Allow setting DeviceInfoTracker for testing in SharingSyncPreference

Bug: 1037793
Change-Id: Iee42f82af527875c936310764f323942c8f97023
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2062983Reviewed-by: Richard Knoll <knollr@chromium.org>
Commit-Queue: Alex Chau <alexchau@chromium.org>
Cr-Commit-Position: refs/heads/master@{#742683}

chrome/browser/sharing/sharing_sync_preference.cc

@@ -411,6 +411,12 @@ void SharingSyncPreference::ClearLocalSharingInfo() {
   }
 }
 
+void SharingSyncPreference::SetDeviceInfoTrackerForTesting(
+    syncer::DeviceInfoTracker* tracker) {
+  DCHECK(tracker);
+  device_info_tracker_ = tracker;
+}
+
 // static
 base::Optional<syncer::DeviceInfo::SharingInfo>
 SharingSyncPreference::GetLocalSharingInfo(PrefService* prefs) {

chrome/browser/sharing/sharing_sync_preference.h

@@ -112,6 +112,9 @@ class SharingSyncPreference {
 
   void ClearLocalSharingInfo();
 
+  // Replaces DeviceInfoTracker for testing.
+  void SetDeviceInfoTrackerForTesting(syncer::DeviceInfoTracker* tracker);
+
  private:
   friend class SharingSyncPreferenceTest;