Fix auto raw pointer deduction on linux

extensions/browser/api/system_display/system_display_api.cc

Index: extensions/browser/api/system_display/system_display_api.cc
diff --git a/extensions/browser/api/system_display/system_display_api.cc b/extensions/browser/api/system_display/system_display_api.cc
index a12d23715c4b7c02562e4a558a73b7fc2fd25e72..820e2fbb8d703f0786509c3fd3d95dba9ebac78e 100644
--- a/extensions/browser/api/system_display/system_display_api.cc
+++ b/extensions/browser/api/system_display/system_display_api.cc
@@ -142,7 +142,7 @@ OverscanTracker::OverscanWebObserver* OverscanTracker::GetObserver(
   if (!create)
     return nullptr;
   auto owned_observer = base::MakeUnique<OverscanWebObserver>(web_contents);
-  auto observer_ptr = owned_observer.get();
+  auto* observer_ptr = owned_observer.get();
   observers_[web_contents] = std::move(owned_observer);
   return observer_ptr;
 }