Implement cloud policy invalidations using the invalidation service framework.

chrome/browser/policy/cloud/cloud_policy_validator.h

Index: chrome/browser/policy/cloud/cloud_policy_validator.h
diff --git a/chrome/browser/policy/cloud/cloud_policy_validator.h b/chrome/browser/policy/cloud/cloud_policy_validator.h
index d53a0c6f91327664d10a157818a61085a7a542e0..9907dac9305fb66ca071e6b38c6c55f01c241432 100644
--- a/chrome/browser/policy/cloud/cloud_policy_validator.h
+++ b/chrome/browser/policy/cloud/cloud_policy_validator.h
@@ -101,6 +101,12 @@ class CloudPolicyValidatorBase {
     return policy_data_;
   }
 
+  // If ValidateHashValue() is called, the hash value of the policy value can
+  // be read with this method after completion has been signaled.
+  uint32 hash_value() const {
+    return hash_value_;
+  }
+
   // Instructs the validator to check that the policy timestamp is not before
   // |not_before| and not after |now| + grace interval. If
   // |timestamp_option| is set to TIMESTAMP_REQUIRED, then the policy will fail
@@ -145,6 +151,10 @@ class CloudPolicyValidatorBase {
   // check against.
   void ValidateInitialKey();
 
+  // Causes the validator to calculate the hash value of the policy value.
+  // This can be used to determine if two policies are different.
+  void ValidateHashValue();
+
   // Convenience helper that configures timestamp and token validation based on
   // the current policy blob. |policy_data| may be NULL, in which case the
   // timestamp validation will drop the lower bound. |dm_token_option|
@@ -182,6 +192,7 @@ class CloudPolicyValidatorBase {
     VALIDATE_PAYLOAD     = 1 << 6,
     VALIDATE_SIGNATURE   = 1 << 7,
     VALIDATE_INITIAL_KEY = 1 << 8,
+    VALIDATE_HASH_VALUE  = 1 << 9,
   };
 
   // Performs validation, called on a background thread.
@@ -207,6 +218,7 @@ class CloudPolicyValidatorBase {
   Status CheckPayload();
   Status CheckSignature();
   Status CheckInitialKey();
+  Status CheckHashValue();
 
   // Verifies the SHA1/RSA |signature| on |data| against |key|.
   static bool VerifySignature(const std::string& data,
@@ -217,6 +229,7 @@ class CloudPolicyValidatorBase {
   scoped_ptr<enterprise_management::PolicyFetchResponse> policy_;
   scoped_ptr<enterprise_management::PolicyData> policy_data_;
   google::protobuf::MessageLite* payload_;
+  uint32 hash_value_;
 
   int validation_flags_;
   int64 timestamp_not_before_;