Add flag to enable/disable affiliaton based matching.

BUG=437865

Review URL: https://codereview.chromium.org/898553002

Cr-Commit-Position: refs/heads/master@{#314545}

chrome/app/generated_resources.grd

@@ -6300,6 +6300,12 @@ Keep your key file in a safe place. You will need it to create new versions of y
       <message name="IDS_FLAGS_ENABLE_SAVE_PASSOWRD_ON_IN_PAGE_NAVIGATION_DESCRIPTION" desc="Description of the flag to enable showing of password save prompt on in-page navigations">
         Enable showing of the password prompt on in-page navigations. This allows for saving passwords on more pages but might sometimes trigger the prompt on unsuccessful login attempts.
       </message>
+      <message name="IDS_FLAGS_ENABLE_AFFILIATION_BASED_MATCHING_NAME" desc="Name of the flag to enable affiliation based matching, so that credentials stored for an Android application will also be considered matches for, and be filled into corresponding websites (so-called 'affiliated' websites).">
+        Enable affiliation based matching in password manager.
+      </message>
+      <message name="IDS_FLAGS_ENABLE_AFFILIATION_BASED_MATCHING_DESCRIPTION" desc="Description of the flag to enable affiliation based matching, so that credentials stored for an Android application will also be considered matches for, and be filled into corresponding websites (so-called 'affiliated' websites).">
+        Allow credentials stored for Android applications to be filled into corresponding websites.
+      </message>
       <message name="IDS_FLAGS_AUTOFILL_SYNC_CREDENTIAL_NAME" desc="Name of the flag specifying how the browser will handle autofilling the users sync credential.">
         Autofill sync credential
       </message>

chrome/browser/about_flags.cc

@@ -1037,6 +1037,15 @@ const Experiment kExperiments[] = {
      SINGLE_VALUE_TYPE(
              autofill::switches::kEnablePasswordSaveOnInPageNavigation)
   },
+  {
+    "enable-affiliation-based-matching",
+    IDS_FLAGS_ENABLE_AFFILIATION_BASED_MATCHING_NAME,
+    IDS_FLAGS_ENABLE_AFFILIATION_BASED_MATCHING_DESCRIPTION,
+    kOsWin | kOsLinux | kOsCrOS | kOsMac | kOsAndroid,
+    ENABLE_DISABLE_VALUE_TYPE(
+        password_manager::switches::kEnableAffiliationBasedMatching,
+        password_manager::switches::kDisableAffiliationBasedMatching)
+  },
   {
     "enable-deferred-image-decoding",
     IDS_FLAGS_ENABLE_DEFERRED_IMAGE_DECODING_NAME,

components/password_manager/core/browser/affiliation_utils.cc

@@ -8,8 +8,11 @@
 #include <ostream>
 
 #include "base/base64.h"
+#include "base/command_line.h"
+#include "base/metrics/field_trial.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/string_util.h"
+#include "components/password_manager/core/common/password_manager_switches.h"
 #include "net/base/escape.h"
 #include "url/third_party/mozilla/url_parse.h"
 #include "url/url_canon_stdstring.h"
@@ -285,4 +288,17 @@ bool AreEquivalenceClassesEqual(const AffiliatedFacets& a,
   return std::equal(a_sorted.begin(), a_sorted.end(), b_sorted.begin());
 }
 
+bool IsAffiliationBasedMatchingEnabled(const base::CommandLine& command_line) {
+  // Note: It is important to always query the field trial state, to ensure that
+  // UMA reports the correct group.
+  const std::string group_name =
+      base::FieldTrialList::FindFullName("AffiliationBasedMatching");
+
+  if (command_line.HasSwitch(switches::kDisableAffiliationBasedMatching))
+    return false;
+  if (command_line.HasSwitch(switches::kEnableAffiliationBasedMatching))
+    return true;
+  return StartsWithASCII(group_name, "Enabled", /*case_sensitive=*/false);
+}
+
 }  // namespace password_manager

components/password_manager/core/browser/affiliation_utils.h

@@ -53,6 +53,10 @@
 #include "base/time/time.h"
 #include "url/url_parse.h"
 
+namespace base {
+class CommandLine;
+}  // namespace base
+
 namespace password_manager {
 
 // Encapsulates a facet URI in canonical form.
@@ -161,6 +165,11 @@ struct AffiliatedFacetsWithUpdateTime {
 bool AreEquivalenceClassesEqual(const AffiliatedFacets& a,
                                 const AffiliatedFacets& b);
 
+// Returns whether or not affiliation based matching is enabled, either via
+// command line flags or field trials. The command line flag, if present, always
+// takes precedence.
+bool IsAffiliationBasedMatchingEnabled(const base::CommandLine& command_line);
+
 // For logging use only.
 std::ostream& operator<<(std::ostream& os, const FacetURI& facet_uri);
 

components/password_manager/core/browser/affiliation_utils_unittest.cc

@@ -4,6 +4,9 @@
 
 #include "components/password_manager/core/browser/affiliation_utils.h"
 
+#include "base/command_line.h"
+#include "base/metrics/field_trial.h"
+#include "components/password_manager/core/common/password_manager_switches.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "url/url_constants.h"
 
@@ -192,4 +195,44 @@ TEST(AffiliationUtilsTest, NotEqualEquivalenceClasses) {
   EXPECT_FALSE(AreEquivalenceClassesEqual(c, b));
 }
 
+TEST(AffiliationUtilsTest, IsAffiliationBasedMatchingEnabled) {
+  const char kFieldTrialName[] = "AffiliationBasedMatching";
+
+  struct {
+    const char* field_trial_group;
+    const char* command_line_switch;
+    bool expected_enabled;
+  } kTestCases[] = {
+      {"", "", false},
+      {"", switches::kEnableAffiliationBasedMatching, true},
+      {"", switches::kDisableAffiliationBasedMatching, false},
+      {"garbage value", "", false},
+      {"disabled", "", false},
+      {"disabled2", "", false},
+      {"Disabled", "", false},
+      {"Disabled", switches::kDisableAffiliationBasedMatching, false},
+      {"Disabled", switches::kEnableAffiliationBasedMatching, true},
+      {"enabled", "", true},
+      {"enabled2", "", true},
+      {"Enabled", "", true},
+      {"Enabled", switches::kDisableAffiliationBasedMatching, false},
+      {"Enabled", switches::kEnableAffiliationBasedMatching, true}};
+
+  for (const auto& test_case : kTestCases) {
+    SCOPED_TRACE(testing::Message("Command line = ")
+                 << test_case.command_line_switch);
+    SCOPED_TRACE(testing::Message("Group name = ")
+                 << test_case.field_trial_group);
+
+    base::FieldTrialList field_trials(NULL);
+    base::FieldTrialList::CreateFieldTrial(kFieldTrialName,
+                                           test_case.field_trial_group);
+
+    base::CommandLine command_line(base::CommandLine::NO_PROGRAM);
+    command_line.AppendSwitch(test_case.command_line_switch);
+    EXPECT_EQ(test_case.expected_enabled,
+              IsAffiliationBasedMatchingEnabled(command_line));
+  }
+}
+
 }  // namespace password_manager

components/password_manager/core/common/password_manager_switches.cc

@@ -11,6 +11,12 @@ namespace switches {
 // Force the password manager to allow sync credentials to be autofilled.
 const char kAllowAutofillSyncCredential[] = "allow-autofill-sync-credential";
 
+// Disable affiliation based matching, so that credentials stored for an Android
+// application will not be considered matches for, and will not be filled into
+// corresponding Web applications.
+const char kDisableAffiliationBasedMatching[] =
+    "disable-affiliation-based-matching";
+
 // Disable dropping the credential used to sync passwords.
 const char kDisableDropSyncCredential[] = "disable-drop-sync-credential";
 
@@ -30,6 +36,12 @@ const char kDisallowAutofillSyncCredential[] =
 const char kDisallowAutofillSyncCredentialForReauth[] =
     "disallow-autofill-sync-credential-for-reauth";
 
+// Enable affiliation based matching, so that credentials stored for an Android
+// application will also be considered matches for, and be filled into
+// corresponding Web applications.
+const char kEnableAffiliationBasedMatching[] =
+    "enable-affiliation-based-matching";
+
 // Disables the save-password prompt. Passwords are then saved automatically,
 // without asking the user.
 const char kEnableAutomaticPasswordSaving[] =

components/password_manager/core/common/password_manager_switches.h

@@ -13,11 +13,13 @@ namespace switches {
 // alongside the definition of their values in the .cc file.
 
 extern const char kAllowAutofillSyncCredential[];
+extern const char kDisableAffiliationBasedMatching[];
 extern const char kDisableDropSyncCredential[];
 extern const char kDisableManagerForSyncSignin[];
 extern const char kDisablePasswordLink[];
 extern const char kDisallowAutofillSyncCredential[];
 extern const char kDisallowAutofillSyncCredentialForReauth[];
+extern const char kEnableAffiliationBasedMatching[];
 extern const char kEnableAutomaticPasswordSaving[];
 extern const char kEnableDropSyncCredential[];
 extern const char kEnableManagerForSyncSignin[];

tools/metrics/histograms/histograms.xml

@@ -50872,6 +50872,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="-158549277" label="enable-embeddedsearch-api"/>
   <int value="-158197254" label="enable-credential-manager-api"/>
   <int value="-147283486" label="enable-network-portal-notification"/>
+  <int value="-146552997" label="enable-affiliation-based-matching"/>
   <int value="-102537270" label="extension-content-verification"/>
   <int value="-99781021" label="disable-roboto-font-ui"/>
   <int value="-88822940" label="ssl-version-min"/>
@@ -50889,6 +50890,7 @@ To add a new entry, add it with any value and run test to compute valid value.
     Command-line flag doesn't start with two dashes.
   </int>
   <int value="27507364" label="apps-keep-chrome-alive"/>
+  <int value="37024318" label="disable-affiliation-based-matching"/>
   <int value="48159177" label="reduced-referrer-granularity"/>
   <int value="61205887" label="enable-text-input-focus-manager"/>
   <int value="79503461" label="disable-account-consistency"/>