Turn IOSFormParser into a static function

IOSFormParser is a class used on iOS to turn a HTML description of
password forms into an internal PasswordForm structure. The class has
no data members and the only method, Parse(), is thus effectively
static.

It was created as a class for two reasons: (1) to allow mocking, and
(2) to enable holding some server-supplied state.

I chatted with dvadym@ and we agreed that once this actually needs
being mocked, we can assess the concrete needs, and perhaps change
some alternative (e.g., providing a fake result for testing) to mocking
which would still require adding a virtual interface and other
boilerplate. Holding the server-supplied state might also likely
end up in PasswordFormManager.

Because it is confusing to create IOSFormParser instances in the
current code and the two concerns above seem addressed, this CL
turns IOSFormParser into a single static function, ParseFormData(),
following the existing pattern found in
components/password_manager/core/browser/import/csv_reader.h.

Bug: 827945
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: Idbbd5087f301bb07974364f7b8bd324ed42a0fa5
Reviewed-on: https://chromium-review.googlesource.com/990333
Commit-Queue: Vaclav Brozek <vabr@chromium.org>
Reviewed-by: Vadym Doroshenko <dvadym@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548740}

components/password_manager/core/browser/form_parsing/ios_form_parser.cc

@@ -307,10 +307,8 @@ void SetFields(const ParseResult& parse_result, PasswordForm* password_form) {
 
 }  // namespace
 
-IOSFormParser::IOSFormParser() = default;
-
-std::unique_ptr<PasswordForm> IOSFormParser::Parse(const FormData& form_data,
-                                                   FormParsingMode mode) {
+std::unique_ptr<PasswordForm> ParseFormData(const FormData& form_data,
+                                            FormParsingMode mode) {
   FieldPointersVector fields = GetNonCreditCardFields(form_data.fields);
 
   // Skip forms without password fields.

components/password_manager/core/browser/form_parsing/ios_form_parser.h

@@ -16,17 +16,12 @@ namespace password_manager {
 
 enum class FormParsingMode { FILLING, SAVING };
 
-class IOSFormParser {
- public:
-  IOSFormParser();
-
-  // Parse DOM information |form_data| to Password Manager form representation
-  // PasswordForm.
-  // Return nullptr when parsing is unsuccessful.
-  std::unique_ptr<autofill::PasswordForm> Parse(
-      const autofill::FormData& form_data,
-      FormParsingMode mode);
-};
+// Parse DOM information |form_data| into Password Manager' form representation
+// PasswordForm.
+// Return nullptr when parsing is unsuccessful.
+std::unique_ptr<autofill::PasswordForm> ParseFormData(
+    const autofill::FormData& form_data,
+    FormParsingMode mode);
 
 }  // namespace password_manager
 

components/password_manager/core/browser/form_parsing/ios_form_parser_unittest.cc

@@ -63,8 +63,6 @@ class IOSFormParserTest : public testing::Test {
   IOSFormParserTest() {}
 
  protected:
-  IOSFormParser form_parser_;
-
   void CheckTestData(const std::vector<FormParsingTestCase>& test_cases);
 };
 
@@ -144,7 +142,7 @@ void IOSFormParserTest::CheckTestData(
           << test_case.description << ", parsing mode = "
           << (mode == FormParsingMode::FILLING ? "Filling" : "Saving"));
       std::unique_ptr<PasswordForm> parsed_form =
-          form_parser_.Parse(form_data, mode);
+          ParseFormData(form_data, mode);
 
       const ParseResultIndices& expected_indices =
           mode == FormParsingMode::FILLING ? test_case.fill_result

ios/chrome/browser/passwords/password_controller.mm

@@ -272,8 +272,6 @@ bool GetPageURLAndCheckTrustLevel(web::WebState* web_state, GURL* page_url) {
 
   AccountSelectFillData fillData_;
 
-  password_manager::IOSFormParser formParser_;
-
   // The WebState this instance is observing. Will be null after
   // -webStateDestroyed: has been called.
   web::WebState* webState_;
@@ -545,7 +543,7 @@ bool GetPageURLAndCheckTrustLevel(web::WebState* web_state, GURL* page_url) {
 
   for (const auto& formData : formsData) {
     std::unique_ptr<PasswordForm> form =
-        formParser_.Parse(formData, password_manager::FormParsingMode::FILLING);
+        ParseFormData(formData, password_manager::FormParsingMode::FILLING);
     if (form)
       forms->push_back(*form);
   }
@@ -582,7 +580,7 @@ bool GetPageURLAndCheckTrustLevel(web::WebState* web_state, GURL* page_url) {
     }
 
     std::unique_ptr<PasswordForm> form =
-        formParser_.Parse(formData, password_manager::FormParsingMode::SAVING);
+        ParseFormData(formData, password_manager::FormParsingMode::SAVING);
     if (!form) {
       completionHandler(NO, PasswordForm());
       return;
@@ -862,7 +860,7 @@ bool GetPageURLAndCheckTrustLevel(web::WebState* web_state, GURL* page_url) {
   }
 
   std::unique_ptr<PasswordForm> form =
-      formParser_.Parse(formData, password_manager::FormParsingMode::SAVING);
+      ParseFormData(formData, password_manager::FormParsingMode::SAVING);
   if (!form)
     return NO;