Update SupportsUserData uses with unique_ptr.

components/zoom/zoom_event_manager.cc

Index: components/zoom/zoom_event_manager.cc
diff --git a/components/zoom/zoom_event_manager.cc b/components/zoom/zoom_event_manager.cc
index c1fd61cdd7315b9a55fa8dc24d51cc96f4469221..cdb88db6401f6eb2a60e92ea7fb53ee58c493872 100644
--- a/components/zoom/zoom_event_manager.cc
+++ b/components/zoom/zoom_event_manager.cc
@@ -4,6 +4,7 @@
 
 #include "components/zoom/zoom_event_manager.h"
 
+#include "base/memory/ptr_util.h"
 #include "components/zoom/zoom_event_manager_observer.h"
 #include "content/public/browser/browser_context.h"
 
@@ -15,8 +16,10 @@ namespace zoom {
 
 ZoomEventManager* ZoomEventManager::GetForBrowserContext(
     content::BrowserContext* context) {
-  if (!context->GetUserData(kBrowserZoomEventManager))
-    context->SetUserData(kBrowserZoomEventManager, new ZoomEventManager);
+  if (!context->GetUserData(kBrowserZoomEventManager)) {
+    context->SetUserData(kBrowserZoomEventManager,
+                         base::MakeUnique<ZoomEventManager>());
+  }
   return static_cast<ZoomEventManager*>(
       context->GetUserData(kBrowserZoomEventManager));
 }