struct UnloadedExtensionInfo -> enum UnloadedExtensionInfoReason

We don't need to keep struct UnloadedExtensionInfo.
So removing it and use enum UnloadedExtensionInfoReason instead.

TEST=Everything runs smoothly
BUG=715144

Review-Url: https://codereview.chromium.org/2839373003
Cr-Commit-Position: refs/heads/master@{#469065}
diff --git a/chrome/browser/extensions/extension_gcm_app_handler.h b/chrome/browser/extensions/extension_gcm_app_handler.h
index 33f03ed..8201a678 100644
--- a/chrome/browser/extensions/extension_gcm_app_handler.h
+++ b/chrome/browser/extensions/extension_gcm_app_handler.h
@@ -82,7 +82,7 @@
                          const Extension* extension) override;
   void OnExtensionUnloaded(content::BrowserContext* browser_context,
                            const Extension* extension,
-                           UnloadedExtensionInfo::Reason reason) override;
+                           UnloadedExtensionReason reason) override;
   void OnExtensionUninstalled(content::BrowserContext* browser_context,
                               const Extension* extension,
                               extensions::UninstallReason reason) override;