Devirtualize base::BindState to save ~1% of Chrome's binary size (~1MB)

base/callback_unittest.cc

Index: base/callback_unittest.cc
diff --git a/base/callback_unittest.cc b/base/callback_unittest.cc
index 5644b8515f0e538942d69c945cae2b56b0a075cd..2844aa98a29317149eaaf493b3d9f92b3f7fff0b 100644
--- a/base/callback_unittest.cc
+++ b/base/callback_unittest.cc
@@ -35,9 +35,13 @@ template <>
 struct BindState<void(void), void(void), void(FakeInvoker)>
     : public BindStateBase {
  public:
+  BindState() : BindStateBase(&Destroy) {}
   typedef FakeInvoker InvokerType;
  private:
-  ~BindState() override {}
+  ~BindState() {}
+  static void Destroy(BindStateBase* self) {
+    delete static_cast<BindState*>(self);
+  }
 };
 
 template <>
@@ -45,9 +49,13 @@ struct BindState<void(void), void(void),
                            void(FakeInvoker, FakeInvoker)>
     : public BindStateBase {
  public:
+  BindState() : BindStateBase(&Destroy) {}
   typedef FakeInvoker InvokerType;
  private:
-  ~BindState() override {}
+  ~BindState() {}
+  static void Destroy(BindStateBase* self) {
+    delete static_cast<BindState*>(self);
+  }
 };
 }  // namespace internal