Disambiguate OnMouseCaptureLost from OnMouseReleased, etc.

views/controls/button/checkbox.cc

Index: views/controls/button/checkbox.cc
diff --git a/views/controls/button/checkbox.cc b/views/controls/button/checkbox.cc
index 693e282390110d01600087e55fa5a165ad6be465..8e3693e7aced0bd3f306ac1fd8ccd1e31f5710e6 100644
--- a/views/controls/button/checkbox.cc
+++ b/views/controls/button/checkbox.cc
@@ -131,14 +131,18 @@ bool Checkbox::OnMouseDragged(const MouseEvent& event) {
   return false;
 }
 
-void Checkbox::OnMouseReleased(const MouseEvent& event, bool canceled) {
+void Checkbox::OnMouseReleased(const MouseEvent& event) {
   native_wrapper_->SetPushed(false);
-  if (!canceled && HitTestLabel(event)) {
+  if (HitTestLabel(event)) {
     SetChecked(!checked());
     ButtonPressed();
   }
 }
 
+void Checkbox::OnMouseCaptureLost() {
+  native_wrapper_->SetPushed(false);
+}
+
 void Checkbox::OnMouseMoved(const MouseEvent& event) {
   native_wrapper_->SetPushed(HitTestLabel(event));
 }