Add Desktop iOS promotion logging to chrome ios app.

ios/chrome/app/main_controller.mm

 // Copyright 2012 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.
 
 #import "ios/chrome/app/main_controller.h"
 
 #include <memory>
 #include <string>
 
 #import <CoreSpotlight/CoreSpotlight.h>
@@ skipping 53 matching lines @@
 #include "ios/chrome/browser/browsing_data/ios_chrome_browsing_data_remover.h"
 #include "ios/chrome/browser/callback_counter.h"
 #include "ios/chrome/browser/chrome_paths.h"
 #include "ios/chrome/browser/chrome_url_constants.h"
 #import "ios/chrome/browser/chrome_url_util.h"
 #include "ios/chrome/browser/content_settings/host_content_settings_map_factory.h"
 #include "ios/chrome/browser/crash_loop_detection_util.h"
 #include "ios/chrome/browser/crash_report/breakpad_helper.h"
 #import "ios/chrome/browser/crash_report/crash_report_background_uploader.h"
 #import "ios/chrome/browser/crash_report/crash_restore_helper.h"
+#include "ios/chrome/browser/desktop_promotion/desktop_promotion_sync_observer.h"
 #include "ios/chrome/browser/experimental_flags.h"
 #include "ios/chrome/browser/file_metadata_util.h"
 #import "ios/chrome/browser/first_run/first_run.h"
 #include "ios/chrome/browser/geolocation/omnibox_geolocation_controller.h"
 #include "ios/chrome/browser/ios_chrome_io_thread.h"
 #import "ios/chrome/browser/memory/memory_debugger_manager.h"
 #include "ios/chrome/browser/metrics/first_user_action_recorder.h"
 #import "ios/chrome/browser/metrics/previous_session_info.h"
 #import "ios/chrome/browser/net/cookie_util.h"
 #include "ios/chrome/browser/net/crl_set_fetcher.h"
@@ skipping 244 matching lines @@
   // been processed in the last 200ms in order to only allow processing one at
   // a time.
   // TODO(crbug.com/560296):  Provide a general solution for handling mutually
   // exclusive chrome commands sent at nearly the same time.
   BOOL _isProcessingTabSwitcherCommand;
   BOOL _isProcessingVoiceSearchCommand;
 
   // Bridge to listen to pref changes.
   std::unique_ptr<PrefObserverBridge> _localStatePrefObserverBridge;
 
+  // Sync service observer for the desktop ios promotion logging.
+  std::unique_ptr<DesktopPromotionSyncObserver> _desktopPromotionSyncObserver;

[rohitrao (ping after 24h), 2017/01/23 20:31:39]

Can this be a BrowserStateKeyedService instead of needing to live in
MainController?  It looks like this object's lifetime is scoped to a
BrowserState already.  The tricky part will be figuring out where in the code to
create it, we might need Sylvain's help with that.

+
   // Registrar for pref changes notifications to the local state.
   PrefChangeRegistrar _localStatePrefChangeRegistrar;
 
   // Clears browsing data from ChromeBrowserStates.
   base::scoped_nsobject<BrowsingDataRemovalController>
       _browsingDataRemovalController;
 
   // The class in charge of showing/hiding the memory debugger when the
   // appropriate pref changes.
   base::scoped_nsobject<MemoryDebuggerManager> _memoryDebuggerManager;
@@ skipping 704 matching lines @@
                         new PrefObserverBridge(self));
                     _localStatePrefChangeRegistrar.Init(
                         GetApplicationContext()->GetLocalState());
                     _localStatePrefObserverBridge->ObserveChangesForPreference(
                         metrics::prefs::kMetricsReportingEnabled,
                         &_localStatePrefChangeRegistrar);
                     _localStatePrefObserverBridge->ObserveChangesForPreference(
                         prefs::kMetricsReportingWifiOnly,
                         &_localStatePrefChangeRegistrar);
 
+                    // Track Sync state changes.
+                    _desktopPromotionSyncObserver.reset(
+                        new DesktopPromotionSyncObserver(
+                            [self currentBrowserState]));

[rohitrao (ping after 24h), 2017/01/23 20:31:39]

Are you intentionally calling |currentBrowserState| here?  What happens if the
app starts up in incognito mode, or if the user switches to incognito before
this block runs?  Which BrowserState do want to use in those cases?

[mrefaat, 2017/01/24 19:57:19]

changed to use _mainBrowserState - we don't care about incognito

+
                     // Calls the onPreferenceChanged function in case there was
                     // a
                     // change to the observed preferences before the observer
                     // bridge was set up.
                     [self onPreferenceChanged:metrics::prefs::
                                                   kMetricsReportingEnabled];
                     [self onPreferenceChanged:prefs::kMetricsReportingWifiOnly];
                   }];
 }
 
@@ skipping 1620 matching lines @@
   };
 
   callbackCounter->IncrementCount();
   [self removeBrowsingDataFromBrowserState:_mainBrowserState
                                       mask:removeAllMask
                                 timePeriod:browsing_data::ALL_TIME
                          completionHandler:decrementCallbackCounterCount];
 }
 
 @end