Prefer the exact match over prefix match for the password manager filling.

components/autofill/content/renderer/password_autofill_agent.cc

 // Copyright 2013 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.
 
 #include "components/autofill/content/renderer/password_autofill_agent.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <memory>
@@ skipping 434 matching lines @@
 
   base::string16 current_username;
   if (!username_element->IsNull()) {
     current_username = username_element->Value().Utf16();
   }
 
   // username and password will contain the match found if any.
   base::string16 username;
   base::string16 password;
 
-  FindMatchesByUsername(fill_data, current_username, exact_username_match,
-                        logger, &username, &password);
+  FindMatchesByUsername(fill_data, current_username,
+                        true /* exact_username_match */, logger, &username,
+                        &password);
+
+  if (!exact_username_match && password.empty()) {
+    FindMatchesByUsername(fill_data, current_username, exact_username_match,
+                          logger, &username, &password);
+  }
 
   if (password.empty())
     return false;
 
   // TODO(tkent): Check maxlength and pattern for both username and password
   // fields.
 
   // Input matches the username, fill in required values.
   if (!username_element->IsNull() &&
       IsElementAutocompletable(*username_element)) {
@@ skipping 1317 matching lines @@
 PasswordAutofillAgent::GetPasswordManagerDriver() {
   if (!password_manager_driver_) {
     render_frame()->GetRemoteInterfaces()->GetInterface(
         mojo::MakeRequest(&password_manager_driver_));
   }
 
   return password_manager_driver_;
 }
 
 }  // namespace autofill