RefCounted types should not have public destructors

base/threading/non_thread_safe.h

Index: base/threading/non_thread_safe.h
diff --git a/base/threading/non_thread_safe.h b/base/threading/non_thread_safe.h
index a104ae3d298391e68fdc9a80d6801a2e71d87177..74540573c1e282477d3ce90343ca979d96cbf821 100644
--- a/base/threading/non_thread_safe.h
+++ b/base/threading/non_thread_safe.h
@@ -62,11 +62,9 @@ class NonThreadSafeDoNothing {
 // NonThreadSafe. For more details about when to choose one over the other, see
 // the documentation for base::ThreadChecker.
 #if ENABLE_NON_THREAD_SAFE
-class NonThreadSafe : public NonThreadSafeImpl {
-};
+typedef NonThreadSafeImpl NonThreadSafe;

[jar (doing other things), 2012/07/09 16:51:45]

Can you motivate this change? This opens a tad more functionality than the old
code... so the question is: What methods or slots were you hoping to access on a
typedef'ed NonThreadSafe that you couldn't access when derived?
Perchance you should include the answer in a comment here.

[Ryan Sleevi, 2012/07/09 23:27:54]

More aptly, it closes functionality, not opens it up. Specifically, it doesn't
allow the C++ default (constructor, copy operator, destructor) to be created,
since they're all created at public visibility. Instead, it leaves the
visibility as specified by the the lower layer - which includes keeping the
destructor protected (rather than implicitly public)

[jar (doing other things), 2012/07/09 23:33:51]

SGTM (my confusion in my comment).

On 2012/07/09 23:27:54, Ryan Sleevi wrote:

 #else
-class NonThreadSafe : public NonThreadSafeDoNothing {
-};
+typedef NonThreadSafeDoNothing NonThreadsafe;

[Ryan Sleevi, 2012/07/09 23:27:54]

Incidentally, my shift-key appears to be broken on my home machine, and this
would not have shown up on try bots :-/

 #endif  // ENABLE_NON_THREAD_SAFE
 
 #undef ENABLE_NON_THREAD_SAFE