Offer user to send feedback from profile error dialog

components/history/core/browser/history_backend.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_BACKEND_H_
 #define COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_BACKEND_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 95 matching lines @@
  public:
   // Interface implemented by the owner of the HistoryBackend object. Normally,
   // the history service implements this to send stuff back to the main thread.
   // The unit tests can provide a different implementation if they don't have
   // a history service object.
   class Delegate {
    public:
     virtual ~Delegate() {}
 
     // Called when the database cannot be read correctly for some reason.
-    virtual void NotifyProfileError(sql::InitStatus init_status) = 0;
+    // |diagnostics| will contain information about the underlying database

[sky, 2016/08/02 13:27:21]

nit: 'will contain' -> contains

[afakhry, 2016/08/02 23:58:24]

Done.

+    // which can help in identifying the cause of the profile error.
+    virtual void NotifyProfileError(sql::InitStatus init_status,
+                                    const std::string& diagnostics) = 0;
 
     // Sets the in-memory history backend. The in-memory backend is created by
     // the main backend. For non-unit tests, this happens on the background
     // thread. It is to be used on the main thread, so this would transfer
     // it to the history service. Unit tests can override this behavior.
     //
     // This function is NOT guaranteed to be called. If there is an error,
     // there may be no in-memory database.
     virtual void SetInMemoryBackend(
         std::unique_ptr<InMemoryHistoryBackend> backend) = 0;
@@ skipping 745 matching lines @@
   // of inheritance from base::SupportsUserData).
   std::unique_ptr<HistoryBackendHelper> supports_user_data_helper_;
 
   // Used to manage syncing of the typed urls datatype. This will be null before
   // Init is called.
   std::unique_ptr<TypedUrlSyncableService> typed_url_syncable_service_;
 
   // Listens for the system being under memory pressure.
   std::unique_ptr<base::MemoryPressureListener> memory_pressure_listener_;
 
+  // Contains diagnostic information about the sql database that will be filled

[sky, 2016/08/02 13:27:21]

nit: 'will be filled' -> is non-empty

[afakhry, 2016/08/02 23:58:24]

Done.

+  // when a catastrophic error occurs.
+  std::string db_diagnostics_;
+
   // Map from host to index in the TopHosts list. It is updated only by
   // TopHosts(), so it's usually stale.
   mutable base::hash_map<std::string, int> host_ranks_;
 
   // List of observers
   base::ObserverList<HistoryBackendObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryBackend);
 };
 
 }  // namespace history
 
 #endif  // COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_BACKEND_H_