Track empty username and password in PasswordStore.

components/password_manager/core/browser/login_database.cc

Index: components/password_manager/core/browser/login_database.cc
diff --git a/components/password_manager/core/browser/login_database.cc b/components/password_manager/core/browser/login_database.cc
index 4fbd3b2279808b2830ce08fe2a25c987f7337697..3450a41ed2b0fb1642580dc79a78b47ba9a3015d 100644
--- a/components/password_manager/core/browser/login_database.cc
+++ b/components/password_manager/core/browser/login_database.cc
@@ -8,6 +8,7 @@
 #include <limits>
 
 #include "base/bind.h"
+#include "base/debug/dump_without_crashing.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
@@ -109,6 +110,12 @@ void AddCallback(int err, sql::Statement* /*stmt*/) {
     DLOG(WARNING) << "LoginDatabase::AddLogin updated an existing form";
 }
 
+// http://crbug.com/404012. Let's see where the empty fields come from.
+void CheckEmptyUsernameAndPassword(const PasswordForm& form) {

[Ilya Sherman, 2014/08/22 03:54:29]

nit: "Check" -> "CheckFor"

[vasilii, 2014/08/22 09:32:25]

Done.

+  if (form.username_value.empty() && form.password_value.empty())
+    base::debug::DumpWithoutCrashing();

[Ilya Sherman, 2014/08/22 03:54:29]

I don't really know how this code works.  According to the comment in the
header, you should first call SetDumpWithoutCrashingFunction().

What happens with the dump?  Does it get uploaded to the crash server?  Or does
it just remain local to the system that generated it?

[vasilii, 2014/08/22 09:32:25]

This callback is a platform dependent Breakpad method. I copied this function
from browser_sync::ChromeReportUnrecoverableError() in sync. For sync it uploads
the report for sure.

+}
+
 }  // namespace
 
 LoginDatabase::LoginDatabase() {
@@ -331,6 +338,7 @@ void LoginDatabase::ReportMetrics(const std::string& sync_username) {
 }
 
 PasswordStoreChangeList LoginDatabase::AddLogin(const PasswordForm& form) {
+  CheckEmptyUsernameAndPassword(form);
   PasswordStoreChangeList list;
   std::string encrypted_password;
   if (EncryptedString(form.password_value, &encrypted_password) !=
@@ -372,6 +380,7 @@ PasswordStoreChangeList LoginDatabase::AddLogin(const PasswordForm& form) {
 }
 
 PasswordStoreChangeList LoginDatabase::UpdateLogin(const PasswordForm& form) {
+  CheckEmptyUsernameAndPassword(form);
   std::string encrypted_password;
   if (EncryptedString(form.password_value, &encrypted_password) !=
           ENCRYPTION_RESULT_SUCCESS)