Clean up PasswordFormConversionUtilsTest and add some missing tests.

BUG=375333

Review URL: https://codereview.chromium.org/372683003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@282400 0039d316-1c4b-4281-b951-d872f2087c98

components/autofill/content/renderer/password_form_conversion_utils.cc

@@ -22,10 +22,6 @@ using blink::WebVector;
 namespace autofill {
 namespace {
 
-// Maximum number of password fields we will observe before throwing our
-// hands in the air and giving up with a given form.
-static const size_t kMaxPasswords = 3;
-
 // Checks in a case-insensitive way if the autocomplete attribute for the given
 // |element| is present and has the specified |value_in_lowercase|.
 bool HasAutocompleteAttributeValue(const WebInputElement& element,
@@ -132,8 +128,7 @@ void GetPasswordForm(const WebFormElement& form, PasswordForm* password_form) {
     if (!input_element || !input_element->isEnabled())
       continue;
 
-    if ((passwords.size() < kMaxPasswords) &&
-        input_element->isPasswordField()) {
+    if (input_element->isPasswordField()) {
       passwords.push_back(*input_element);
       // If we have not yet considered any element to be the username so far,
       // provisionally select the input element just before the first password

components/autofill/content/renderer/password_form_conversion_utils_browsertest.cc

@@ -9,14 +9,19 @@
 #include "components/autofill/content/renderer/password_form_conversion_utils.h"
 #include "components/autofill/core/common/password_form.h"
 #include "content/public/test/render_view_test.h"
+#include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/WebKit/public/platform/WebVector.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
+#include "third_party/WebKit/public/web/WebFormControlElement.h"
 #include "third_party/WebKit/public/web/WebFormElement.h"
+#include "third_party/WebKit/public/web/WebInputElement.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
 
+using blink::WebFormControlElement;
 using blink::WebFormElement;
 using blink::WebFrame;
+using blink::WebInputElement;
 using blink::WebVector;
 
 namespace autofill {
@@ -65,9 +70,24 @@ class PasswordFormBuilder {
         name_and_id, name_and_id, value, autocomplete_attribute.c_str());
   }
 
-  // Appends a new submit-type field at the end of the form.
-  void AddSubmitButton() {
-    html_ += "<INPUT type=\"submit\" name=\"submit\" value=\"Submit\"/>";
+  // Appends a disabled text-type field at the end of the form.
+  void AddDisabledUsernameField() {
+    html_ += "<INPUT type=\"text\" disabled/>";
+  }
+
+  // Appends a disabled password-type field at the end of the form.
+  void AddDisabledPasswordField() {
+    html_ += "<INPUT type=\"password\" disabled/>";
+  }
+
+  // Appends a new submit-type field at the end of the form with the specified
+  // |name|. If |activated| is true, the test will emulate as if this button
+  // were used to submit the form.
+  void AddSubmitButton(const char* name, bool activated) {
+    base::StringAppendF(
+        &html_,
+        "<INPUT type=\"submit\" name=\"%s\" value=\"Submit\" %s/>",
+        name, activated ? "set-activated-submit" : "");
   }
 
   // Returns the HTML code for the form containing the fields that have been
@@ -103,6 +123,14 @@ class PasswordFormConversionUtilsTest : public content::RenderViewTest {
     frame->document().forms(forms);
     ASSERT_EQ(1U, forms.size());
 
+    WebVector<WebFormControlElement> control_elements;
+    forms[0].getFormControlElements(control_elements);
+    for (size_t i = 0; i < control_elements.size(); ++i) {
+      WebInputElement* input_element = toWebInputElement(&control_elements[i]);
+      if (input_element->hasAttribute("set-activated-submit"))
+        input_element->setActivatedSubmit(true);
+    }
+
     *password_form = CreatePasswordForm(forms[0]);
   }
 
@@ -112,19 +140,22 @@ class PasswordFormConversionUtilsTest : public content::RenderViewTest {
 
 }  // namespace
 
-TEST_F(PasswordFormConversionUtilsTest, ValidWebFormElementToPasswordForm) {
+TEST_F(PasswordFormConversionUtilsTest, BasicFormAttributes) {
   PasswordFormBuilder builder(kTestFormActionURL);
   builder.AddUsernameField("username", "johnsmith", NULL);
-  builder.AddSubmitButton();
+  builder.AddSubmitButton("inactive_submit", false);
+  builder.AddSubmitButton("active_submit", true);
+  builder.AddSubmitButton("inactive_submit2", false);
   builder.AddPasswordField("password", "secret", NULL);
   std::string html = builder.ProduceHTML();
 
   scoped_ptr<PasswordForm> password_form;
   ASSERT_NO_FATAL_FAILURE(LoadHTMLAndConvertForm(html, &password_form));
-  ASSERT_NE(static_cast<PasswordForm*>(NULL), password_form.get());
+  ASSERT_TRUE(password_form);
 
   EXPECT_EQ("data:", password_form->signon_realm);
   EXPECT_EQ(GURL(kTestFormActionURL), password_form->action);
+  EXPECT_EQ(base::UTF8ToUTF16("active_submit"), password_form->submit_element);
   EXPECT_EQ(base::UTF8ToUTF16("username"), password_form->username_element);
   EXPECT_EQ(base::UTF8ToUTF16("johnsmith"), password_form->username_value);
   EXPECT_EQ(base::UTF8ToUTF16("password"), password_form->password_element);
@@ -134,75 +165,28 @@ TEST_F(PasswordFormConversionUtilsTest, ValidWebFormElementToPasswordForm) {
   EXPECT_FALSE(password_form->preferred);
   EXPECT_FALSE(password_form->blacklisted_by_user);
   EXPECT_EQ(PasswordForm::TYPE_MANUAL, password_form->type);
+  EXPECT_FALSE(password_form->use_additional_authentication);
 }
 
-TEST_F(PasswordFormConversionUtilsTest, InvalidWebFormElementToPasswordForm) {
-  PasswordFormBuilder builder("invalid_target");
+TEST_F(PasswordFormConversionUtilsTest, DisabledFieldsAreIgnored) {
+  PasswordFormBuilder builder(kTestFormActionURL);
   builder.AddUsernameField("username", "johnsmith", NULL);
-  builder.AddSubmitButton();
+  builder.AddDisabledUsernameField();
+  builder.AddDisabledPasswordField();
   builder.AddPasswordField("password", "secret", NULL);
+  builder.AddSubmitButton("submit", true);
   std::string html = builder.ProduceHTML();
 
   scoped_ptr<PasswordForm> password_form;
   ASSERT_NO_FATAL_FAILURE(LoadHTMLAndConvertForm(html, &password_form));
-  ASSERT_EQ(static_cast<PasswordForm*>(NULL), password_form.get());
-}
-
-TEST_F(PasswordFormConversionUtilsTest,
-       WebFormWithMultipleUseNameAndPassWordFieldsToPasswordForm) {
-  PasswordFormBuilder builder(kTestFormActionURL);
-  builder.AddUsernameField("username1", "John", NULL);
-  builder.AddPasswordField("password1", "oldsecret", NULL);
-  builder.AddUsernameField("username2", "William", NULL);
-  builder.AddPasswordField("password2", "secret", NULL);
-  builder.AddUsernameField("username3", "Smith", NULL);
-  builder.AddPasswordField("password3", "secret", NULL);
-  builder.AddSubmitButton();
-  std::string html = builder.ProduceHTML();
-
-  scoped_ptr<PasswordForm> password_form;
-  ASSERT_NO_FATAL_FAILURE(LoadHTMLAndConvertForm(html, &password_form));
-  ASSERT_NE(static_cast<PasswordForm*>(NULL), password_form.get());
-
-  EXPECT_EQ("data:", password_form->signon_realm);
-  EXPECT_EQ(GURL(kTestFormActionURL), password_form->action);
-  EXPECT_EQ(base::UTF8ToUTF16("username1"), password_form->username_element);
-  EXPECT_EQ(base::UTF8ToUTF16("John"), password_form->username_value);
-  EXPECT_EQ(base::UTF8ToUTF16("password1"),
-            password_form->password_element);
-  EXPECT_EQ(base::UTF8ToUTF16("oldsecret"), password_form->password_value);
-  EXPECT_EQ(base::UTF8ToUTF16("password2"),
-            password_form->new_password_element);
-  EXPECT_EQ(base::UTF8ToUTF16("secret"), password_form->new_password_value);
-  ASSERT_EQ(2u, password_form->other_possible_usernames.size());
-  EXPECT_EQ(base::UTF8ToUTF16("William"),
-            password_form->other_possible_usernames[0]);
-  EXPECT_EQ(base::UTF8ToUTF16("Smith"),
-            password_form->other_possible_usernames[1]);
-  EXPECT_EQ(PasswordForm::SCHEME_HTML, password_form->scheme);
-  EXPECT_FALSE(password_form->ssl_valid);
-  EXPECT_FALSE(password_form->preferred);
-  EXPECT_FALSE(password_form->blacklisted_by_user);
-  EXPECT_EQ(PasswordForm::TYPE_MANUAL, password_form->type);
-}
-
-TEST_F(PasswordFormConversionUtilsTest,
-       WebFormwithThreeDifferentPasswordsToPasswordForm) {
-  PasswordFormBuilder builder(kTestFormActionURL);
-  builder.AddUsernameField("username1", "John", NULL);
-  builder.AddPasswordField("password1", "alpha", NULL);
-  builder.AddPasswordField("password2", "beta", NULL);
-  builder.AddPasswordField("password3", "gamma", NULL);
-  builder.AddSubmitButton();
-  std::string html = builder.ProduceHTML();
-
-  scoped_ptr<PasswordForm> password_form;
-  ASSERT_NO_FATAL_FAILURE(LoadHTMLAndConvertForm(html, &password_form));
-  ASSERT_EQ(static_cast<PasswordForm*>(NULL), password_form.get());
+  ASSERT_TRUE(password_form);
+  EXPECT_EQ(base::UTF8ToUTF16("username"), password_form->username_element);
+  EXPECT_EQ(base::UTF8ToUTF16("johnsmith"), password_form->username_value);
+  EXPECT_EQ(base::UTF8ToUTF16("password"), password_form->password_element);
+  EXPECT_EQ(base::UTF8ToUTF16("secret"), password_form->password_value);
 }
 
-TEST_F(PasswordFormConversionUtilsTest,
-       UsernameFieldsWithAutocompleteAttributes) {
+TEST_F(PasswordFormConversionUtilsTest, IdentifyingUsernameFields) {
   // Each test case consists of a set of parameters to be plugged into the
   // PasswordFormBuilder below, plus the corresponding expectations.
   struct TestCase {
@@ -211,6 +195,10 @@ TEST_F(PasswordFormConversionUtilsTest,
     const char* expected_username_value;
     const char* expected_other_possible_usernames;
   } cases[] = {
+      // When no elements are marked with autocomplete='username', the text-type
+      // input field before the first password element should get selected as
+      // the username, and the rest should be marked as alternatives.
+      {{NULL, NULL, NULL}, "username2", "William", "John+Smith"},
       // When a sole element is marked with autocomplete='username', it should
       // be treated as the username for sure, with no other_possible_usernames.
       {{"username", NULL, NULL}, "username1", "John", ""},
@@ -232,34 +220,172 @@ TEST_F(PasswordFormConversionUtilsTest,
       {{"USERNAME", NULL, "uSeRNaMe"}, "username1", "John", "Smith"},
       {{"uSeRNaMe", NULL, "USERNAME"}, "username1", "John", "Smith"}};
 
+  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
+    for (size_t nonempty_username_fields = 0; nonempty_username_fields < 2;
+         ++nonempty_username_fields) {
+      SCOPED_TRACE(testing::Message()
+                   << "Iteration " << i << " "
+                   << (nonempty_username_fields ? "nonempty" : "empty"));
+
+      // Repeat each test once with empty, and once with non-empty usernames.
+      // In the former case, no empty other_possible_usernames should be saved.
+      const char* names[3];
+      if (nonempty_username_fields) {
+        names[0] = "John";
+        names[1] = "William";
+        names[2] = "Smith";
+      } else {
+        names[0] = names[1] = names[2] = "";
+      }
+
+      PasswordFormBuilder builder(kTestFormActionURL);
+      builder.AddUsernameField("username1", names[0], cases[i].autocomplete[0]);
+      builder.AddUsernameField("username2", names[1], cases[i].autocomplete[1]);
+      builder.AddPasswordField("password", "secret", NULL);
+      builder.AddUsernameField("username3", names[2], cases[i].autocomplete[2]);
+      builder.AddPasswordField("password2", "othersecret", NULL);
+      builder.AddSubmitButton("submit", true);
+      std::string html = builder.ProduceHTML();
+
+      scoped_ptr<PasswordForm> password_form;
+      ASSERT_NO_FATAL_FAILURE(LoadHTMLAndConvertForm(html, &password_form));
+      ASSERT_TRUE(password_form);
+
+      EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_username_element),
+                password_form->username_element);
+
+      if (nonempty_username_fields) {
+        EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_username_value),
+                  password_form->username_value);
+        EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_other_possible_usernames),
+                  JoinString(password_form->other_possible_usernames, '+'));
+      } else {
+        EXPECT_TRUE(password_form->username_value.empty());
+        EXPECT_TRUE(password_form->other_possible_usernames.empty());
+      }
+
+      // Do a basic sanity check that we are still having a password field.
+      EXPECT_EQ(base::UTF8ToUTF16("password"), password_form->password_element);
+      EXPECT_EQ(base::UTF8ToUTF16("secret"), password_form->password_value);
+    }
+  }
+}
+
+TEST_F(PasswordFormConversionUtilsTest, IdentifyingTwoPasswordFields) {
+  // Each test case consists of a set of parameters to be plugged into the
+  // PasswordFormBuilder below, plus the corresponding expectations.
+  struct TestCase {
+    const char* password_values[2];
+    const char* expected_password_element;
+    const char* expected_password_value;
+    const char* expected_new_password_element;
+    const char* expected_new_password_value;
+  } cases[] = {
+      // Twp non-empty fields with the same value should be treated as a new
+      // password field plus a confirmation field for the new password.
+      {{"alpha", "alpha"}, "", "", "password1", "alpha"},
+      // The same goes if the fields are yet empty: we speculate that we will
+      // identify them as new password fields once they are filled out, and we
+      // want to keep our abstract interpretation of the form less flaky.
+      {{"", ""}, "", "", "password1", ""},
+      // Two different values should be treated as a password change form, one
+      // that also asks for the current password, but only once for the new.
+      {{"alpha", ""}, "password1", "alpha", "password2", ""},
+      {{"", "beta"}, "password1", "", "password2", "beta"},
+      {{"alpha", "beta"}, "password1", "alpha", "password2", "beta"}};
+
+  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
+    SCOPED_TRACE(testing::Message() << "Iteration " << i);
+
+    PasswordFormBuilder builder(kTestFormActionURL);
+    builder.AddPasswordField("password1", cases[i].password_values[0], NULL);
+    builder.AddUsernameField("username1", "William", NULL);
+    builder.AddPasswordField("password2", cases[i].password_values[1], NULL);
+    builder.AddUsernameField("username2", "Smith", NULL);
+    builder.AddSubmitButton("submit", true);
+    std::string html = builder.ProduceHTML();
+
+    scoped_ptr<PasswordForm> password_form;
+    ASSERT_NO_FATAL_FAILURE(LoadHTMLAndConvertForm(html, &password_form));
+    ASSERT_TRUE(password_form);
+
+    EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_password_element),
+              password_form->password_element);
+    EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_password_value),
+              password_form->password_value);
+    EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_new_password_element),
+              password_form->new_password_element);
+    EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_new_password_value),
+              password_form->new_password_value);
+
+    // Do a basic sanity check that we are still selecting the right username.
+    EXPECT_EQ(base::UTF8ToUTF16("username1"), password_form->username_element);
+    EXPECT_EQ(base::UTF8ToUTF16("William"), password_form->username_value);
+    EXPECT_THAT(password_form->other_possible_usernames,
+                testing::ElementsAre(base::UTF8ToUTF16("Smith")));
+  }
+}
+
+TEST_F(PasswordFormConversionUtilsTest, IdentifyingThreePasswordFields) {
+  // Each test case consists of a set of parameters to be plugged into the
+  // PasswordFormBuilder below, plus the corresponding expectations.
+  struct TestCase {
+    const char* password_values[3];
+    const char* expected_password_element;
+    const char* expected_password_value;
+    const char* expected_new_password_element;
+    const char* expected_new_password_value;
+  } cases[] = {
+      // Two fields with the same value, and one different: we should treat this
+      // as a password change form with confirmation for the new password. Note
+      // that we only recognize (current + new + new) and (new + new + current)
+      // without autocomplete attributes.
+      {{"alpha", "", ""}, "password1", "alpha", "password2", ""},
+      {{"", "beta", "beta"}, "password1", "", "password2", "beta"},
+      {{"alpha", "beta", "beta"}, "password1", "alpha", "password2", "beta"},
+      {{"beta", "beta", "alpha"}, "password3", "alpha", "password1", "beta"},
+      // If the fields are yet empty, we speculate that we will identify them as
+      // (current + new + new) once they are filled out, so we should classify
+      // them the same for now to keep our abstract interpretation less flaky.
+      {{"", "", ""}, "password1", "", "password2", ""}};
+      // Note: In all other cases, we give up and consider the form invalid.
+      // This is tested in InvalidFormDueToConfusingPasswordFields.
+
   for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
     SCOPED_TRACE(testing::Message() << "Iteration " << i);
 
     PasswordFormBuilder builder(kTestFormActionURL);
-    builder.AddUsernameField("username1", "John", cases[i].autocomplete[0]);
-    builder.AddUsernameField("username2", "William", cases[i].autocomplete[1]);
-    builder.AddPasswordField("password", "secret", NULL);
-    builder.AddUsernameField("username3", "Smith", cases[i].autocomplete[2]);
-    builder.AddSubmitButton();
+    builder.AddPasswordField("password1", cases[i].password_values[0], NULL);
+    builder.AddUsernameField("username1", "William", NULL);
+    builder.AddPasswordField("password2", cases[i].password_values[1], NULL);
+    builder.AddUsernameField("username2", "Smith", NULL);
+    builder.AddPasswordField("password3", cases[i].password_values[2], NULL);
+    builder.AddSubmitButton("submit", true);
     std::string html = builder.ProduceHTML();
 
     scoped_ptr<PasswordForm> password_form;
     ASSERT_NO_FATAL_FAILURE(LoadHTMLAndConvertForm(html, &password_form));
-    ASSERT_NE(static_cast<PasswordForm*>(NULL), password_form.get());
-
-    EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_username_element),
-              password_form->username_element);
-    EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_username_value),
-              password_form->username_value);
-    EXPECT_EQ(base::UTF8ToUTF16("password"), password_form->password_element);
-    EXPECT_EQ(base::UTF8ToUTF16("secret"), password_form->password_value);
-    EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_other_possible_usernames),
-              JoinString(password_form->other_possible_usernames, '+'));
+    ASSERT_TRUE(password_form);
+
+    EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_password_element),
+              password_form->password_element);
+    EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_password_value),
+              password_form->password_value);
+    EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_new_password_element),
+              password_form->new_password_element);
+    EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_new_password_value),
+              password_form->new_password_value);
+
+    // Do a basic sanity check that we are still selecting the right username.
+    EXPECT_EQ(base::UTF8ToUTF16("username1"), password_form->username_element);
+    EXPECT_EQ(base::UTF8ToUTF16("William"), password_form->username_value);
+    EXPECT_THAT(password_form->other_possible_usernames,
+                testing::ElementsAre(base::UTF8ToUTF16("Smith")));
   }
 }
 
 TEST_F(PasswordFormConversionUtilsTest,
-       PasswordFieldsWithAutocompleteAttributes) {
+       IdentifyingPasswordFieldsWithAutocompleteAttributes) {
   // Each test case consists of a set of parameters to be plugged into the
   // PasswordFormBuilder below, plus the corresponding expectations.
   struct TestCase {
@@ -361,23 +487,27 @@ TEST_F(PasswordFormConversionUtilsTest,
     SCOPED_TRACE(testing::Message() << "Iteration " << i);
 
     PasswordFormBuilder builder(kTestFormActionURL);
+    builder.AddPasswordField("pin1", "123456", NULL);
+    builder.AddPasswordField("pin2", "789101", NULL);
     builder.AddPasswordField("password1", "alpha", cases[i].autocomplete[0]);
     builder.AddUsernameField("username1", "William", NULL);
     builder.AddPasswordField("password2", "beta", cases[i].autocomplete[1]);
     builder.AddUsernameField("username2", "Smith", NULL);
     builder.AddPasswordField("password3", "gamma", cases[i].autocomplete[2]);
-    builder.AddSubmitButton();
+    builder.AddSubmitButton("submit", true);
     std::string html = builder.ProduceHTML();
 
     scoped_ptr<PasswordForm> password_form;
     ASSERT_NO_FATAL_FAILURE(LoadHTMLAndConvertForm(html, &password_form));
-    ASSERT_NE(static_cast<PasswordForm*>(NULL), password_form.get());
+    ASSERT_TRUE(password_form);
 
-    // Any constellation of password autocomplete attributes should have no
-    // effect on that the first text-type input field before a password field
-    // should be selected as the username.
+    // In the absence of username autocomplete attributes, the username should
+    // be the text input field before the first password element.
+    // No constellation of password autocomplete attributes should change that.
     EXPECT_EQ(base::UTF8ToUTF16("username1"), password_form->username_element);
     EXPECT_EQ(base::UTF8ToUTF16("William"), password_form->username_value);
+    EXPECT_THAT(password_form->other_possible_usernames,
+                testing::ElementsAre(base::UTF8ToUTF16("Smith")));
     EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_password_element),
               password_form->password_element);
     EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_password_value),
@@ -386,10 +516,78 @@ TEST_F(PasswordFormConversionUtilsTest,
               password_form->new_password_element);
     EXPECT_EQ(base::UTF8ToUTF16(cases[i].expected_new_password_value),
               password_form->new_password_value);
-    ASSERT_EQ(1u, password_form->other_possible_usernames.size());
-    EXPECT_EQ(base::UTF8ToUTF16("Smith"),
-              password_form->other_possible_usernames[0]);
   }
 }
 
+TEST_F(PasswordFormConversionUtilsTest, InvalidFormDueToBadActionURL) {
+  PasswordFormBuilder builder("invalid_target");
+  builder.AddUsernameField("username", "JohnSmith", NULL);
+  builder.AddSubmitButton("submit", true);
+  builder.AddPasswordField("password", "secret", NULL);
+  std::string html = builder.ProduceHTML();
+
+  scoped_ptr<PasswordForm> password_form;
+  ASSERT_NO_FATAL_FAILURE(LoadHTMLAndConvertForm(html, &password_form));
+  EXPECT_FALSE(password_form);
+}
+
+TEST_F(PasswordFormConversionUtilsTest, InvalidFormDueToNoPasswordFields) {
+  PasswordFormBuilder builder(kTestFormActionURL);
+  builder.AddUsernameField("username1", "John", NULL);
+  builder.AddUsernameField("username2", "Smith", NULL);
+  builder.AddSubmitButton("submit", true);
+  std::string html = builder.ProduceHTML();
+
+  scoped_ptr<PasswordForm> password_form;
+  ASSERT_NO_FATAL_FAILURE(LoadHTMLAndConvertForm(html, &password_form));
+  EXPECT_FALSE(password_form);
+}
+
+TEST_F(PasswordFormConversionUtilsTest,
+       InvalidFormsDueToConfusingPasswordFields) {
+  // Each test case consists of a set of parameters to be plugged into the
+  // PasswordFormBuilder below.
+  const char* cases[][3] = {
+      // No autocomplete attributes to guide us, and we see:
+      //  * three password values that are all different,
+      //  * three password values that are all the same;
+      //  * three password values with the first and last matching.
+      // In any case, we should just give up on this form.
+      {"alpha", "beta", "gamma"},
+      {"alpha", "alpha", "alpha"},
+      {"alpha", "beta", "alpha"}};
+
+  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
+    SCOPED_TRACE(testing::Message() << "Iteration " << i);
+
+    PasswordFormBuilder builder(kTestFormActionURL);
+    builder.AddUsernameField("username1", "John", NULL);
+    builder.AddPasswordField("password1", cases[i][0], NULL);
+    builder.AddPasswordField("password2", cases[i][1], NULL);
+    builder.AddPasswordField("password3", cases[i][2], NULL);
+    builder.AddSubmitButton("submit", true);
+    std::string html = builder.ProduceHTML();
+
+    scoped_ptr<PasswordForm> password_form;
+    ASSERT_NO_FATAL_FAILURE(LoadHTMLAndConvertForm(html, &password_form));
+    EXPECT_FALSE(password_form);
+  }
+}
+
+TEST_F(PasswordFormConversionUtilsTest,
+       InvalidFormDueToTooManyPasswordFieldsWithoutAutocompleteAttributes) {
+  PasswordFormBuilder builder(kTestFormActionURL);
+  builder.AddUsernameField("username1", "John", NULL);
+  builder.AddPasswordField("password1", "alpha", NULL);
+  builder.AddPasswordField("password2", "alpha", NULL);
+  builder.AddPasswordField("password3", "alpha", NULL);
+  builder.AddPasswordField("password4", "alpha", NULL);
+  builder.AddSubmitButton("submit", true);
+  std::string html = builder.ProduceHTML();
+
+  scoped_ptr<PasswordForm> password_form;
+  ASSERT_NO_FATAL_FAILURE(LoadHTMLAndConvertForm(html, &password_form));
+  EXPECT_FALSE(password_form);
+}
+
 }  // namespace autofill