[Sync] Add support for dynamically enabling/disabling types

components/sync_driver/failed_data_types_handler.h

Index: components/sync_driver/failed_data_types_handler.h
diff --git a/components/sync_driver/failed_data_types_handler.h b/components/sync_driver/failed_data_types_handler.h
index bff7b15e5330a7723ca29376b526b84e1bc9f9ef..3820a247be990d5d9548c7cfd036ceac0f193c8e 100644
--- a/components/sync_driver/failed_data_types_handler.h
+++ b/components/sync_driver/failed_data_types_handler.h
@@ -32,13 +32,24 @@ class FailedDataTypesHandler {
   // Resets those persistence errors that intersect with |purged_types|.
   void ResetPersistenceErrorsFrom(syncer::ModelTypeSet purged_types);
 
+  // Removes |type| from the data_type_errors_ set. Returns true if the type
+  // was removed from the error set, false if the type did not have a data type
+  // error to begin with.
+  bool ResetDataTypeErrorFor(syncer::ModelType type);
+
+  // Removes |type| from the unread_errors_ set. Returns true if the type
+  // was removed from the error set, false if the type did not have an unready
+  // error to begin with.
+  bool ResetUnreadyErrorFor(syncer::ModelType type);
+
   // Returns a list of all the errors this class has recorded.
   TypeErrorMap GetAllErrors() const;
 
-  // Returns all types with errors.
+  // Returns all types with failure errors. This includes, fatal, crypto, and
+  // unready types.`
   syncer::ModelTypeSet GetFailedTypes() const;
 
-  // Returns the types that are failing due to startup or runtime errors.
+  // Returns the types that are failing due to unrecoverable or datatype errors.
   syncer::ModelTypeSet GetFatalErrorTypes() const;
 
   // Returns the types that are failing due to cryptographer errors.
@@ -47,21 +58,33 @@ class FailedDataTypesHandler {
   // Returns the types that are failing due to persistence errors.
   syncer::ModelTypeSet GetPersistenceErrorTypes() const;
 
+  // Returns the types that cannot be configured due to not being ready.
+  syncer::ModelTypeSet GetUnreadyErrorTypes() const;
+
  private:
   // Returns true if there are any types with errors.
   bool AnyFailedDataType() const;
 
-  // List of data types that failed at startup due to association errors or
-  // runtime due to data type errors.
-  TypeErrorMap fatal_errors_;
+  // List of data types that failed due to unrecoverable errors and should
+  // be disabled.
+  TypeErrorMap unrecoverable_errors_;
+
+  // List of data types that failed due to runtime errors and should be
+  // disabled. These are different from unrecoverable_errors_ in that
+  // ResetDataTypeError can remove them from this list.
+  TypeErrorMap data_type_errors_;
 
   // List of data types that failed due to the cryptographer not being ready.
   TypeErrorMap crypto_errors_;
 
-  // List of data type that failed because sync did not persist the newest
+  // List of data types that failed because sync did not persist the newest
   // version of their data.
   TypeErrorMap persistence_errors_;
 
+  // List of data types that could not start due to not being ready. These can
+  // be marked as ready by calling ResetUnreadyErrorFor(..).
+  TypeErrorMap unready_errors_;
+
   DISALLOW_COPY_AND_ASSIGN(FailedDataTypesHandler);
 };