Reland: Add GCMChannelStatusSyncer to schedule requests and enable/disable GCM

components/gcm_driver/gcm_driver_desktop.cc

Index: components/gcm_driver/gcm_driver_desktop.cc
diff --git a/components/gcm_driver/gcm_driver_desktop.cc b/components/gcm_driver/gcm_driver_desktop.cc
index 8d35c2c03acf9c2ed8b0fd8cfd00cb4ea2dd5656..82ca4b34320e1c14ef5e4e61e76307da0c1537ca 100644
--- a/components/gcm_driver/gcm_driver_desktop.cc
+++ b/components/gcm_driver/gcm_driver_desktop.cc
@@ -14,6 +14,7 @@
 #include "base/sequenced_task_runner.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "components/gcm_driver/gcm_app_handler.h"
+#include "components/gcm_driver/gcm_channel_status_syncer.h"
 #include "components/gcm_driver/gcm_client_factory.h"
 #include "components/gcm_driver/gcm_delayed_task_controller.h"
 #include "components/gcm_driver/system_encryptor.h"
@@ -329,18 +330,23 @@ void GCMDriverDesktop::IOWorker::RemoveAccountMapping(
 GCMDriverDesktop::GCMDriverDesktop(
     scoped_ptr<GCMClientFactory> gcm_client_factory,
     const GCMClient::ChromeBuildInfo& chrome_build_info,
+    PrefService* prefs,
     const base::FilePath& store_path,
     const scoped_refptr<net::URLRequestContextGetter>& request_context,
     const scoped_refptr<base::SequencedTaskRunner>& ui_thread,
     const scoped_refptr<base::SequencedTaskRunner>& io_thread,
     const scoped_refptr<base::SequencedTaskRunner>& blocking_task_runner)
-    : signed_in_(false),
+    : gcm_channel_status_syncer_(
+          new GCMChannelStatusSyncer(this, prefs, request_context)),
+      signed_in_(false),
       gcm_started_(false),
       gcm_enabled_(true),
       connected_(false),
       ui_thread_(ui_thread),
       io_thread_(io_thread),
       weak_ptr_factory_(this) {
+  gcm_enabled_ = gcm_channel_status_syncer_->gcm_enabled();
+
   // Create and initialize the GCMClient. Note that this does not initiate the
   // GCM check-in.
   io_worker_.reset(new IOWorker(ui_thread, io_thread));
@@ -361,6 +367,12 @@ GCMDriverDesktop::~GCMDriverDesktop() {
 void GCMDriverDesktop::Shutdown() {
   DCHECK(ui_thread_->RunsTasksOnCurrentThread());
   GCMDriver::Shutdown();
+
+  // Dispose the syncer in order to release the reference to
+  // URLRequestContextGetter that needs to be done before IOThread gets
+  // deleted.
+  gcm_channel_status_syncer_.reset();
+
   io_thread_->DeleteSoon(FROM_HERE, io_worker_.release());
 }
 
@@ -442,6 +454,8 @@ void GCMDriverDesktop::Stop() {
   if (!gcm_started_)
     return;
 
+  gcm_channel_status_syncer_->Stop();
+
   RemoveCachedData();
 
   io_thread_->PostTask(
@@ -627,6 +641,11 @@ GCMClient::Result GCMDriverDesktop::EnsureStarted() {
   DCHECK(!delayed_task_controller_);
   delayed_task_controller_.reset(new GCMDelayedTaskController);
 
+  // Polling for channel status is only needed when GCM is supported for all
+  // users.
+  if (GCMDriver::IsAllowedForAllUsers())
+    gcm_channel_status_syncer_->EnsureStarted();
+
   // Note that we need to pass weak pointer again since the existing weak
   // pointer in IOWorker might have been invalidated when check-out occurs.
   io_thread_->PostTask(