/browser/service_worker/service_worker_process_manager.h
index 85fbcc1..edfef42 100644
--- a/content/browser/service_worker/service_worker_process_manager.h
+++ b/content/browser/service_worker/service_worker_process_manager.h
@@ -9,6 +9,7 @@
 #include <vector>
 
 #include "base/callback.h"
+#include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "content/common/service_worker/service_worker_status_code.h"
@@ -21,9 +22,9 @@ class BrowserContext;
 class SiteInstance;
 
 // Interacts with the UI thread to keep RenderProcessHosts alive while the
-// ServiceWorker system is using them. Each instance of
-// ServiceWorkerProcessManager is destroyed on the UI thread shortly after its
-// ServiceWorkerContextWrapper is destroyed.
+// ServiceWorker system is using them. It also tracks candidate processes
+// for each pattern. Each instance of ServiceWorkerProcessManager is destroyed
+// on the UI thread shortly after its ServiceWorkerContextWrapper is destroyed.
 class CONTENT_EXPORT ServiceWorkerProcessManager {
  public:
   // |*this| must be owned by a ServiceWorkerContextWrapper in a
@@ -38,16 +39,14 @@ class CONTENT_EXPORT ServiceWorkerProcessManager {
   void Shutdown();
 
   // Returns a reference to a running process suitable for starting the Service
-  // Worker at |script_url|. Processes in |process_ids| will be checked in order
-  // for existence, and if none exist, then a new process will be created. Posts
-  // |callback| to the IO thread to indicate whether creation succeeded and the
-  // process ID that has a new reference.
+  // Worker at |script_url|. Posts |callback| to the IO thread to indicate
+  // whether creation succeeded and the process ID that has a new reference.
   //
   // Allocation can fail with SERVICE_WORKER_ERROR_START_WORKER_FAILED if
   // RenderProcessHost::Init fails.
   void AllocateWorkerProcess(
       int embedded_worker_id,
-      const std::vector<int>& process_ids,
+      const GURL& pattern,
       const GURL& script_url,
       const base::Callback<void(ServiceWorkerStatusCode, int process_id)>&
           callback);
@@ -65,7 +64,17 @@ class CONTENT_EXPORT ServiceWorkerProcessManager {
     process_id_for_test_ = process_id;
   }
 
+  // Adds/removes process reference for the |pattern|, the process with highest
+  // references count will be chosen to start a worker.
+  void AddProcessReferenceToPattern(const GURL& pattern, int process_id);
+  void RemoveProcessReferenceFromPattern(const GURL& pattern, int process_id);
+
+  // Returns true if the |pattern| has at least one process to run.
+  bool PatternHasProcessToRun(const GURL& pattern) const;
+
  private:
+  FRIEND_TEST_ALL_PREFIXES(ServiceWorkerProcessManagerTest, SortProcess);
+
   // Information about the process for an EmbeddedWorkerInstance.
   struct ProcessInfo {
     explicit ProcessInfo(const scoped_refptr<SiteInstance>& site_instance);
@@ -84,6 +93,15 @@ class CONTENT_EXPORT ServiceWorkerProcessManager {
     int process_id;
   };
 
+  // Maps the process ID to its reference count.
+  typedef std::map<int, int> ProcessRefMap;
+
+  // Maps registration scope pattern to ProcessRefMap.
+  typedef std::map<const GURL, ProcessRefMap> PatternProcessRefMap;
+
+  // Returns a process vector sorted by the reference count for the |pattern|.
+  std::vector<int> SortProcessesForPattern(const GURL& pattern) const;
+
   // These fields are only accessed on the UI thread.
   BrowserContext* browser_context_;
 
@@ -100,6 +118,10 @@ class CONTENT_EXPORT ServiceWorkerProcessManager {
   // EmbeddedWorkerInstances.
   int process_id_for_test_;
 
+  // Candidate processes info for each pattern, should be accessed on the
+  // UI thread.
+  PatternProcessRefMap pattern_processes_;
+
   // Used to double-check that we don't access *this after it's destroyed.
   base::WeakPtrFactory<ServiceWorkerProcessManager> weak_this_factory_;
   const base::WeakPtr<ServiceWorkerProcessManager> weak_this_;
diff --git a/content/browser/service_worker/service_worker_process_manager_unittest.cc b/content/browser/service_worker/service_worker_process_manager_unittest.cc
new file mode 100644
index 0000000..aedc1eb
--- /dev/null
+++ b/content/browser/service_worker/service_worker_process_manager_unittest.cc
@@ -0,0 +1,56 @@
+// Copyright 2014 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 "base/basictypes.h"
+#include "content/browser/service_worker/service_worker_process_manager.h"
+#include "content/public/test/test_browser_thread_bundle.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "url/gurl.h"
+
+namespace content {
+
+class ServiceWorkerProcessManagerTest : public testing::Test {
+ public:
+  ServiceWorkerProcessManagerTest() {}
+
+  virtual void SetUp() OVERRIDE {
+    process_manager_.reset(new ServiceWorkerProcessManager(NULL));
+    pattern_ = GURL("http://www.example.com/");
+  }
+
+  virtual void TearDown() OVERRIDE {
+    process_manager_.reset();
+  }
+
+ protected:
+  scoped_ptr<ServiceWorkerProcessManager> process_manager_;
+  GURL pattern_;
+
+ private:
+  content::TestBrowserThreadBundle thread_bundle_;
+  DISALLOW_COPY_AND_ASSIGN(ServiceWorkerProcessManagerTest);
+};
+
+TEST_F(ServiceWorkerProcessManagerTest, SortProcess) {
+  // Process 1 has 2 ref, 2 has 3 refs and 3 has 1 refs.
+  process_manager_->AddProcessReferenceToPattern(pattern_, 1);
+  process_manager_->AddProcessReferenceToPattern(pattern_, 1);
+  process_manager_->AddProcessReferenceToPattern(pattern_, 2);
+  process_manager_->AddProcessReferenceToPattern(pattern_, 2);
+  process_manager_->AddProcessReferenceToPattern(pattern_, 2);
+  process_manager_->AddProcessReferenceToPattern(pattern_, 3);
+
+  // Process 2 has the biggest # of references and it should be chosen.
+  EXPECT_THAT(process_manager_->SortProcessesForPattern(pattern_),
+              testing::ElementsAre(2, 1, 3));
+
+  process_manager_->RemoveProcessReferenceFromPattern(pattern_, 1);
+  process_manager_->RemoveProcessReferenceFromPattern(pattern_, 1);
+  // Scores for each process: 2 : 3, 3 : 1, process 1 is removed.
+  EXPECT_THAT(process_manager_->SortProcessesForPattern(pattern_),
+              testing::ElementsAre(2, 3));
+}
+
+}  // namespace content
diff --git a/content/browser/service_worker/service_worker_provider_host.cc b/content/browser/service_worker/service_worker_provider_host.cc
index bd0c5ea..4cc054a 100644
--- a/content/browser/service_worker/service_worker_provider_host.cc
+++ b/content/browser/service_worker/service_worker_provider_host.cc
@@ -37,14 +37,14 @@ ServiceWorkerProviderHost::~ServiceWorkerProviderHost() {
   document_url_ = GURL();
   if (controlling_version_.get())
     controlling_version_->RemoveControllee(this);
-  if (active_version_.get())
-    active_version_->RemovePotentialControllee(this);
-  if (waiting_version_.get())
-    waiting_version_->RemovePotentialControllee(this);
-  if (installing_version_.get())
-    installing_version_->RemovePotentialControllee(this);
-  if (associated_registration_.get())
+  if (associated_registration_.get()) {
+    DecreaseProcessReference(associated_registration_->pattern());
     associated_registration_->RemoveListener(this);
+  }
+  for (std::vector<GURL>::iterator it = associated_patterns_.begin();
+       it != associated_patterns_.end(); ++it) {
+    DecreaseProcessReference(*it);
+  }
 }
 
 void ServiceWorkerProviderHost::OnVersionAttributesChanged(
@@ -52,9 +52,9 @@ void ServiceWorkerProviderHost::OnVersionAttributesChanged(
     ChangedVersionAttributesMask changed_mask,
     const ServiceWorkerRegistrationInfo& info) {
   DCHECK_EQ(associated_registration_.get(), registration);
-  UpdatePotentialControllees(registration->installing_version(),
-                             registration->waiting_version(),
-                             registration->active_version());
+  installing_version_ = registration->installing_version();
+  waiting_version_ = registration->waiting_version();
+  active_version_ = registration->active_version();
 }
 
 void ServiceWorkerProviderHost::OnRegistrationFailed(
@@ -68,38 +68,6 @@ void ServiceWorkerProviderHost::SetDocumentUrl(const GURL& url) {
   document_url_ = url;
 }
 
-void ServiceWorkerProviderHost::UpdatePotentialControllees(
-    ServiceWorkerVersion* installing_version,
-    ServiceWorkerVersion* waiting_version,
-    ServiceWorkerVersion* active_version) {
-   if (installing_version != installing_version_.get()) {
-     scoped_refptr<ServiceWorkerVersion> previous_version = installing_version_;
-     if (previous_version.get())
-       previous_version->RemovePotentialControllee(this);
-     if (installing_version)
-       installing_version->AddPotentialControllee(this);
-     installing_version_ = installing_version;
-   }
-
-   if (waiting_version != waiting_version_.get()) {
-     scoped_refptr<ServiceWorkerVersion> previous_version = waiting_version_;
-     if (previous_version.get())
-       previous_version->RemovePotentialControllee(this);
-     if (waiting_version)
-       waiting_version->AddPotentialControllee(this);
-     waiting_version_ = waiting_version;
-   }
-
-   if (active_version != active_version_.get()) {
-     scoped_refptr<ServiceWorkerVersion> previous_version = active_version_;
-     if (previous_version.get())
-       previous_version->RemovePotentialControllee(this);
-     if (active_version)
-       active_version->AddPotentialControllee(this);
-     active_version_ = active_version;
-   }
-}
-
 void ServiceWorkerProviderHost::SetControllerVersionAttribute(
     ServiceWorkerVersion* version) {
   if (version == controlling_version_.get())
@@ -144,20 +112,27 @@ bool ServiceWorkerProviderHost::SetHostedVersionId(int64 version_id) {
 void ServiceWorkerProviderHost::AssociateRegistration(
     ServiceWorkerRegistration* registration) {
   DCHECK(CanAssociateRegistration(registration));
+  if (associated_registration_.get())
+    DecreaseProcessReference(associated_registration_->pattern());
+  IncreaseProcessReference(registration->pattern());
+
   associated_registration_ = registration;
   registration->AddListener(this);
-  UpdatePotentialControllees(registration->installing_version(),
-                             registration->waiting_version(),
-                             registration->active_version());
+  installing_version_ = registration->installing_version();
+  waiting_version_ = registration->waiting_version();
+  active_version_ = registration->active_version();
   SetControllerVersionAttribute(registration->active_version());
 }
 
 void ServiceWorkerProviderHost::UnassociateRegistration() {
   if (!associated_registration_.get())
     return;
+  DecreaseProcessReference(associated_registration_->pattern());
   associated_registration_->RemoveListener(this);
   associated_registration_ = NULL;
-  UpdatePotentialControllees(NULL, NULL, NULL);
+  installing_version_ = NULL;
+  waiting_version_ = NULL;
+  active_version_ = NULL;
   SetControllerVersionAttribute(NULL);
 }
 
@@ -210,6 +185,12 @@ void ServiceWorkerProviderHost::PostMessage(
           new_routing_ids));
 }
 
+void ServiceWorkerProviderHost::AddScopedProcessReferenceToPattern(
+    const GURL& pattern) {
+  associated_patterns_.push_back(pattern);
+  IncreaseProcessReference(pattern);
+}
+
 ServiceWorkerObjectInfo ServiceWorkerProviderHost::CreateHandleAndPass(
     ServiceWorkerVersion* version) {
   ServiceWorkerObjectInfo info;
@@ -226,6 +207,22 @@ ServiceWorkerObjectInfo ServiceWorkerProviderHost::CreateHandleAndPass(
   return info;
 }
 
+void ServiceWorkerProviderHost::IncreaseProcessReference(
+    const GURL& pattern) {
+  if (context_ && context_->process_manager()) {
+    context_->process_manager()->AddProcessReferenceToPattern(
+        pattern, process_id_);
+  }
+}
+
+void ServiceWorkerProviderHost::DecreaseProcessReference(
+    const GURL& pattern) {
+  if (context_ && context_->process_manager()) {
+    context_->process_manager()->RemoveProcessReferenceFromPattern(
+        pattern, process_id_);
+  }
+}
+
 bool ServiceWorkerProviderHost::IsContextAlive() {
   return context_ != NULL;
 }
diff --git a/content/browser/service_worker/service_worker_provider_host.h b/content/browser/service_worker/service_worker_provider_host.h
index 6a6134a..a005e0a 100644
--- a/content/browser/service_worker/service_worker_provider_host.h
+++ b/content/browser/service_worker/service_worker_provider_host.h
@@ -107,6 +107,10 @@ class CONTENT_EXPORT ServiceWorkerProviderHost
   void PostMessage(const base::string16& message,
                    const std::vector<int>& sent_message_port_ids);
 
+  // Adds reference of this host's process to the |pattern|, the reference will
+  // be removed in destructor.
+  void AddScopedProcessReferenceToPattern(const GURL& pattern);
+
  private:
   friend class ServiceWorkerProviderHostTest;
   FRIEND_TEST_ALL_PREFIXES(ServiceWorkerContextRequestHandlerTest,
@@ -122,13 +126,6 @@ class CONTENT_EXPORT ServiceWorkerProviderHost
   virtual void OnRegistrationFailed(
       ServiceWorkerRegistration* registration) OVERRIDE;
 
-  // Adds this provider host to the potential controllee list of the given
-  // versions and removes it from the previous versions.
-  void UpdatePotentialControllees(
-      ServiceWorkerVersion* installing_version,
-      ServiceWorkerVersion* waiting_version,
-      ServiceWorkerVersion* active_version);
-
   // Sets the controller version field to |version| or if |version| is NULL,
   // clears the field.
   void SetControllerVersionAttribute(ServiceWorkerVersion* version);
@@ -138,10 +135,15 @@ class CONTENT_EXPORT ServiceWorkerProviderHost
   // provider is responsible for releasing the handle.
   ServiceWorkerObjectInfo CreateHandleAndPass(ServiceWorkerVersion* version);
 
+  // Increase/decrease this host's process reference for |pattern|.
+  void IncreaseProcessReference(const GURL& pattern);
+  void DecreaseProcessReference(const GURL& pattern);
+
   const int process_id_;
   const int provider_id_;
   GURL document_url_;
 
+  std::vector<GURL> associated_patterns_;
   scoped_refptr<ServiceWorkerRegistration> associated_registration_;
 
   scoped_refptr<ServiceWorkerVersion> controlling_version_;
diff --git a/content/browser/service_worker/service_worker_provider_host_unittest.cc b/content/browser/service_worker/service_worker_provider_host_unittest.cc
index c4b2cd8..181ecf7 100644
--- a/content/browser/service_worker/service_worker_provider_host_unittest.cc
+++ b/content/browser/service_worker/service_worker_provider_host_unittest.cc
@@ -5,6 +5,7 @@
 #include "base/basictypes.h"
 #include "base/memory/weak_ptr.h"
 #include "base/thread_task_runner_handle.h"
+#include "content/browser/service_worker/embedded_worker_test_helper.h"
 #include "content/browser/service_worker/service_worker_context_core.h"
 #include "content/browser/service_worker/service_worker_provider_host.h"
 #include "content/browser/service_worker/service_worker_register_job.h"
@@ -24,19 +25,12 @@ class ServiceWorkerProviderHostTest : public testing::Test {
   virtual ~ServiceWorkerProviderHostTest() {}
 
   virtual void SetUp() OVERRIDE {
-    context_.reset(
-        new ServiceWorkerContextCore(base::FilePath(),
-                                     base::ThreadTaskRunnerHandle::Get(),
-                                     base::ThreadTaskRunnerHandle::Get(),
-                                     base::ThreadTaskRunnerHandle::Get(),
-                                     NULL,
-                                     NULL,
-                                     NULL));
-
-    scope_ = GURL("http://www.example.com/");
+    helper_.reset(new EmbeddedWorkerTestHelper(kRenderProcessId));
+    context_ = helper_->context();
+    pattern_ = GURL("http://www.example.com/");
     script_url_ = GURL("http://www.example.com/service_worker.js");
     registration_ = new ServiceWorkerRegistration(
-        scope_, 1L, context_->AsWeakPtr());
+        pattern_, 1L, context_->AsWeakPtr());
     version_ = new ServiceWorkerVersion(
         registration_.get(), script_url_, 1L, context_->AsWeakPtr());
 
@@ -56,7 +50,11 @@ class ServiceWorkerProviderHostTest : public testing::Test {
   virtual void TearDown() OVERRIDE {
     version_ = 0;
     registration_ = 0;
-    context_.reset();
+    helper_.reset();
+  }
+
+  bool HasProcessToRun() const {
+    return context_->process_manager()->PatternHasProcessToRun(pattern_);
   }
 
   void VerifyVersionAttributes(
@@ -71,12 +69,13 @@ class ServiceWorkerProviderHostTest : public testing::Test {
   }
 
   content::TestBrowserThreadBundle thread_bundle_;
-  scoped_ptr<ServiceWorkerContextCore> context_;
+  scoped_ptr<EmbeddedWorkerTestHelper> helper_;
+  ServiceWorkerContextCore* context_;
   scoped_refptr<ServiceWorkerRegistration> registration_;
   scoped_refptr<ServiceWorkerVersion> version_;
   base::WeakPtr<ServiceWorkerProviderHost> provider_host1_;
   base::WeakPtr<ServiceWorkerProviderHost> provider_host2_;
-  GURL scope_;
+  GURL pattern_;
   GURL script_url_;
 
  private:
@@ -85,80 +84,80 @@ class ServiceWorkerProviderHostTest : public testing::Test {
 
 TEST_F(ServiceWorkerProviderHostTest, SetActiveVersion_ProcessStatus) {
   provider_host1_->AssociateRegistration(registration_.get());
-  ASSERT_FALSE(version_->HasProcessToRun());
+  ASSERT_TRUE(HasProcessToRun());
 
   // Associating version_ to a provider_host's active version will internally
   // add the provider_host's process ref to the version.
   registration_->SetActiveVersion(version_.get());
-  ASSERT_TRUE(version_->HasProcessToRun());
+  ASSERT_TRUE(HasProcessToRun());
 
   // Re-associating the same version and provider_host should just work too.
   registration_->SetActiveVersion(version_.get());
-  ASSERT_TRUE(version_->HasProcessToRun());
+  ASSERT_TRUE(HasProcessToRun());
 
   // Resetting the provider_host's active version should remove process refs
   // from the version.
   provider_host1_->UnassociateRegistration();
-  ASSERT_FALSE(version_->HasProcessToRun());
+  ASSERT_FALSE(HasProcessToRun());
 }
 
 TEST_F(ServiceWorkerProviderHostTest,
        SetActiveVersion_MultipleHostsForSameProcess) {
   provider_host1_->AssociateRegistration(registration_.get());
   provider_host2_->AssociateRegistration(registration_.get());
-  ASSERT_FALSE(version_->HasProcessToRun());
+  ASSERT_TRUE(HasProcessToRun());
 
   // Associating version_ to two providers as active version.
   registration_->SetActiveVersion(version_.get());
-  ASSERT_TRUE(version_->HasProcessToRun());
+  ASSERT_TRUE(HasProcessToRun());
 
   // Disassociating one provider_host shouldn't remove all process refs
   // from the version yet.
   provider_host1_->UnassociateRegistration();
-  ASSERT_TRUE(version_->HasProcessToRun());
+  ASSERT_TRUE(HasProcessToRun());
 
   // Disassociating the other provider_host will remove all process refs.
   provider_host2_->UnassociateRegistration();
-  ASSERT_FALSE(version_->HasProcessToRun());
+  ASSERT_FALSE(HasProcessToRun());
 }
 
 TEST_F(ServiceWorkerProviderHostTest, SetWaitingVersion_ProcessStatus) {
   provider_host1_->AssociateRegistration(registration_.get());
-  ASSERT_FALSE(version_->HasProcessToRun());
+  ASSERT_TRUE(HasProcessToRun());
 
   // Associating version_ to a provider_host's waiting version will internally
   // add the provider_host's process ref to the version.
   registration_->SetWaitingVersion(version_.get());
-  ASSERT_TRUE(version_->HasProcessToRun());
+  ASSERT_TRUE(HasProcessToRun());
 
   // Re-associating the same version and provider_host should just work too.
   registration_->SetWaitingVersion(version_.get());
-  ASSERT_TRUE(version_->HasProcessToRun());
+  ASSERT_TRUE(HasProcessToRun());
 
   // Resetting the provider_host's waiting version should remove process refs
   // from the version.
   provider_host1_->UnassociateRegistration();
-  ASSERT_FALSE(version_->HasProcessToRun());
+  ASSERT_FALSE(HasProcessToRun());
 }
 
 TEST_F(ServiceWorkerProviderHostTest,
        SetWaitingVersion_MultipleHostsForSameProcess) {
   provider_host1_->AssociateRegistration(registration_.get());
   provider_host2_->AssociateRegistration(registration_.get());
-  ASSERT_FALSE(version_->HasProcessToRun());
+  ASSERT_TRUE(HasProcessToRun());
 
   // Associating version_ to two providers as waiting version.
   registration_->SetWaitingVersion(version_.get());
-  ASSERT_TRUE(version_->HasProcessToRun());
+  ASSERT_TRUE(HasProcessToRun());
 
   // Disassociating one provider_host shouldn't remove all process refs
   // from the version yet.
   provider_host1_->UnassociateRegistration();
-  ASSERT_TRUE(version_->HasProcessToRun());
+  ASSERT_TRUE(HasProcessToRun());
 
   // Disassociating the other provider_host will remove all process refs.
   provider_host2_->UnassociateRegistration();
-  ASSERT_FALSE(version_->HasProcessToRun());
+  ASSERT_FALSE(HasProcessToRun());
 }
 
 TEST_F(ServiceWorkerProviderHostTest,
diff --git a/content/browser/service_worker/service_worker_register_job.cc b/content/browser/service_worker/service_worker_register_job.cc
index 5c96d87..c19da94 100644
--- a/content/browser/service_worker/service_worker_register_job.cc
+++ b/content/browser/service_worker/service_worker_register_job.cc
@@ -58,12 +58,13 @@ ServiceWorkerRegisterJob::~ServiceWorkerRegisterJob() {
       << "Jobs should only be interrupted during shutdown.";
 }
 
-void ServiceWorkerRegisterJob::AddCallback(const RegistrationCallback& callback,
-                                           int process_id) {
+void ServiceWorkerRegisterJob::AddCallback(
+    const RegistrationCallback& callback,
+    ServiceWorkerProviderHost* provider_host) {
   if (!is_promise_resolved_) {
     callbacks_.push_back(callback);
-    if (process_id != -1 && (phase_ < UPDATE || !new_version()))
-      pending_process_ids_.push_back(process_id);
+    if (provider_host)
+      provider_host->AddScopedProcessReferenceToPattern(pattern_);
     return;
   }
   RunSoon(base::Bind(
@@ -323,8 +324,7 @@ void ServiceWorkerRegisterJob::UpdateAndContinue() {
   bool pause_after_download = job_type_ == UPDATE_JOB;
   if (pause_after_download)
     new_version()->embedded_worker()->AddListener(this);
-  new_version()->StartWorkerWithCandidateProcesses(
-      pending_process_ids_,
+  new_version()->StartWorker(
       pause_after_download,
       base::Bind(&ServiceWorkerRegisterJob::OnStartWorkerFinished,
                  weak_factory_.GetWeakPtr()));
diff --git a/content/browser/service_worker/service_worker_register_job.h b/content/browser/service_worker/service_worker_register_job.h
index 7153fa1..c281ed2 100644
--- a/content/browser/service_worker/service_worker_register_job.h
+++ b/content/browser/service_worker/service_worker_register_job.h
@@ -55,11 +55,11 @@ class ServiceWorkerRegisterJob : public ServiceWorkerRegisterJobBase,
   virtual ~ServiceWorkerRegisterJob();
 
   // Registers a callback to be called when the promise would resolve (whether
-  // successfully or not). Multiple callbacks may be registered. If |process_id|
-  // is not -1, it's added to the existing clients when deciding in which
-  // process to create the Service Worker instance.  If there are no existing
-  // clients, a new RenderProcessHost will be created.
-  void AddCallback(const RegistrationCallback& callback, int process_id);
+  // successfully or not). Multiple callbacks may be registered.
+  // If |provider_host| is not NULL, its process will be regarded as a candidate
+  // process to run the worker.
+  void AddCallback(const RegistrationCallback& callback,
+                   ServiceWorkerProviderHost* provider_host);
 
   // ServiceWorkerRegisterJobBase implementation:
   virtual void Start() OVERRIDE;
@@ -158,7 +158,6 @@ class ServiceWorkerRegisterJob : public ServiceWorkerRegisterJobBase,
   const GURL pattern_;
   const GURL script_url_;
   std::vector<RegistrationCallback> callbacks_;
-  std::vector<int> pending_process_ids_;
   Phase phase_;
   Internal internal_;
   bool is_promise_resolved_;
diff --git a/content/browser/service_worker/service_worker_version.cc b/content/browser/service_worker/service_worker_version.cc
index 82bb676..88d8e48 100644
--- a/content/browser/service_worker/service_worker_version.cc
+++ b/content/browser/service_worker/service_worker_version.cc
@@ -160,11 +160,10 @@ ServiceWorkerVersionInfo ServiceWorkerVersion::GetInfo() {
 }
 
 void ServiceWorkerVersion::StartWorker(const StatusCallback& callback) {
-  StartWorkerWithCandidateProcesses(std::vector<int>(), false, callback);
+  StartWorker(false, callback);
 }
 
-void ServiceWorkerVersion::StartWorkerWithCandidateProcesses(
-    const std::vector<int>& possible_process_ids,
+void ServiceWorkerVersion::StartWorker(
     bool pause_after_download,
     const StatusCallback& callback) {
   switch (running_status()) {
@@ -183,7 +182,6 @@ void ServiceWorkerVersion::StartWorkerWithCandidateProcesses(
             scope_,
             script_url_,
             pause_after_download,
-            possible_process_ids,
             base::Bind(&ServiceWorkerVersion::RunStartWorkerCallbacksOnError,
                        weak_factory_.GetWeakPtr()));
       }
@@ -376,24 +374,11 @@ void ServiceWorkerVersion::DispatchPushEvent(const StatusCallback& callback,
   }
 }
 
-void ServiceWorkerVersion::AddProcessToWorker(int process_id) {
-  embedded_worker_->AddProcessReference(process_id);
-}
-
-void ServiceWorkerVersion::RemoveProcessFromWorker(int process_id) {
-  embedded_worker_->ReleaseProcessReference(process_id);
-}
-
-bool ServiceWorkerVersion::HasProcessToRun() const {
-  return embedded_worker_->HasProcessToRun();
-}
-
 void ServiceWorkerVersion::AddControllee(
     ServiceWorkerProviderHost* provider_host) {
   DCHECK(!ContainsKey(controllee_map_, provider_host));
   int controllee_id = controllee_by_id_.Add(provider_host);
   controllee_map_[provider_host] = controllee_id;
-  AddProcessToWorker(provider_host->process_id());
   if (stop_worker_timer_.IsRunning())
     stop_worker_timer_.Stop();
 }
@@ -404,7 +389,6 @@ void ServiceWorkerVersion::RemoveControllee(
   DCHECK(found != controllee_map_.end());
   controllee_by_id_.Remove(found->second);
   controllee_map_.erase(found);
-  RemoveProcessFromWorker(provider_host->process_id());
   if (HasControllee())
     return;
   FOR_EACH_OBSERVER(Listener, listeners_, OnNoControllees(this));
@@ -415,16 +399,6 @@ void ServiceWorkerVersion::RemoveControllee(
   ScheduleStopWorker();
 }
 
-void ServiceWorkerVersion::AddPotentialControllee(
-    ServiceWorkerProviderHost* provider_host) {
-  AddProcessToWorker(provider_host->process_id());
-}
-
-void ServiceWorkerVersion::RemovePotentialControllee(
-    ServiceWorkerProviderHost* provider_host) {
-  RemoveProcessFromWorker(provider_host->process_id());
-}
-
 void ServiceWorkerVersion::AddListener(Listener* listener) {
   listeners_.AddObserver(listener);
 }
diff --git a/content/browser/service_worker/service_worker_version.h b/content/browser/service_worker/service_worker_version.h
index ee1194e..9d0b342 100644
--- a/content/browser/service_worker/service_worker_version.h
+++ b/content/browser/service_worker/service_worker_version.h
@@ -123,13 +123,11 @@ class CONTENT_EXPORT ServiceWorkerVersion
   void StartWorker(const StatusCallback& callback);
 
   // Starts an embedded worker for this version.
-  // |potential_process_ids| is a list of processes in which to start the
-  // worker.
+  // |pause_after_download| notifies worker to pause after download finished
+  // which could be resumed by EmbeddedWorkerInstance::ResumeAfterDownload.
   // This returns OK (success) if the worker is already running.
-  void StartWorkerWithCandidateProcesses(
-      const std::vector<int>& potential_process_ids,
-      bool pause_after_download,
-      const StatusCallback& callback);
+  void StartWorker(bool pause_after_download,
+                   const StatusCallback& callback);
 
   // Stops an embedded worker for this version.
   // This returns OK (success) if the worker is already stopped.
@@ -199,22 +197,11 @@ class CONTENT_EXPORT ServiceWorkerVersion
   void DispatchPushEvent(const StatusCallback& callback,
                          const std::string& data);
 
-  // These are expected to be called when a renderer process host for the
-  // same-origin as for this ServiceWorkerVersion is created.  The added
-  // processes are used to run an in-renderer embedded worker.
-  void AddProcessToWorker(int process_id);
-  void RemoveProcessFromWorker(int process_id);
-
-  // Returns true if this has at least one process to run.
-  bool HasProcessToRun() const;
-
   // Adds and removes |provider_host| as a controllee of this ServiceWorker.
   // A potential controllee is a host having the version as its .installing
   // or .waiting version.
   void AddControllee(ServiceWorkerProviderHost* provider_host);
   void RemoveControllee(ServiceWorkerProviderHost* provider_host);
-  void AddPotentialControllee(ServiceWorkerProviderHost* provider_host);
-  void RemovePotentialControllee(ServiceWorkerProviderHost* provider_host);
 
   // Returns if it has controllee.
   bool HasControllee() const { return !controllee_map_.empty(); }
diff --git a/content/browser/service_worker/service_worker_version_unittest.cc b/content/browser/service_worker/service_worker_version_unittest.cc
index 11e5440..3fcc13f 100644
--- a/content/browser/service_worker/service_worker_version_unittest.cc
+++ b/content/browser/service_worker/service_worker_version_unittest.cc
@@ -119,8 +119,9 @@ class ServiceWorkerVersionTest : public testing::Test {
   virtual void SetUp() OVERRIDE {
     helper_.reset(new MessageReceiver());
 
+    pattern_ = GURL("http://www.example.com/");
     registration_ = new ServiceWorkerRegistration(
-        GURL("http://www.example.com/"),
+        pattern_,
         1L,
         helper_->context()->AsWeakPtr());
     version_ = new ServiceWorkerVersion(
@@ -129,10 +130,10 @@ class ServiceWorkerVersionTest : public testing::Test {
         1L,
         helper_->context()->AsWeakPtr());
 
-    // Simulate adding one process to the worker.
-    int embedded_worker_id = version_->embedded_worker()->embedded_worker_id();
-    helper_->SimulateAddProcessToWorker(embedded_worker_id, kRenderProcessId);
-    ASSERT_TRUE(version_->HasProcessToRun());
+    // Simulate adding one process to the pattern.
+    helper_->SimulateAddProcessToPattern(pattern_, kRenderProcessId);
+    ASSERT_TRUE(helper_->context()->process_manager()
+        ->PatternHasProcessToRun(pattern_));
   }
 
   virtual void TearDown() OVERRIDE {
@@ -145,6 +146,7 @@ class ServiceWorkerVersionTest : public testing::Test {
   scoped_ptr<MessageReceiver> helper_;
   scoped_refptr<ServiceWorkerRegistration> registration_;
   scoped_refptr<ServiceWorkerVersion> version_;
+  GURL pattern_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ServiceWorkerVersionTest);
@@ -327,28 +329,6 @@ TEST_F(ServiceWorkerVersionTest, RepeatedlyObserveStatusChanges) {
   ASSERT_EQ(ServiceWorkerVersion::REDUNDANT, statuses[4]);
 }
 
-TEST_F(ServiceWorkerVersionTest, AddAndRemoveProcesses) {
-  // Preparation (to reset the process count to 0).
-  ASSERT_TRUE(version_->HasProcessToRun());
-  version_->RemoveProcessFromWorker(kRenderProcessId);
-  ASSERT_FALSE(version_->HasProcessToRun());
-
-  // Add another process to the worker twice, and then remove process once.
-  const int another_process_id = kRenderProcessId + 1;
-  version_->AddProcessToWorker(another_process_id);
-  version_->AddProcessToWorker(another_process_id);
-  version_->RemoveProcessFromWorker(another_process_id);
-
-  // We're ref-counting the process internally, so adding the same process
-  // multiple times should be handled correctly.
-  ASSERT_TRUE(version_->HasProcessToRun());
-
-  // Removing the process again (so that # of AddProcess == # of RemoveProcess
-  // for the process) should remove all process references.
-  version_->RemoveProcessFromWorker(another_process_id);
-  ASSERT_FALSE(version_->HasProcessToRun());
-}
-
 TEST_F(ServiceWorkerVersionTest, ScheduleStopWorker) {
   // Verify the timer is not running when version initializes its status.
   version_->SetStatus(ServiceWorkerVersion::ACTIVATED);
diff --git a/content/content_tests.gypi b/content/content_tests.gypi
index 835f4fe..b13ee86 100644
--- a/content/content_tests.gypi
+++ b/content/content_tests.gypi
@@ -597,6 +597,7 @@
         'browser/service_worker/service_worker_dispatcher_host_unittest.cc',
         'browser/service_worker/service_worker_handle_unittest.cc',
         'browser/service_worker/service_worker_job_unittest.cc',
+        'browser/service_worker/service_worker_process_manager_unittest.cc',
         'browser/service_worker/service_worker_provider_host_unittest.cc',
         'browser/service_worker/service_worker_registration_unittest.cc',
         'browser/service_worker/service_worker_request_handler_unittest.cc',