Fill on account select in the password manager

components/autofill/content/renderer/password_autofill_agent.cc

Index: components/autofill/content/renderer/password_autofill_agent.cc
diff --git a/components/autofill/content/renderer/password_autofill_agent.cc b/components/autofill/content/renderer/password_autofill_agent.cc
index 7a9099b6aabc2e2115724c67eaa1a98b7a4542bc..93685a7b432b5fad1545c4bc1dab634a79c8345c 100644
--- a/components/autofill/content/renderer/password_autofill_agent.cc
+++ b/components/autofill/content/renderer/password_autofill_agent.cc
@@ -5,6 +5,7 @@
 #include "components/autofill/content/renderer/password_autofill_agent.h"
 
 #include "base/bind.h"
+#include "base/command_line.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
@@ -13,6 +14,7 @@
 #include "components/autofill/content/renderer/form_autofill_util.h"
 #include "components/autofill/content/renderer/password_form_conversion_utils.h"
 #include "components/autofill/content/renderer/renderer_save_password_progress_logger.h"
+#include "components/autofill/core/common/autofill_switches.h"
 #include "components/autofill/core/common/form_field_data.h"
 #include "components/autofill/core/common/password_form.h"
 #include "components/autofill/core/common/password_form_fill_data.h"
@@ -119,6 +121,23 @@ bool FindFormInputElement(blink::WebFormElement* form_element,
   return true;
 }
 
+bool ShouldFillOnAccountSelect() {
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableFillOnAccountSelect)) {
+    return true;
+  }
+
+  // This is made explicit in anticiption of experimental groups being added.
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDisableFillOnAccountSelect)) {
+    return false;
+  }
+
+  // TODO(jww): Add experimental groups check here.
+
+  return false;
+}
+
 // Helper to search the given form element for the specified input elements in
 // |data|, and add results to |result|.
 bool FindFormInputElements(blink::WebFormElement* form_element,
@@ -280,7 +299,8 @@ bool GetSuggestionsStats(const PasswordFormFillData& fill_data,
 // with values from |fill_data|. The |password_element| will only have the
 // |suggestedValue| set, and will be registered for copying that to the real
 // value through |registration_callback|. The function returns true when
-// selected username comes from |fill_data.other_possible_usernames|.
+// selected username comes from |fill_data.other_possible_usernames|. |options|
+// should be a bitwise mask of FillUserNameAndPasswordOptions values.
 bool FillUserNameAndPassword(
     blink::WebInputElement* username_element,
     blink::WebInputElement* password_element,
@@ -381,7 +401,7 @@ bool FillUserNameAndPassword(
 // |suggestedValue| set, and |suggestedValue| will be registered for copying to
 // the real value through |registration_callback|. Returns true when the
 // username gets selected from |other_possible_usernames|, else returns false.
-bool FillFormOnPasswordRecieved(
+bool FillFormOnPasswordReceived(
     const PasswordFormFillData& fill_data,
     blink::WebInputElement username_element,
     blink::WebInputElement password_element,
@@ -396,13 +416,34 @@ bool FillFormOnPasswordRecieved(
     return false;
 
   bool form_contains_username_field = FillDataContainsUsername(fill_data);
-  // Try to set the username to the preferred name, but only if the field
-  // can be set and isn't prefilled.
-  if (form_contains_username_field &&
-      IsElementAutocompletable(username_element) &&
-      username_element.value().isEmpty()) {
-    // TODO(tkent): Check maxlength and pattern.
-    username_element.setValue(fill_data.username_field.value, true);
+  // If the form contains a username field, try to set the username to the
+  // preferred name, but only if:
+  //   (a) The username element is autocompletable, and
+  //   (b) The fill-on-account-select flag is not set, and
+  //   (c) The username element isn't prefilled
+  //
+  // If (a) is true but (b) is false, then just mark the username element as
+  // autofilled and return so the fill step is skipped.
+  //
+  // If (a) is false but (b) is true, then the username element should not be
+  // autofilled, but the user should still be able to select to fill the
+  // password element, so the password element must be marked as autofilled and
+  // the fill step should also be skipped.
+  //
+  // In all other cases, do nothing.
+  if (form_contains_username_field) {
+    if (IsElementAutocompletable(username_element)) {
+      if (ShouldFillOnAccountSelect()) {
+        username_element.setAutofilled(true);
+        return false;
+      } else if (username_element.value().isEmpty()) {
+        // TODO(tkent): Check maxlength and pattern.
+        username_element.setValue(fill_data.username_field.value, true);
+      }
+    } else if (ShouldFillOnAccountSelect()) {
+      password_element.setAutofilled(true);
+      return false;
+    }
   }
 
   // Fill if we have an exact match for the username. Note that this sets
@@ -514,11 +555,7 @@ bool PasswordAutofillAgent::TextFieldDidEndEditing(
   // Do not set selection when ending an editing session, otherwise it can
   // mess with focus.
   if (FillUserNameAndPassword(
-          &username,
-          &password,
-          fill_data,
-          true /* exact_username_match */,
-          false /* set_selection */,
+          &username, &password, fill_data, true, false,
           base::Bind(&PasswordValueGatekeeper::RegisterElement,
                      base::Unretained(&gatekeeper_)))) {
     usernames_usage_ = OTHER_POSSIBLE_USERNAME_SELECTED;
@@ -581,7 +618,7 @@ bool PasswordAutofillAgent::TextDidChangeInTextField(
   // But refresh the popup.  Note, since this is ours, return true to signal
   // no further processing is required.
   if (iter->second.backspace_pressed_last) {
-    ShowSuggestionPopup(iter->second.fill_data, element, false);
+    ShowSuggestionPopup(iter->second.fill_data, element, false, false);
     return true;
   }
 
@@ -678,11 +715,28 @@ bool PasswordAutofillAgent::DidClearAutofillSelection(
   return true;
 }
 
+PasswordAutofillAgent::LoginToPasswordInfoMap::iterator
+PasswordAutofillAgent::FindPasswordInfoForElement(
+    const blink::WebInputElement& element) {
+  const blink::WebInputElement* username_element;
+  if (!element.isPasswordField()) {
+    username_element = &element;
+  } else {
+    PasswordToLoginMap::const_iterator password_iter =
+        password_to_username_.find(element);
+    if (password_iter == password_to_username_.end())
+      return login_to_password_info_.end();
+    username_element = &password_iter->second;
+  }
+
+  return login_to_password_info_.find(*username_element);
+}
+
 bool PasswordAutofillAgent::ShowSuggestions(
     const blink::WebInputElement& element,
     bool show_all) {
   LoginToPasswordInfoMap::const_iterator iter =
-      login_to_password_info_.find(element);
+      FindPasswordInfoForElement(element);
   if (iter == login_to_password_info_.end())
     return false;
 
@@ -694,7 +748,13 @@ bool PasswordAutofillAgent::ShowSuggestions(
       !IsElementAutocompletable(iter->second.password_field))
     return true;
 
-  return ShowSuggestionPopup(iter->second.fill_data, element, show_all);
+  // Chrome should never show more than one account for a password element since
+  // this implies that the username element cannot be modified. Thus even if
+  // |show_all| is true, check if the element in question is a password element
+  // for the call to ShowSuggestionPopup.
+  return ShowSuggestionPopup(iter->second.fill_data, iter->first,
+                             show_all && !element.isPasswordField(),
+                             element.isPasswordField());
 }
 
 bool PasswordAutofillAgent::OriginCanAccessPasswordManager(
@@ -1042,10 +1102,8 @@ void PasswordAutofillAgent::OnFillPasswordForm(
     // If wait_for_username is true, we don't want to initially fill the form
     // until the user types in a valid username.
     if (!form_data.wait_for_username &&
-        FillFormOnPasswordRecieved(
-            form_data,
-            username_element,
-            password_element,
+        FillFormOnPasswordReceived(
+            form_data, username_element, password_element,
             base::Bind(&PasswordValueGatekeeper::RegisterElement,
                        base::Unretained(&gatekeeper_)))) {
       usernames_usage_ = OTHER_POSSIBLE_USERNAME_SELECTED;
@@ -1079,7 +1137,8 @@ PasswordAutofillAgent::PasswordInfo::PasswordInfo()
 bool PasswordAutofillAgent::ShowSuggestionPopup(
     const PasswordFormFillData& fill_data,
     const blink::WebInputElement& user_input,
-    bool show_all) {
+    bool show_all,
+    bool show_on_password_field) {
   blink::WebFrame* frame = user_input.document().frame();
   if (!frame)
     return false;
@@ -1094,6 +1153,12 @@ bool PasswordAutofillAgent::ShowSuggestionPopup(
       user_input, &form, &field, REQUIRE_NONE);
 
   blink::WebInputElement selected_element = user_input;
+  if (show_on_password_field) {
+    LoginToPasswordInfoMap::const_iterator iter =
+        login_to_password_info_.find(user_input);
+    DCHECK(iter != login_to_password_info_.end());
+    selected_element = iter->second.password_field;
+  }
   gfx::Rect bounding_box(selected_element.boundsInViewportSpace());
 
   LoginToPasswordInfoKeyMap::const_iterator key_it =
@@ -1105,9 +1170,14 @@ bool PasswordAutofillAgent::ShowSuggestionPopup(
                                  bounding_box.y() * scale,
                                  bounding_box.width() * scale,
                                  bounding_box.height() * scale);
+  int options = 0;
+  if (show_all)
+    options |= ShowPasswordSuggestionsOptions::SHOW_ALL;
+  if (show_on_password_field)
+    options |= ShowPasswordSuggestionsOptions::IS_PASSWORD_FIELD;
   Send(new AutofillHostMsg_ShowPasswordSuggestions(
       routing_id(), key_it->second, field.text_direction, user_input.value(),
-      show_all, bounding_box_scaled));
+      options, bounding_box_scaled));
 
   bool suggestions_present = false;
   if (GetSuggestionsStats(fill_data, user_input.value(), show_all,
@@ -1135,17 +1205,13 @@ void PasswordAutofillAgent::PerformInlineAutocomplete(
   }
 
   // Show the popup with the list of available usernames.
-  ShowSuggestionPopup(fill_data, username, false);
+  ShowSuggestionPopup(fill_data, username, false, false);
 
 #if !defined(OS_ANDROID)
   // Fill the user and password field with the most relevant match. Android
   // only fills in the fields after the user clicks on the suggestion popup.
   if (FillUserNameAndPassword(
-          &username,
-          &password,
-          fill_data,
-          false /* exact_username_match */,
-          true /* set_selection */,
+          &username, &password, fill_data, false, true,
           base::Bind(&PasswordValueGatekeeper::RegisterElement,
                      base::Unretained(&gatekeeper_)))) {
     usernames_usage_ = OTHER_POSSIBLE_USERNAME_SELECTED;
@@ -1187,7 +1253,7 @@ bool PasswordAutofillAgent::FindLoginInfo(const blink::WebNode& node,
     return false;
 
   blink::WebInputElement input = element.to<blink::WebInputElement>();
-  LoginToPasswordInfoMap::iterator iter = login_to_password_info_.find(input);
+  LoginToPasswordInfoMap::iterator iter = FindPasswordInfoForElement(input);
   if (iter == login_to_password_info_.end())
     return false;