Pass a RemovalCause to CookieChangedCallback

net/cookies/cookie_store.h

Index: net/cookies/cookie_store.h
diff --git a/net/cookies/cookie_store.h b/net/cookies/cookie_store.h
index f56fedd90392877b24e554276579a12733617700..f9d62a215f79a58b1f604a1ed03394cb366c2ec5 100644
--- a/net/cookies/cookie_store.h
+++ b/net/cookies/cookie_store.h
@@ -33,14 +33,29 @@ class CookieMonster;
 // Destroying the CookieStore will cancel pending async callbacks.
 class NET_EXPORT CookieStore {
  public:
+  // In a CookieChangedCallback, this indicates why a cookie was removed if it
+  // was removed. This roughly mirrors CookieMonster::DeletionCause and
+  // CookieMonsterDelegate::ChangeCause.
+  enum class RemovalCause {
+    NOT_REMOVED,

[Roger Tawa OOO till Jul 10th, 2016/09/19 20:23:02]

If I have a value set for a cookie, and I browse to a website which returns a
Set-Cookie header, will I get only a NOT_REMOVED notif, or an EXPLICIT or
OVERWRITE notif followed by a NOT_REMOVED?

[nharper, 2016/09/19 21:34:30]

It looks like you'll first get a (removed=true) OVERWRITE followed by a
(removed=false) EXPLICIT (or NOT_REMOVED as currently implemented) - afaict that
behavior is implemented by removing the existing value and then inserting the
new value.

+    UNKNOWN,
+    EXPLICIT,
+    OVERWRITE,
+    EXPIRED,
+    EVICTED,
+    EXPIRED_OVERWRITE,
+  };

[Roger Tawa OOO till Jul 10th, 2016/09/19 20:23:02]

Wondering why you didn't define as ChangeCause instead, or maybe merge with
CookieMonsterDelegate::ChangeCause.  You could then remove the |bool removed|
from the callback signature.  If you changed all calls to the callback with:

removed=false
cause=UNKNOWN

to be just cause=NOT_REMOVED that would accomplish the same without the bool
arg.  Yes/no?

[nharper, 2016/09/19 21:34:30]

I'm thinking combining the bool with the enum would make sense. I'm less sure
about combining this enum with CookieMonsterDelegate::ChangeCause - let me ask
on net-dev what people think.

+
   // Callback definitions.
   typedef base::Callback<void(const CookieList& cookies)> GetCookieListCallback;
   typedef base::Callback<void(const std::string& cookie)> GetCookiesCallback;
   typedef base::Callback<void(bool success)> SetCookiesCallback;
   typedef base::Callback<void(int num_deleted)> DeleteCallback;
-  typedef base::Callback<void(const CanonicalCookie& cookie, bool removed)>
+  typedef base::Callback<
+      void(const CanonicalCookie& cookie, bool removed, RemovalCause cause)>
       CookieChangedCallback;
-  typedef base::CallbackList<void(const CanonicalCookie& cookie, bool removed)>
+  typedef base::CallbackList<
+      void(const CanonicalCookie& cookie, bool removed, RemovalCause cause)>
       CookieChangedCallbackList;
   typedef CookieChangedCallbackList::Subscription CookieChangedSubscription;
   typedef base::Callback<bool(const CanonicalCookie& cookie)> CookiePredicate;