Convert the PluginService interface to be an async wrapper around PluginList.

chrome/browser/metrics/metrics_service.h

 // Copyright (c) 2011 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.
 
 // This file defines a service that collects information about the user
 // experience in order to help improve future versions of the app.
 
 #ifndef CHROME_BROWSER_METRICS_METRICS_SERVICE_H_
 #define CHROME_BROWSER_METRICS_METRICS_SERVICE_H_
 #pragma once
@@ skipping 19 matching lines @@
 class BookmarkNode;
 class HistogramSynchronizer;
 class MetricsLogBase;
 class MetricsReportingScheduler;
 class PrefService;
 class TemplateURLService;
 
 namespace base {
 class DictionaryValue;
 class ListValue;
+class MessageLoopProxy;
 }
 
 namespace webkit {
 struct WebPluginInfo;
 }
 
 class MetricsService : public NotificationObserver,
                        public URLFetcher::Delegate,
                        public MetricsServiceBase {
  public:
@@ skipping 97 matching lines @@
   enum State {
     INITIALIZED,            // Constructor was called.
     INIT_TASK_SCHEDULED,    // Waiting for deferred init tasks to complete.
     INIT_TASK_DONE,         // Waiting for timer to send initial log.
     INITIAL_LOG_READY,      // Initial log generated, and waiting for reply.
     SEND_OLD_INITIAL_LOGS,  // Sending unsent logs from previous session.
     SENDING_OLD_LOGS,       // Sending unsent logs from previous session.
     SENDING_CURRENT_LOGS,   // Sending standard current logs as they acrue.
   };
 
+  // When in the INIT_TASK_SCHEDULED state, multiple tasks are performed. In the

[jam, 2011/09/21 00:04:51]

are all these changes really necessary? can't we keep metrics service the same,
and just do the plugins/hwclass tasks serially to minimize the changes from this
cl?

[Robert Sesek, 2011/09/21 01:13:44]

Ok. Made the init tasks serial.

+  // completion callback, when all init tasks are done, the service moves to
+  // INIT_TASK_DONE.
+  enum InitSubtaskState {
+    INIT_SUBTASK_UNSTARTED = 0,       // Init subtasks have not been started.
+    INIT_SUBTASK_PLUGINS   = 1 << 0,  // Finished loading the plugin list.
+    INIT_SUBTASK_HWCLASS   = 1 << 1,  // Finished loading the hardware class.
+    INIT_SUBTASK_ALL       = INIT_SUBTASK_PLUGINS | INIT_SUBTASK_HWCLASS,
+  };
+
   enum ShutdownCleanliness {
     CLEANLY_SHUTDOWN = 0xdeadbeef,
     NEED_TO_SHUTDOWN = ~CLEANLY_SHUTDOWN
   };
 
-  class InitTask;
-  class InitTaskComplete;
+  // Method that is run as a delayed task after the MetricsService is
+  // constructed to perform initialization tasks.
+  void RunInitTasks();
 
-  // Callback to let us know that the init task is done.
-  void OnInitTaskComplete(
-      const std::string& hardware_class,
-      const std::vector<webkit::WebPluginInfo>& plugins);
+  // Called on the FILE thread to load hardware class information.
+  void InitTaskGetHardwareClass(base::MessageLoopProxy* target_loop);
+
+  // Callbacks to let us know that the init task is done.
+  void OnInitTaskGotHardwareClass(const std::string& hardware_class);
+  void OnInitTaskGotPluginInfo(
+      std::vector<webkit::WebPluginInfo> plugins);
+
+  // Moves the |state_| to INIT_TASK_DONE if all the init subtasks have
+  // completed.
+  void OnInitTaskMaybeDone();
 
   // When we start a new version of Chromium (different from our last run), we
   // need to discard the old crash stats so that we don't attribute crashes etc.
   // in the old version to the current version (via current logs).
   // Without this, a common reason to finally start a new version is to crash
   // the old version (after an autoupdate has arrived), and so we'd bias
   // initial results towards showing crashes :-(.
   static void DiscardOldStabilityStats(PrefService* local_state);
 
   // Sets and gets whether metrics recording is active.
@@ skipping 172 matching lines @@
   // Indicate whether recording and reporting are currently happening.
   // These should not be set directly, but by calling SetRecording and
   // SetReporting.
   bool recording_active_;
   bool reporting_active_;
 
   // The progession of states made by the browser are recorded in the following
   // state.
   State state_;
 
+  // The state of the init subtask.
+  uint32 init_state_;
+
   // Chrome OS hardware class (e.g., hardware qualification ID). This
   // class identifies the configured system components such as CPU,
   // WiFi adapter, etc.  For non Chrome OS hosts, this will be an
   // empty string.
   std::string hardware_class_;
 
   // The list of plugins which was retrieved on the file thread.
   std::vector<webkit::WebPluginInfo> plugins_;
 
   // The outstanding transmission appears as a URL Fetch operation.
@@ skipping 86 matching lines @@
  private:
   friend class InstantFieldTrial;
 
   // Returns true if prefs::kMetricsReportingEnabled is set.
   static bool IsMetricsReportingEnabled();
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(MetricsServiceHelper);
 };
 
 #endif  // CHROME_BROWSER_METRICS_METRICS_SERVICE_H_