Offer user to send feedback from profile error dialog

sql/connection.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 SQL_CONNECTION_H_
 #define SQL_CONNECTION_H_
 
 #include <stddef.h>
 #include <stdint.h>
 #include <map>
@@ skipping 221 matching lines @@
   // results into |messages|.  Returns the success of running the
   // statement - per the SQLite documentation, if no errors are found the
   // call should succeed, and a single value "ok" should be in messages.
   bool FullIntegrityCheck(std::vector<std::string>* messages);
 
   // Runs "PRAGMA quick_check" and, unlike the FullIntegrityCheck method,
   // interprets the results returning true if the the statement executes
   // without error and results in a single "ok" value.
   bool QuickIntegrityCheck() WARN_UNUSED_RESULT;
 
+  // Meant to be called from a client error callback so that it's able to
+  // get diagnostic information about the database.
+  std::string GetDiagnosticInfo(int extended_error, Statement* statement);

[sky, 2016/07/27 15:12:56]

Is there a reason you don't provide the diagnostic string directly to the
callback? Seems more natural and less error prone.

[afakhry, 2016/07/27 18:53:55]

There are many SQLite errors:
https://cs.chromium.org/chromium/src/third_party/sqlite/amalgamation/sqlite3.....
We may not afford to collect the diagnostics on every single error. For the
profile errors, we only care about catastrophic errors (SQLITE_CORRUPT and
SQLITE_NOTADB)
(https://cs.chromium.org/chromium/src/components/history/core/browser/history_...)
at which point we will collect the diagnostics info. See history_backend.cc in
this CL. So I think leaving this function available to be called on-as-needed
basis is better. 

+
   // Initialization ------------------------------------------------------------
 
   // Initializes the SQL connection for the given file, returning true if the
   // file could be opened. You can call this or OpenInMemory.
   bool Open(const base::FilePath& path) WARN_UNUSED_RESULT;
 
   // Initializes the SQL connection for a temporary in-memory database. There
   // will be no associated file on disk, and the initial database will be
   // empty. You can call this or Open.
   bool OpenInMemory() WARN_UNUSED_RESULT;
@@ skipping 545 matching lines @@
 
   // Stores the dump provider object when db is open.
   std::unique_ptr<ConnectionMemoryDumpProvider> memory_dump_provider_;
 
   DISALLOW_COPY_AND_ASSIGN(Connection);
 };
 
 }  // namespace sql
 
 #endif  // SQL_CONNECTION_H_