Offer user to send feedback from profile error dialog

sql/connection.h

Index: sql/connection.h
diff --git a/sql/connection.h b/sql/connection.h
index 12e7041c9fd2fa10f7bec8c04b182c14c5d302ad..5b8d39964ab2aa4e96312b790606c7b0bd0c8b29 100644
--- a/sql/connection.h
+++ b/sql/connection.h
@@ -239,6 +239,10 @@ class SQL_EXPORT Connection {
   // 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