Added asynchronous notification of readiness to the StatisticsProvider, and

chrome/browser/metrics/metrics_service.h

Index: chrome/browser/metrics/metrics_service.h
diff --git a/chrome/browser/metrics/metrics_service.h b/chrome/browser/metrics/metrics_service.h
index 82c89cf8047bbe49cc34c2ad2c061e3de9feec4a..e64a565d7937f0e57cefd6775e71fd0a7d172f91 100644
--- a/chrome/browser/metrics/metrics_service.h
+++ b/chrome/browser/metrics/metrics_service.h
@@ -14,6 +14,7 @@
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/cancelable_callback.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ -28,6 +29,7 @@
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/external_metrics.h"
+#include "chrome/browser/chromeos/system/statistics_provider.h"
 #endif
 
 class BookmarkModel;
@@ -66,6 +68,9 @@ class MetricsService
     : public chrome_browser_metrics::TrackingSynchronizerObserver,
       public content::NotificationObserver,
       public content::URLFetcherDelegate,
+#if defined(OS_CHROMEOS)
+      public chromeos::system::StatisticsProvider::Observer,
+#endif
       public MetricsServiceBase {
  public:
   MetricsService();
@@ -158,14 +163,22 @@ class MetricsService
     NEED_TO_SHUTDOWN = ~CLEANLY_SHUTDOWN
   };
 
-  // First part of the init task. Called on the FILE thread to load hardware
-  // class information.
-  static void InitTaskGetHardwareClass(base::WeakPtr<MetricsService> self,
-                                       base::MessageLoopProxy* target_loop);
+  // First init task, that starts retrieving the hardware class. It proceeds
+  // to InitTaskGetPluginInfo after reading the hardware_class, or after
+  // timing out waiting for it.
+  void InitTaskGetHardwareClass();
 
-  // Callback from InitTaskGetHardwareClass() that continues the init task by
-  // loading plugin information.
-  void OnInitTaskGotHardwareClass(const std::string& hardware_class);
+#if defined(OS_CHROMEOS)
+  // chromeos::system::StatisticsProvider::Observer implementation:
+  virtual void OnMachineStatisticsReady() OVERRIDE;
+
+  // Handles a timeout while waiting for the StatisticsProvider to become ready
+  // during initialization.
+  void OnStatisticsProviderTimeout();
+#endif
+
+  // Second init task, that starts retrieving plugin info.
+  void InitTaskGetPluginInfo();
 
   // Callback from PluginService::GetPlugins() that continues the init task by
   // launching a task to gather Google Update statistics.
@@ -440,6 +453,11 @@ class MetricsService
 #if defined(OS_CHROMEOS)
   // The external metric service is used to log ChromeOS UMA events.
   scoped_refptr<chromeos::ExternalMetrics> external_metrics_;
+
+  // Used to resume initialization of the MetricsService when the
+  // StatisticsProvider becomes ready, or after timing out while waiting for it.
+  base::CancelableClosure timeout_callback_;
+  base::CancelableClosure on_ready_callback_;

[Ilya Sherman, 2012/05/16 01:01:17]

nit: I'd recommend either prefixing both callbacks with "on_", or neither.

[Joao da Silva, 2012/05/16 12:53:34]

Renamed to on_timeout_callback_.

 #endif
 
   // Reduntant marker to check that we completed our shutdown, and set the