Track password field id so it can be used to improve uniqueness of passwordId

chrome/browser/resources/gaia_auth/saml_injected.js

Index: chrome/browser/resources/gaia_auth/saml_injected.js
diff --git a/chrome/browser/resources/gaia_auth/saml_injected.js b/chrome/browser/resources/gaia_auth/saml_injected.js
index ae56f5cc537cce99829cb5b6cb8a1c892306fb11..a4279c6c2bfb11fcb027ca54a096b558a9d56488 100644
--- a/chrome/browser/resources/gaia_auth/saml_injected.js
+++ b/chrome/browser/resources/gaia_auth/saml_injected.js
@@ -143,8 +143,9 @@
         return;
 
       var index = this.passwordFields_.length;
+      var fieldId = passwordField.id;

[xiyuan, 2016/06/10 17:05:58]

It is possible that the IdP page does not set "id" for the password field. Let's
give it some fall back values, something like,

var fieldId = passwordField.id || passwordField.name || '';

       passwordField.addEventListener(
-          'input', this.onPasswordChanged_.bind(this, index));
+          'input', this.onPasswordChanged_.bind(this, index, fieldId));
       this.passwordFields_.push(passwordField);
       this.passwordValues_.push(passwordField.value);
     },
@@ -153,16 +154,18 @@
      * Check if the password field at |index| has changed. If so, sends back
      * the updated value.
      */
-    maybeSendUpdatedPassword: function(index) {
+    maybeSendUpdatedPassword: function(index, fieldId) {
       var newValue = this.passwordFields_[index].value;
       if (newValue == this.passwordValues_[index])
         return;
 
       this.passwordValues_[index] = newValue;
 
-      // Use an invalid char for URL as delimiter to concatenate page url and
-      // password field index to construct a unique ID for the password field.
-      var passwordId = this.pageURL_.split('#')[0].split('?')[0] + '|' + index;
+      // Use an invalid char for URL as delimiter to concatenate page url,
+      // password field index and id to construct a unique ID for the password
+      // field.
+      var passwordId = this.pageURL_.split('#')[0].split('?')[0] +
+          '|' + index + '|' + fieldId;
       this.channel_.send({
         name: 'updatePassword',
         id: passwordId,
@@ -175,8 +178,8 @@
      * @param {number} index The index of the password fields in
      *     |passwordFields_|.

[xiyuan, 2016/06/10 17:05:59]

Document fieldId?

      */
-    onPasswordChanged_: function(index) {
-      this.maybeSendUpdatedPassword(index);
+    onPasswordChanged_: function(index, fieldId) {
+      this.maybeSendUpdatedPassword(index, fieldId);
     }
   };