Make BindStateBase constructor out-of-line

base/callback_internal.cc

Index: base/callback_internal.cc
diff --git a/base/callback_internal.cc b/base/callback_internal.cc
index ad88894e2685ec84c03a53c4647adfe8195b1719..303de4d71b84d148557f17bbf388cb35849e0622 100644
--- a/base/callback_internal.cc
+++ b/base/callback_internal.cc
@@ -9,6 +9,11 @@
 namespace base {
 namespace internal {
 
+BindStateBase::BindStateBase(InvokeFuncStorage polymorphic_invoke,
+                             void (*destructor)(BindStateBase*))
+      : polymorphic_invoke_(polymorphic_invoke),
+        ref_count_(0), destructor_(destructor) {}
+
 void BindStateBase::AddRef() {
   AtomicRefCountInc(&ref_count_);
 }