Implement ScopedRunnableMethodFactory using WeakPtr.

This required some changes to WeakPtr to support the addition
of WeakPtrFactory::HasWeakPtrs(), which is used to implement
ScopedRunnableMethodFactory::empty().

Now, the WeakReferenceOwner just holds a pointer to the Flag
class, and the Flag holds a back-pointer that it can use to
clear the WeakReferenceOwner's pointer when the Flag is
destroyed.  I use the null'ness of this back-pointer in place
of the bool member that was previously used to indicate if the
WeakReference is valid.

It was also necessary to expose a HasOneRef method on
RefCounted.  I included one on RefCountedThreadSafe for
completeness.

Finally, I switched HttpCache over to using WeakPtr instead
of RevocableStore so that I could delete RevocableStore.

(I'm making this change to consolidate similar functionality.)

R=abarth
BUG=none
TEST=none

Review URL: http://codereview.chromium.org/235027

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@27287 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 6 insertions, 0 deletions

diff --git a/base/ref_counted.h b/base/ref_counted.h
index 79f9f55..097d16e 100644
--- a/base/ref_counted.h
+++ b/base/ref_counted.h
@@ -13,6 +13,9 @@ namespace base {
 namespace subtle {
 
 class RefCountedBase {
+ public:
+  bool HasOneRef() const { return ref_count_ == 1; }
+
  protected:
   RefCountedBase();
   ~RefCountedBase();
@@ -34,6 +37,9 @@ class RefCountedBase {
 };
 
 class RefCountedThreadSafeBase {
+ public:
+  bool HasOneRef() const;
+
  protected:
   RefCountedThreadSafeBase();
   ~RefCountedThreadSafeBase();