Decouple RulesCacheDelegate from RulesRegistry

chrome/browser/extensions/api/declarative/rules_registry.h

Index: chrome/browser/extensions/api/declarative/rules_registry.h
diff --git a/chrome/browser/extensions/api/declarative/rules_registry.h b/chrome/browser/extensions/api/declarative/rules_registry.h
index c8546cc52659f6d5eb7b33b99554e3895f70b90e..f6ec6ea924160d3ac5632ad79696e94e99abd3cf 100644
--- a/chrome/browser/extensions/api/declarative/rules_registry.h
+++ b/chrome/browser/extensions/api/declarative/rules_registry.h
@@ -44,21 +44,22 @@ class RulesRegistry : public base::RefCountedThreadSafe<RulesRegistry> {
   enum Defaults { DEFAULT_PRIORITY = 100 };
   // After the RulesCacheDelegate object (the part of the registry which runs on
   // the UI thread) is created, a pointer to it is passed to |*ui_part|.
-  // If |log_storage_init_delay| is set, the delay caused by loading and
-  // registering rules on initialization will be logged with UMA.
   // In tests, |profile| and |ui_part| can be NULL (at the same time). In that
   // case the storage functionality disabled (no RulesCacheDelegate object
-  // created) and the |log_storage_init_delay| flag is ignored.
+  // created).
   RulesRegistry(Profile* profile,
                 const std::string& event_name,
-                content::BrowserThread::ID owner_thread,
-                bool log_storage_init_delay,
-                scoped_ptr<RulesCacheDelegate>* ui_part);
+                content::BrowserThread::ID owner_thread);
 
   const OneShotEvent& ready() const {
     return ready_;
   }
 
+  base::WeakPtr<RulesRegistry> GetWeakPtr() {

[Jeffrey Yasskin, 2013/11/01 00:15:09]

It's good to avoid passing WeakPtrs out of the class when possible. Can we
organize ownership so we don't need this anymore?

Probably not in this CL.

[Fady Samuel, 2013/11/01 15:13:39]

I'll take care of this in a subsequent CL. Thanks!

+    DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
+    return weak_ptr_factory_.GetWeakPtr();
+  }
+
   // RulesRegistry implementation:
 
   // Registers |rules|, owned by |extension_id| to this RulesRegistry.
@@ -119,10 +120,17 @@ class RulesRegistry : public base::RefCountedThreadSafe<RulesRegistry> {
   // and all rules of this extension need to be removed.
   void OnExtensionUnloaded(const std::string& extension_id);
 
+  // Assigns a RulesCacheDelegate to this RulesRegistry. This delegate is
+  // responsible for storing the rules and retreiving them.
+  bool SetCacheDelegate(base::WeakPtr<RulesCacheDelegate> cache_delegate);

[Jeffrey Yasskin, 2013/11/01 00:15:09]

I think it's safe to pass WeakPtrs by reference, which can avoid some refcount
operations.

[Jeffrey Yasskin, 2013/11/01 00:15:09]

For functions that return bool, you need to say what the return value means.
However, I think in this case it'd be better to CHECK or DCHECK and return void,
since it's a programming error to set the cache delegate twice.

[Fady Samuel, 2013/11/01 15:13:39]

Done.

[Fady Samuel, 2013/11/01 15:13:39]

Done.

+
   // Returns the number of entries in used_rule_identifiers_ for leak detection.
   // Every ExtensionId counts as one entry, even if it contains no rules.
   size_t GetNumberOfUsedRuleIdentifiersForTesting() const;
 
+  // Returns the profile where the rules registry lives.
+  Profile* profile() const { return profile_; }
+
   // Returns the ID of the thread on which the rules registry lives.
   // It is safe to call this function from any thread.
   content::BrowserThread::ID owner_thread() const { return owner_thread_; }
@@ -174,11 +182,8 @@ class RulesRegistry : public base::RefCountedThreadSafe<RulesRegistry> {
   // Process the callbacks once the registry gets ready.
   void MarkReady(base::Time storage_init_time);
 
-  // Deserialize the rules from the given Value object and add them to the
-  // RulesRegistry.
-  void DeserializeAndAddRules(const std::string& extension_id,
-                              scoped_ptr<base::Value> rules);
-
+  // The profile to which this rules registry belongs.
+  Profile* profile_;
 
   // The ID of the thread on which the rules registry lives.
   const content::BrowserThread::ID owner_thread_;
@@ -203,7 +208,7 @@ class RulesRegistry : public base::RefCountedThreadSafe<RulesRegistry> {
   // destroyed on its thread, the use of the |cache_delegate_| would not be
   // safe. The registry only ever associates with one RulesCacheDelegate
   // instance.
-  const base::WeakPtr<RulesCacheDelegate> cache_delegate_;
+  base::WeakPtr<RulesCacheDelegate> cache_delegate_;
 
   ProcessChangedRulesState process_changed_rules_requested_;