Directly call ExtensionManagementFactory::GetForBrowserContext

there is no reason to call ExtensionManagementFactory::GetInstance to
access it. More, GetForBrowserContext calls GetInstance itself.

ExtensionManagementFactory: :GetForBrowserContext is a static method, so
Change-Id: Ib761361258047b144edc8c2ee725c2b1811f6697
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1724511
Reviewed-by: Devlin <[email protected]>
Reviewed-by: Pavol Marko <[email protected]>
Commit-Queue: Oleg Davydov <[email protected]>
Cr-Commit-Position: refs/heads/master@{#682296}
diff --git a/chrome/browser/extensions/extension_service.cc b/chrome/browser/extensions/extension_service.cc
index f46f29a..8e931b2a 100644
--- a/chrome/browser/extensions/extension_service.cc
+++ b/chrome/browser/extensions/extension_service.cc
@@ -376,9 +376,8 @@
 }
 
 void ExtensionService::Shutdown() {
-  ExtensionManagementFactory::GetInstance()
-      ->GetForBrowserContext(profile())
-      ->RemoveObserver(this);
+  ExtensionManagementFactory::GetForBrowserContext(profile())->RemoveObserver(
+      this);
 }
 
 const Extension* ExtensionService::GetExtensionById(