MD Settings: Fix policy-related ProfileSyncService crashes.

chrome/browser/ui/webui/settings/people_handler.cc

Index: chrome/browser/ui/webui/settings/people_handler.cc
diff --git a/chrome/browser/ui/webui/settings/people_handler.cc b/chrome/browser/ui/webui/settings/people_handler.cc
index d31837e724734edb75fc6eb5fa96ba0c62f84fb4..2fcfd1e1dcfd3070ee6ecd731baeef814351ee44 100644
--- a/chrome/browser/ui/webui/settings/people_handler.cc
+++ b/chrome/browser/ui/webui/settings/people_handler.cc
@@ -775,7 +775,10 @@ void PeopleHandler::PushSyncPrefs() {
     return;
 
   ProfileSyncService* service = GetSyncService();
-  DCHECK(service);
+  // The sync service may be nullptr if it has been just disabled by policy.
+  if (!service)
+    return;
+
   if (!service->IsEngineInitialized()) {
     // Requesting the sync service to start may trigger another reentrant call
     // to PushSyncPrefs. Setting up the startup tracker beforehand correctly
@@ -903,8 +906,8 @@ void PeopleHandler::MarkFirstSetupComplete() {
   signin::SetUserSkippedPromo(profile_);
 
   ProfileSyncService* service = GetSyncService();
-  DCHECK(service);
-  if (service->IsFirstSetupComplete())
+  // The sync service may be nullptr if it has been just disabled by policy.
+  if (!service || service->IsFirstSetupComplete())

[Dan Beam, 2016/12/22 22:07:40]

nit: is there somehow we can check that if !service that we're disabled by
policy?

[tommycli, 2016/12/22 22:46:16]

Well... it's more like, GetSyncService() returns nullptr if
profile->IsSyncAllowed() is false:
https://codesearch.chromium.org/chromium/src/chrome/browser/ui/webui/settings...

So adding a DCHECK would be pretty tautological.

     return;
 
   // This is the first time configuring sync, so log it.