Password autofill should not override explicitly typed password

chrome/renderer/autofill/password_autofill_agent_browsertest.cc

Index: chrome/renderer/autofill/password_autofill_agent_browsertest.cc
diff --git a/chrome/renderer/autofill/password_autofill_agent_browsertest.cc b/chrome/renderer/autofill/password_autofill_agent_browsertest.cc
index d228ca28a520424f16080e9e205491e365aacd16..8433372b05a8acc068f6989f1ede0d497f3d0064 100644
--- a/chrome/renderer/autofill/password_autofill_agent_browsertest.cc
+++ b/chrome/renderer/autofill/password_autofill_agent_browsertest.cc
@@ -261,21 +261,26 @@ class PasswordAutofillAgentTest : public ChromeRenderViewTest {
     password_element_.setAutofilled(false);
   }
 
-  void SimulateUsernameChangeForElement(const std::string& username,
-                                        bool move_caret_to_end,
-                                        WebFrame* input_frame,
-                                        WebInputElement& username_input,
-                                        bool is_user_input) {
-    username_input.setValue(WebString::fromUTF8(username), is_user_input);
+  void SimulateDidEndEditingWithNoChangeForElement(WebFrame* input_frame,
+                                                   WebInputElement& input) {
+    autofill_agent_->textFieldDidEndEditing(input);
+  }
+
+  void SimulateInputChangeForElement(const std::string& new_value,
+                                     bool move_caret_to_end,
+                                     WebFrame* input_frame,
+                                     WebInputElement& input,
+                                     bool is_user_input) {
+    input.setValue(WebString::fromUTF8(new_value), is_user_input);
     // The field must have focus or AutofillAgent will think the
     // change should be ignored.
-    while (!username_input.focused())
+    while (!input.focused())
       input_frame->document().frame()->view()->advanceFocus(false);
     if (move_caret_to_end)
-      username_input.setSelectionRange(username.length(), username.length());
+      input.setSelectionRange(new_value.length(), new_value.length());
     if (is_user_input)
-      autofill_agent_->password_autofill_agent_->gatekeeper_.OnUserGesture();
-    autofill_agent_->textFieldDidChange(username_input);
+      autofill_agent_->password_autofill_agent_->FirstUserGestureObserved();
+    autofill_agent_->textFieldDidChange(input);
     // Processing is delayed because of a Blink bug:
     // https://bugs.webkit.org/show_bug.cgi?id=16976
     // See PasswordAutofillAgent::TextDidChangeInTextField() for details.
@@ -310,11 +315,11 @@ class PasswordAutofillAgentTest : public ChromeRenderViewTest {
   void SimulateUsernameChange(const std::string& username,
                               bool move_caret_to_end,
                               bool is_user_input = false) {
-    SimulateUsernameChangeForElement(username,
-                                     move_caret_to_end,
-                                     GetMainFrame(),
-                                     username_element_,
-                                     is_user_input);
+    SimulateInputChangeForElement(username,
+                                  move_caret_to_end,
+                                  GetMainFrame(),
+                                  username_element_,
+                                  is_user_input);
   }
 
   // Tests that no suggestion popup is generated when the username_element_ is
@@ -904,7 +909,7 @@ TEST_F(PasswordAutofillAgentTest, IframeNoFillTest) {
 
   // Simulate the user typing in the username in the iframe which should cause
   // an autofill.
-  SimulateUsernameChangeForElement(
+  SimulateInputChangeForElement(
       kAliceUsername, true, iframe, username_input, true);
 
   CheckTextFieldsStateForElements(username_input,
@@ -1474,4 +1479,42 @@ TEST_F(PasswordAutofillAgentTest, CredentialsOnClick) {
   ExpectAllCredentials();
 }
 
+// The user first accepts a suggestion, but then overwrites the password. This
+// test checks that the overwritten password is not reverted back by the user
+// triggering autofill through focusing (but not changing) the username again.
+TEST_F(PasswordAutofillAgentTest, PasswordNotOverwritten) {
+  // Simulate having credentials which needed to wait until the user starts
+  // typing the username to be filled (e.g., PSL-matched credentials). Those are
+  // the ones which can be filled as a result of TextFieldDidEndEditing.
+  fill_data_.wait_for_username = true;
+  // Simulate that the user typed her name to make the autofill work.
+  SimulateInputChangeForElement(kAliceUsername,
+                                /*move_caret_to_end=*/true,
+                                GetMainFrame(),
+                                username_element_,
+                                /*is_user_input=*/true);
+  SimulateOnFillPasswordForm(fill_data_);
+
+  const std::string old_username(username_element_.value().utf8());
+  const std::string old_password(password_element_.value().utf8());
+  const std::string new_password(old_password + "modify");
+
+  // The user changes the password.
+  SimulateInputChangeForElement(new_password,
+                                /*move_caret_to_end=*/true,
+                                GetMainFrame(),
+                                password_element_,
+                                /*is_user_input=*/true);
+
+  // The user switches back into the username field, but leaves that without
+  // changes.
+  SimulateDidEndEditingWithNoChangeForElement(GetMainFrame(),
+                                              username_element_);
+
+  // The password should have stayed as the user changed it.
+  CheckTextFieldsDOMState(old_username, false, new_password, false);
+  // The password should not have a suggested value.
+  CheckTextFieldsState(old_username, false, std::string(), false);
+}
+
 }  // namespace autofill