Add "previewing on hover" support for password field.

components/autofill/content/renderer/autofill_agent.cc

Index: components/autofill/content/renderer/autofill_agent.cc
diff --git a/components/autofill/content/renderer/autofill_agent.cc b/components/autofill/content/renderer/autofill_agent.cc
index fb58dab42ad8c2c61a6ff867176ec19cedf2a58a..8bd503e300ecba795c11834cb75df09c7da2d737 100644
--- a/components/autofill/content/renderer/autofill_agent.cc
+++ b/components/autofill/content/renderer/autofill_agent.cc
@@ -163,6 +163,8 @@ bool AutofillAgent::OnMessageReceived(const IPC::Message& message) {
                         OnAcceptDataListSuggestion)
     IPC_MESSAGE_HANDLER(AutofillMsg_AcceptPasswordAutofillSuggestion,
                         OnAcceptPasswordAutofillSuggestion)
+    IPC_MESSAGE_HANDLER(AutofillMsg_PreviewPasswordAutofillSuggestion,
+                        OnPreviewPasswordAutofillSuggestion)
     IPC_MESSAGE_HANDLER(AutofillMsg_RequestAutocompleteResult,
                         OnRequestAutocompleteResult)
     IPC_MESSAGE_UNHANDLED(handled = false)
@@ -497,7 +499,17 @@ void AutofillAgent::OnAcceptDataListSuggestion(const base::string16& value) {
 void AutofillAgent::OnAcceptPasswordAutofillSuggestion(
     const base::string16& username,
     const base::string16& password) {
-  bool handled = password_autofill_agent_->AcceptSuggestion(
+  bool handled = password_autofill_agent_->FillSuggestion(
+      element_,
+      username,
+      password);
+  DCHECK(handled);
+}
+
+void AutofillAgent::OnPreviewPasswordAutofillSuggestion(
+    const base::string16& username,
+    const base::string16& password) {
+  bool handled = password_autofill_agent_->PreviewSuggestion(
       element_,
       username,
       password);