Start BindStateBase ref count from 1 instead of 0

base/callback_internal.cc

Index: base/callback_internal.cc
diff --git a/base/callback_internal.cc b/base/callback_internal.cc
index 3a665d28cae8fc6d5280acad88313de0a8a8ec41..a760f0664c214a7c504f448da5ef224e66f129c2 100644
--- a/base/callback_internal.cc
+++ b/base/callback_internal.cc
@@ -74,9 +74,8 @@ bool CallbackBase<CopyMode::MoveOnly>::EqualsInternal(
   return bind_state_ == other.bind_state_;
 }
 
-CallbackBase<CopyMode::MoveOnly>::CallbackBase(
-    BindStateBase* bind_state)
-    : bind_state_(bind_state) {
+CallbackBase<CopyMode::MoveOnly>::CallbackBase(BindStateBase* bind_state)
+    : bind_state_(bind_state ? AdoptRef(bind_state) : nullptr) {

[dcheng, 2017/03/30 21:15:25]

Can you remind me when we would bind a null state here? Codesearch doesn't work
for this.

[tzik, 2017/03/31 13:30:59]

It's null when it's called from the default constructor of Callback.
https://cs.chromium.org/chromium/src/base/callback.h?q=callback.h&dr=CSs&l=47

   DCHECK(!bind_state_.get() || bind_state_->HasOneRef());
 }