Fix WeakPtrFactory member placement

Changing in the intialization order of WeakPtrFactory in src/chrome/browser module
such that all member variables should appear before the WeakPtrFactory
to ensure that any WeakPtrs to Controller are invalidated before its members
variable's destructors are executed, rendering them invalid.

BUG=303818

Review URL: https://codereview.chromium.org/582633002

Cr-Commit-Position: refs/heads/master@{#296007}

content/browser/frame_host/interstitial_page_impl.h

@@ -282,10 +282,10 @@ class CONTENT_EXPORT InterstitialPageImpl
 
   scoped_ptr<InterstitialPageDelegate> delegate_;
 
-  base::WeakPtrFactory<InterstitialPageImpl> weak_ptr_factory_;
-
   scoped_refptr<SessionStorageNamespace> session_storage_namespace_;
 
+  base::WeakPtrFactory<InterstitialPageImpl> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(InterstitialPageImpl);
 };