Cleanup: Remove unused variables in chrome/ found by Scythe.

chrome/browser/sessions/session_restore.h

Index: chrome/browser/sessions/session_restore.h
diff --git a/chrome/browser/sessions/session_restore.h b/chrome/browser/sessions/session_restore.h
index d38828494ea579628f45e016003d13d27dbbd072..e6cb7819e514e7319d77cb150a8902ad28df3234 100644
--- a/chrome/browser/sessions/session_restore.h
+++ b/chrome/browser/sessions/session_restore.h
@@ -98,10 +98,6 @@ class SessionRestore {
   static CallbackSubscription RegisterOnSessionRestoredCallback(
       const base::Callback<void(int)>& callback);
 
-  // The max number of non-selected tabs SessionRestore loads when restoring
-  // a session. A value of 0 indicates all tabs are loaded at once.
-  static size_t num_tabs_to_load_;
-
  private:
   SessionRestore();