Implement fetching, caching and retrieval of external policy data

chrome/browser/policy/cloud/cloud_policy_store.h

Index: chrome/browser/policy/cloud/cloud_policy_store.h
diff --git a/chrome/browser/policy/cloud/cloud_policy_store.h b/chrome/browser/policy/cloud/cloud_policy_store.h
index fee92b7218d9a30f3d35901cd2dc2ff838138904..bd7e27193d3e0525d17492e2f0b5f54af60ac2f4 100644
--- a/chrome/browser/policy/cloud/cloud_policy_store.h
+++ b/chrome/browser/policy/cloud/cloud_policy_store.h
@@ -7,6 +7,7 @@
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "chrome/browser/policy/cloud/cloud_policy_validator.h"
 #include "chrome/browser/policy/policy_map.h"
@@ -14,6 +15,8 @@
 
 namespace policy {
 
+class CloudExternalDataManager;
+
 // Defines the low-level interface used by the cloud policy code to:
 //   1. Validate policy blobs that should be applied locally
 //   2. Persist policy blobs
@@ -57,6 +60,10 @@ class CloudPolicyStore {
   // accomplished by calling Load() after startup.
   bool is_initialized() const { return is_initialized_; }
 
+  base::WeakPtr<CloudExternalDataManager> external_data_manager() const {
+    return external_data_manager_;
+  }
+
   const PolicyMap& policy_map() const { return policy_map_; }
   bool has_policy() const {
     return policy_.get() != NULL;
@@ -93,11 +100,20 @@ class CloudPolicyStore {
   // Removes the specified observer.
   void RemoveObserver(Observer* observer);
 
+  // Indicate that external data referenced by policies in this store is managed
+  // by |external_data_manager|. The |external_data_manager| will be notified
+  // about policy changes before any other observers.
+  void SetExternalDataManager(
+      base::WeakPtr<CloudExternalDataManager> external_data_manager);
+
  protected:
   // Invokes the corresponding callback on all registered observers.
   void NotifyStoreLoaded();
   void NotifyStoreError();
 
+  // Manages external data referenced by policies.
+  base::WeakPtr<CloudExternalDataManager> external_data_manager_;
+
   // Decoded version of the currently effective policy.
   PolicyMap policy_map_;