[sql] Log tag with sqlite errors.

sql/connection.cc

Index: sql/connection.cc
diff --git a/sql/connection.cc b/sql/connection.cc
index 097edd7a1ea2f57350869b2c4eaedb12db6b6bc1..9cef1bc0be867964df77174326fe8e46b379703e 100644
--- a/sql/connection.cc
+++ b/sql/connection.cc
@@ -1027,7 +1027,7 @@ int Connection::OnSqliteError(int err, sql::Statement *stmt) {
   AddTaggedHistogram("Sqlite.Error", err);
 
   // Always log the error.
-  LOG(ERROR) << "sqlite error " << err
+  LOG(ERROR) << histogram_tag_ << " sqlite error " << err

[Greg Spencer (Chromium), 2013/09/25 18:36:30]

Would it make sense to use sqlite3_column_database_name to get the database name
from the statement?

Otherwise, I agree with you that we don't want untagged ops.

[Scott Hess - ex-Googler, 2013/09/25 19:37:04]

http://www.sqlite.org/c3ref/column_database_name.html says they are only enabled
if compiled the right way.  Also, thinking on it, I bet there isn't even a
statement for these errors, it's probably failing even accessing the schema
info.

More achievable might be to add a line for sqlite3_sql() if stmt is non-NULL. 
That would not cover calls to Execute(), though... but it would probably be easy
to modify things to hit that case, too.  That should make it pretty easy to
backtrack to which caller is calling it, for all the good that will do.

OK, I'm going to tweak things a little more.

              << ", errno " << GetLastErrno()
              << ": " << GetErrorMessage();