Assert that thread-safe reference counting is used with

cross-thread NewRunnableMethod.

This assertion caught such an error in VisitedLinkMaster!

My approach, modify RunnableMethodTraits<T> to assert that
when ReleaseCallee happens on a different thread from
RetainCallee that the type supports thread-safe reference
counting.  I do this by adding a static method to both
RefCounted<T> and RefCountedThreadSafe<T>.

This results in a little ugliness in cases where people
implement AddRef and Release by hand (to make the no-ops).
There may be a nicer way to deal with those few cases.

R=brettw
BUG=none
TEST=none

Review URL: http://codereview.chromium.org/251012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@27379 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 5 insertions, 8 deletions

diff --git a/chrome/browser/chrome_plugin_host.cc b/chrome/browser/chrome_plugin_host.cc
index 1b62b9a..bfb5852 100644
--- a/chrome/browser/chrome_plugin_host.cc
+++ b/chrome/browser/chrome_plugin_host.cc
@@ -367,14 +367,11 @@ class ModelessHtmlDialogDelegate : public HtmlDialogUIDelegate {
 
 // Allows InvokeLater without adding refcounting.  The object is only deleted
 // when its last InvokeLater is run anyway.
-template<>
-void RunnableMethodTraits<ModelessHtmlDialogDelegate>::RetainCallee(
-    ModelessHtmlDialogDelegate* remover) {
-}
-template<>
-void RunnableMethodTraits<ModelessHtmlDialogDelegate>::ReleaseCallee(
-    ModelessHtmlDialogDelegate* remover) {
-}
+template <>
+struct RunnableMethodTraits<ModelessHtmlDialogDelegate> {
+  void RetainCallee(ModelessHtmlDialogDelegate*) {}
+  void ReleaseCallee(ModelessHtmlDialogDelegate*) {}
+};
 
 namespace {