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

base/callback_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/callback_helpers.h"
 #include "base/callback_internal.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 17 matching lines @@
 
 // White-box testpoints to inject into a Callback<> object for checking
 // comparators and emptiness APIs.  Use a BindState that is specialized
 // based on a type we declared in the anonymous namespace above to remove any
 // chance of colliding with another instantiation and breaking the
 // one-definition-rule.
 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 <>
 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
 
 namespace {
 
 typedef internal::BindState<void(void), void(void), void(FakeInvoker)>
     FakeBindState1;
 typedef internal::BindState<void(void), void(void),
                             void(FakeInvoker, FakeInvoker)>
    FakeBindState2;
@@ skipping 114 matching lines @@
 
 TEST_F(CallbackTest, CallbackHasLastRefOnContainingObject) {
   bool deleted = false;
   CallbackOwner* owner = new CallbackOwner(&deleted);
   owner->Reset();
   ASSERT_TRUE(deleted);
 }
 
 }  // namespace
 }  // namespace base