Fix export reset when completionWithItemsHandler is not called

Re-enable password export when the activity view disappears, instead of when completionWithItemsHandler is called. This has the potential to be a premature re-enabling, if the user decides to background the app launched from the activity view and come back to Chrome’s password settings. Re-triggering the export in this case might cause a conflict between multiple exported files.

To mitigate this issue, each exported file is stored in its own uniquely identified folder in tmp/passwords/. If completionWithItemsHandler is called, the file and its folder are removed. For the cases in which the completion handler is not called, the rest of the files are deleted at startup.


Bug: 820053
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I5683acfe8483876c0aeb81ce25ba83b24f109676
Reviewed-on: https://chromium-review.googlesource.com/974181
Commit-Queue: Ioana Pandele <ioanap@chromium.org>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#546148}

ios/chrome/app/BUILD.gn

@@ -139,6 +139,7 @@ source_set("app_internal") {
     "//components/keyed_service/ios",
     "//components/metrics",
     "//components/ntp_snippets",
+    "//components/password_manager/core/common",
     "//components/payments/core",
     "//components/prefs",
     "//components/proxy_config",
@@ -175,6 +176,7 @@ source_set("app_internal") {
     "//ios/chrome/browser/net",
     "//ios/chrome/browser/ntp_snippets",
     "//ios/chrome/browser/omaha",
+    "//ios/chrome/browser/passwords",
     "//ios/chrome/browser/payments",
     "//ios/chrome/browser/payments:constants",
     "//ios/chrome/browser/prefs",

ios/chrome/app/DEPS

@@ -13,6 +13,7 @@ include_rules = [
   "+components/history/core/browser",
   "+components/metrics",
   "+components/ntp_snippets",
+  "+components/password_manager/core/common",
   "+components/payments/core",
   "+components/prefs",
   "+components/reading_list/core",

ios/chrome/app/main_controller.mm

@@ -33,6 +33,7 @@
 #include "components/metrics/metrics_pref_names.h"
 #include "components/metrics/metrics_service.h"
 #include "components/ntp_snippets/content_suggestions_service.h"
+#include "components/password_manager/core/common/password_manager_features.h"
 #include "components/payments/core/features.h"
 #include "components/prefs/pref_change_registrar.h"
 #include "components/signin/core/browser/signin_manager.h"
@@ -86,6 +87,7 @@
 #import "ios/chrome/browser/metrics/previous_session_info.h"
 #import "ios/chrome/browser/net/cookie_util.h"
 #include "ios/chrome/browser/ntp_snippets/ios_chrome_content_suggestions_service_factory.h"
+#import "ios/chrome/browser/passwords/passwords_directory_util.h"
 #include "ios/chrome/browser/payments/ios_payment_instrument_launcher.h"
 #include "ios/chrome/browser/payments/ios_payment_instrument_launcher_factory.h"
 #import "ios/chrome/browser/payments/payment_request_constants.h"
@@ -197,6 +199,9 @@ NSString* const kCheckForFirstPartyApps = @"CheckForFirstPartyApps";
 // Constants for deferred deletion of leftover user downloaded files.
 NSString* const kDeleteDownloads = @"DeleteDownloads";
 
+// Constants for deferred deletion of leftover temporary passwords files.
+NSString* const kDeleteTempPasswords = @"DeleteTempPasswords";
+
 // Constants for deferred sending of queued feedback.
 NSString* const kSendQueuedFeedback = @"SendQueuedFeedback";
 
@@ -502,6 +507,9 @@ void MainControllerAuthenticationServiceDelegate::ClearBrowsingData(
 // Schedules the deletion of user downloaded files that might be leftover
 // from the last time Chrome was run.
 - (void)scheduleDeleteDownloadsDirectory;
+// Schedule the deletion of the temporary passwords files that might
+// be left over from incomplete export operations.
+- (void)scheduleDeleteTempPasswordsDirectory;
 // Returns whether or not the app can launch in incognito mode.
 - (BOOL)canLaunchInIncognito;
 // Determines which UI should be shown on startup, and shows it.
@@ -1150,6 +1158,10 @@ void MainControllerAuthenticationServiceDelegate::ClearBrowsingData(
   [self sendQueuedFeedback];
   [self scheduleSpotlightResync];
   [self scheduleDeleteDownloadsDirectory];
+  if (base::FeatureList::IsEnabled(
+          password_manager::features::kPasswordExport)) {
+    [self scheduleDeleteTempPasswordsDirectory];
+  }
   [self scheduleStartupAttemptReset];
   [self startFreeMemoryMonitoring];
   [self scheduleAppDistributionPings];
@@ -1177,6 +1189,14 @@ void MainControllerAuthenticationServiceDelegate::ClearBrowsingData(
                   }];
 }
 
+- (void)scheduleDeleteTempPasswordsDirectory {
+  [[DeferredInitializationRunner sharedInstance]
+      enqueueBlockNamed:kDeleteTempPasswords
+                  block:^{
+                    DeletePasswordsDirectory();
+                  }];
+}
+
 - (void)scheduleSpotlightResync {
   if (!_spotlightManager) {
     return;

ios/chrome/browser/passwords/BUILD.gn

@@ -42,6 +42,8 @@ source_set("passwords") {
     "password_manager_internals_service_factory.h",
     "password_tab_helper.h",
     "password_tab_helper.mm",
+    "passwords_directory_util.h",
+    "passwords_directory_util.mm",
     "update_password_infobar_controller.h",
     "update_password_infobar_controller.mm",
   ]
@@ -122,6 +124,7 @@ source_set("unit_tests") {
     "js_credential_manager_unittest.mm",
     "password_controller_js_unittest.mm",
     "password_controller_unittest.mm",
+    "passwords_directory_util_unittest.mm",
     "test_helpers.cc",
     "test_helpers.h",
   ]

ios/chrome/browser/passwords/passwords_directory_util.h

+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_CHROME_BROWSER_PASSWORDS_PASSWORDS_DIRECTORY_UTIL_H_
+#define IOS_CHROME_BROWSER_PASSWORDS_PASSWORDS_DIRECTORY_UTIL_H_
+
+#import <Foundation/Foundation.h>
+
+// Returns the URL to the passwords directory.
+NSURL* GetPasswordsDirectoryURL();
+
+// Asynchronously deletes the temporary passwords directory.
+void DeletePasswordsDirectory();
+
+#endif  // IOS_CHROME_BROWSER_PASSWORDS_PASSWORDS_DIRECTORY_UTIL_H_

ios/chrome/browser/passwords/passwords_directory_util.mm

+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "ios/chrome/browser/passwords/passwords_directory_util.h"
+
+#include "base/task_scheduler/post_task.h"
+#include "base/threading/thread_restrictions.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+namespace {
+// Synchronously deletes passwords directoy.
+void DeletePasswordsDirectorySync() {
+  NSFileManager* file_manager = [NSFileManager defaultManager];
+  base::AssertBlockingAllowed();
+  NSURL* passwords_directory = GetPasswordsDirectoryURL();
+  [file_manager removeItemAtURL:passwords_directory error:nil];
+}
+}  // namespace
+
+NSURL* GetPasswordsDirectoryURL() {
+  return [[NSURL fileURLWithPath:NSTemporaryDirectory() isDirectory:YES]
+      URLByAppendingPathComponent:@"passwords"
+                      isDirectory:YES];
+}
+
+void DeletePasswordsDirectory() {
+  base::PostTaskWithTraits(FROM_HERE,
+                           {base::MayBlock(), base::TaskPriority::BACKGROUND},
+                           base::BindOnce(&DeletePasswordsDirectorySync));
+}

ios/chrome/browser/passwords/passwords_directory_util_unittest.mm

+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ios/chrome/browser/passwords/passwords_directory_util.h"
+
+#include "base/mac/bind_objc_block.h"
+#include "base/task_scheduler/post_task.h"
+#include "base/test/scoped_task_environment.h"
+#import "ios/testing/wait_util.h"
+#include "testing/platform_test.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+using testing::WaitUntilConditionOrTimeout;
+using testing::kWaitForFileOperationTimeout;
+
+using PasswordsDirectoryUtilTest = PlatformTest;
+
+// Tests that DeletePasswordsDirectory() actually deletes the directory.
+TEST_F(PasswordsDirectoryUtilTest, Deletion) {
+  base::test::ScopedTaskEnvironment environment;
+
+  NSURL* directory_url = GetPasswordsDirectoryURL();
+  NSURL* file_url =
+      [directory_url URLByAppendingPathComponent:@"TestPasswords.csv"];
+
+  // Create a new file in the passwords  directory.
+  base::PostTaskWithTraits(
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::USER_BLOCKING},
+      base::BindBlockArc(^() {
+        NSFileManager* file_manager = [NSFileManager defaultManager];
+        if ([file_manager createDirectoryAtURL:directory_url
+                   withIntermediateDirectories:NO
+                                    attributes:nil
+                                         error:nil]) {
+          [@"test" writeToURL:file_url
+                   atomically:YES
+                     encoding:NSUTF8StringEncoding
+                        error:nil];
+        }
+      }));
+
+  // Verify that the file was created in the passwords directory.
+  EXPECT_TRUE(
+      WaitUntilConditionOrTimeout(kWaitForFileOperationTimeout, ^bool() {
+        return [[NSFileManager defaultManager] fileExistsAtPath:file_url.path];
+      }));
+
+  // Delete download directory.
+  DeletePasswordsDirectory();
+
+  // Verify passwords directory deletion.
+  EXPECT_TRUE(
+      WaitUntilConditionOrTimeout(kWaitForFileOperationTimeout, ^bool() {
+        return ![[NSFileManager defaultManager] fileExistsAtPath:file_url.path];
+      }));
+}

ios/chrome/browser/ui/settings/BUILD.gn

@@ -363,6 +363,7 @@ source_set("eg_tests") {
     "//ios/chrome/browser/signin",
     "//ios/chrome/browser/sync",
     "//ios/chrome/browser/ui:ui_internal",
+    "//ios/chrome/browser/ui:ui_util",
     "//ios/chrome/browser/ui/authentication:authentication_ui",
     "//ios/chrome/browser/ui/authentication:eg_test_support",
     "//ios/chrome/browser/ui/settings:test_support",

ios/chrome/browser/ui/settings/password_exporter.h

@@ -96,6 +96,9 @@ enum class ExportState {
 // Called when the user cancels the export operation.
 - (void)cancelExport;
 
+// Called to re-enable export functionality when the export UI flow finishes.
+- (void)resetExportState;
+
 // State of the export operation.
 @property(nonatomic, readonly, assign) ExportState exportState;
 

ios/chrome/browser/ui/settings/password_exporter.mm

@@ -15,6 +15,7 @@
 #include "components/password_manager/core/browser/export/password_csv_writer.h"
 #include "components/password_manager/core/browser/password_manager_metrics_util.h"
 #include "components/strings/grit/components_strings.h"
+#import "ios/chrome/browser/passwords/passwords_directory_util.h"
 #import "ios/chrome/browser/ui/settings/reauthentication_module.h"
 #include "ios/chrome/grit/ios_strings.h"
 #include "ui/base/l10n/l10n_util_mac.h"
@@ -62,6 +63,17 @@ enum class ReauthenticationStatus {
   WriteToURLStatus (^writeToFile)() = ^() {
     base::AssertBlockingAllowed();
     NSError* error = nil;
+
+    NSURL* directoryURL = [fileURL URLByDeletingLastPathComponent];
+    NSFileManager* fileManager = [NSFileManager defaultManager];
+
+    if (![fileManager createDirectoryAtURL:directoryURL
+               withIntermediateDirectories:YES
+                                attributes:nil
+                                     error:nil]) {
+      return WriteToURLStatus::UNKNOWN_ERROR;
+    }
+
     BOOL success = [data writeToURL:fileURL
                          atomically:YES
                            encoding:NSUTF8StringEncoding
@@ -258,9 +270,12 @@ enum class ReauthenticationStatus {
     [self resetExportState];
     return;
   }
-  NSURL* tempPasswordsFileURL =
-      [[NSURL fileURLWithPath:NSTemporaryDirectory() isDirectory:YES]
-          URLByAppendingPathComponent:_tempPasswordsFileName
+
+  NSURL* uniqueDirectoryURL = [GetPasswordsDirectoryURL()
+      URLByAppendingPathComponent:[[NSUUID UUID] UUIDString]
+                      isDirectory:YES];
+  NSURL* passwordsTempFileURL =
+      [uniqueDirectoryURL URLByAppendingPathComponent:_tempPasswordsFileName
                                           isDirectory:NO];
 
   __weak PasswordExporter* weakSelf = self;
@@ -275,7 +290,7 @@ enum class ReauthenticationStatus {
     }
     switch (status) {
       case WriteToURLStatus::SUCCESS:
-        [strongSelf showActivityView];
+        [strongSelf showActivityView:passwordsTempFileURL];
         break;
       case WriteToURLStatus::OUT_OF_DISK_SPACE_ERROR:
         [strongSelf
@@ -310,33 +325,26 @@ enum class ReauthenticationStatus {
   self.serializedPasswords = nil;
 
   [_passwordFileWriter writeData:serializedPasswords
-                           toURL:tempPasswordsFileURL
+                           toURL:passwordsTempFileURL
                          handler:onFileWritten];
 }
 
 - (void)deleteTemporaryFile:(NSURL*)passwordsTempFileURL {
-  __weak PasswordExporter* weakSelf = self;
-  base::PostTaskWithTraitsAndReply(
+  NSURL* uniqueDirectoryURL =
+      [passwordsTempFileURL URLByDeletingLastPathComponent];
+  base::PostTaskWithTraits(
       FROM_HERE, {base::MayBlock(), base::TaskPriority::BACKGROUND},
       base::BindBlockArc(^() {
         base::AssertBlockingAllowed();
         NSFileManager* fileManager = [NSFileManager defaultManager];
-        [fileManager removeItemAtURL:passwordsTempFileURL error:nil];
-      }),
-      base::BindBlockArc(^() {
-        [weakSelf resetExportState];
+        [fileManager removeItemAtURL:uniqueDirectoryURL error:nil];
       }));
 }
 
-- (void)showActivityView {
-  NSURL* passwordsTempFileURL =
-      [[NSURL fileURLWithPath:NSTemporaryDirectory() isDirectory:YES]
-          URLByAppendingPathComponent:_tempPasswordsFileName
-                          isDirectory:NO];
+- (void)showActivityView:(NSURL*)passwordsTempFileURL {
   if (self.exportState == ExportState::CANCELLING) {
-    // Initiate cleanup. Once the file is deleted, the export state will be
-    // reset;
     [self deleteTemporaryFile:passwordsTempFileURL];
+    [self resetExportState];
     return;
   }
   __weak PasswordExporter* weakSelf = self;

ios/chrome/browser/ui/settings/password_exporter_unittest.mm

@@ -56,6 +56,9 @@
 // error.
 @property(nonatomic, assign) WriteToURLStatus writingStatus;
 
+// Whether a write operation was attempted.
+@property(nonatomic, assign) BOOL writeAttempted;
+
 @end
 
 @implementation FakePasswordFileWriter {
@@ -64,10 +67,20 @@
 }
 
 @synthesize writingStatus = _writingStatus;
+@synthesize writeAttempted = _writeAttempted;
+
+- (instancetype)init {
+  self = [super init];
+  if (self) {
+    _writeAttempted = NO;
+  }
+  return self;
+}
 
 - (void)writeData:(NSString*)data
             toURL:(NSURL*)fileURL
           handler:(void (^)(WriteToURLStatus))handler {
+  _writeAttempted = YES;
   _writeStatusHandler = handler;
 }
 
@@ -104,30 +117,6 @@ class PasswordExporterTest : public PlatformTest {
     return password_forms;
   }
 
-  void TearDown() override {
-    NSURL* passwords_file_url = GetPasswordsFileURL();
-    if ([[NSFileManager defaultManager]
-            fileExistsAtPath:[passwords_file_url path]]) {
-      [[NSFileManager defaultManager] removeItemAtURL:passwords_file_url
-                                                error:nil];
-    }
-    PlatformTest::TearDown();
-  }
-
-  NSURL* GetPasswordsFileURL() {
-    NSString* passwords_file_name =
-        [l10n_util::GetNSString(IDS_PASSWORD_MANAGER_DEFAULT_EXPORT_FILENAME)
-            stringByAppendingString:@".csv"];
-    return [[NSURL fileURLWithPath:NSTemporaryDirectory() isDirectory:YES]
-        URLByAppendingPathComponent:passwords_file_name
-                        isDirectory:NO];
-  }
-
-  BOOL PasswordFileExists() {
-    return [[NSFileManager defaultManager]
-        fileExistsAtPath:[GetPasswordsFileURL() path]];
-  }
-
   id password_exporter_delegate_;
   PasswordExporter* password_exporter_;
   MockReauthenticationModule* mock_reauthentication_module_;
@@ -135,14 +124,17 @@ class PasswordExporterTest : public PlatformTest {
   base::HistogramTester histogram_tester_;
 };
 
-// Tests that when reauthentication is successful, the passwords file is written
-// and showing the activity view is requested.
+// Tests that when reauthentication is successful, writing the passwords file
+// is attempted and a call to show the activity view is made.
 TEST_F(PasswordExporterTest, PasswordFileWriteReauthSucceeded) {
   mock_reauthentication_module_.shouldSucceed = YES;
-  NSURL* passwords_file_url = GetPasswordsFileURL();
+  FakePasswordFileWriter* fake_password_file_writer =
+      [[FakePasswordFileWriter alloc] init];
+  fake_password_file_writer.writingStatus = WriteToURLStatus::SUCCESS;
+  [password_exporter_ setPasswordFileWriter:fake_password_file_writer];
 
   OCMExpect([password_exporter_delegate_
-      showActivityViewWithActivityItems:[OCMArg isEqual:@[ passwords_file_url ]]
+      showActivityViewWithActivityItems:[OCMArg any]
                       completionHandler:[OCMArg any]]);
 
   [password_exporter_ startExportFlow:CreatePasswordList()];
@@ -150,45 +142,12 @@ TEST_F(PasswordExporterTest, PasswordFileWriteReauthSucceeded) {
   // Wait for all asynchronous tasks to complete.
   scoped_task_environment_.RunUntilIdle();
 
-  EXPECT_TRUE(PasswordFileExists());
-  EXPECT_OCMOCK_VERIFY(password_exporter_delegate_);
-
-  histogram_tester_.ExpectTotalCount(
-      "PasswordManager.TimeReadingExportedPasswords", 1);
-  histogram_tester_.ExpectUniqueSample(
-      "PasswordManager.ExportPasswordsToCSVResult",
-      password_manager::metrics_util::ExportPasswordsResult::SUCCESS, 1);
-  histogram_tester_.ExpectUniqueSample(
-      "PasswordManager.ExportedPasswordsPerUserInCSV", 1, 1);
-}
-
-// Tests that the exporter becomes idle after the export finishes.
-TEST_F(PasswordExporterTest, ExportIdleAfterFinishing) {
-  mock_reauthentication_module_.shouldSucceed = YES;
-  NSURL* passwords_file_url = GetPasswordsFileURL();
-
-  OCMStub(
-      [password_exporter_delegate_
-          showActivityViewWithActivityItems:[OCMArg
-                                                isEqual:@[ passwords_file_url ]]
-                          completionHandler:[OCMArg any]])
-      .andDo(^(NSInvocation* invocation) {
-        void (^completionHandler)(NSString* activityType, BOOL completed,
-                                  NSArray* returnedItems,
-                                  NSError* activityError);
-        [invocation getArgument:&completionHandler atIndex:3];
-        // Since the completion handler doesn't use any of the
-        // passed in parameters, dummy arguments are passed for
-        // convenience.
-        completionHandler(@"", YES, @[], nil);
-      });
+  EXPECT_TRUE(fake_password_file_writer.writeAttempted);
 
-  [password_exporter_ startExportFlow:CreatePasswordList()];
-
-  // Wait for all asynchronous tasks to complete.
-  scoped_task_environment_.RunUntilIdle();
+  // Execute file write completion handler to continue the flow.
+  [fake_password_file_writer executeHandler];
 
-  EXPECT_EQ(ExportState::IDLE, password_exporter_.exportState);
+  EXPECT_OCMOCK_VERIFY(password_exporter_delegate_);
 
   histogram_tester_.ExpectTotalCount(
       "PasswordManager.TimeReadingExportedPasswords", 1);
@@ -297,6 +256,11 @@ TEST_F(PasswordExporterTest, ExportInterruptedWhenReauthFails) {
       [[FakePasswordSerialzerBridge alloc] init];
   [password_exporter_
       setPasswordSerializerBridge:fake_password_serializer_bridge];
+
+  FakePasswordFileWriter* fake_password_file_writer =
+      [[FakePasswordFileWriter alloc] init];
+  [password_exporter_ setPasswordFileWriter:fake_password_file_writer];
+
   [[password_exporter_delegate_ reject]
       showActivityViewWithActivityItems:[OCMArg any]
                       completionHandler:[OCMArg any]];
@@ -324,8 +288,8 @@ TEST_F(PasswordExporterTest, ExportInterruptedWhenReauthFails) {
   scoped_task_environment_.RunUntilIdle();
 
   // Serializing passwords has finished, but reauthentication was not
-  // successful, so the file is not written.
-  EXPECT_FALSE(PasswordFileExists());
+  // successful, so writing the file was not attempted.
+  EXPECT_FALSE(fake_password_file_writer.writeAttempted);
   EXPECT_EQ(ExportState::IDLE, password_exporter_.exportState);
 
   histogram_tester_.ExpectTotalCount(
@@ -346,6 +310,10 @@ TEST_F(PasswordExporterTest, CancelWaitsForSerializationFinished) {
   [password_exporter_
       setPasswordSerializerBridge:fake_password_serializer_bridge];
 
+  FakePasswordFileWriter* fake_password_file_writer =
+      [[FakePasswordFileWriter alloc] init];
+  [password_exporter_ setPasswordFileWriter:fake_password_file_writer];
+
   [[password_exporter_delegate_ reject]
       showActivityViewWithActivityItems:[OCMArg any]
                       completionHandler:[OCMArg any]];
@@ -366,7 +334,7 @@ TEST_F(PasswordExporterTest, CancelWaitsForSerializationFinished) {
     // is invoked. As this should not happen, mark the test as failed.
     GTEST_FAIL();
   }
-  EXPECT_FALSE(PasswordFileExists());
+  EXPECT_FALSE(fake_password_file_writer.writeAttempted);
   EXPECT_EQ(ExportState::IDLE, password_exporter_.exportState);
 
   histogram_tester_.ExpectTotalCount(

ios/chrome/browser/ui/settings/passwords_settings_egtest.mm

@@ -24,6 +24,7 @@
 #include "ios/chrome/browser/passwords/ios_chrome_password_store_factory.h"
 #import "ios/chrome/browser/ui/settings/reauthentication_module.h"
 #include "ios/chrome/browser/ui/tools_menu/public/tools_menu_constants.h"
+#include "ios/chrome/browser/ui/ui_util.h"
 #include "ios/chrome/grit/ios_strings.h"
 #import "ios/chrome/test/app/chrome_test_util.h"
 #import "ios/chrome/test/app/password_test_util.h"
@@ -57,6 +58,7 @@ using chrome_test_util::ButtonWithAccessibilityLabel;
 using chrome_test_util::SettingsMenuBackButton;
 using chrome_test_util::NavigationBarDoneButton;
 using chrome_test_util::SetUpAndReturnMockReauthenticationModule;
+using chrome_test_util::SetUpAndReturnMockReauthenticationModuleForExport;
 
 namespace {
 
@@ -1580,4 +1582,72 @@ PasswordForm CreateSampleFormWithIndex(int index) {
       assertWithMatcher:grey_notNil()];
 }
 
+// Test export flow
+- (void)testExportFlow {
+  if (!base::FeatureList::IsEnabled(
+          password_manager::features::kPasswordExport)) {
+    return;
+  }
+  // Saving a form is needed for exporting passwords.
+  SaveExamplePasswordForm();
+
+  OpenPasswordSettings();
+
+  MockReauthenticationModule* mock_reauthentication_module =
+      SetUpAndReturnMockReauthenticationModuleForExport();
+  mock_reauthentication_module.shouldSucceed = YES;
+
+  [[EarlGrey
+      selectElementWithMatcher:chrome_test_util::ButtonWithAccessibilityLabelId(
+                                   IDS_IOS_EXPORT_PASSWORDS)]
+      performAction:grey_tap()];
+
+  // Tap the alert's Export passwords... button to confirm. Check
+  // accessibilityTrait to differentiate against the above matching element,
+  // which has UIAccessibilityTraitSelected.
+  // TODO(crbug.com/751311): Revisit and check if there is a better solution to
+  // match the button.
+  id<GREYMatcher> exportConfirmationButton = grey_allOf(
+      ButtonWithAccessibilityLabel(
+          l10n_util::GetNSString(IDS_IOS_EXPORT_PASSWORDS)),
+      grey_not(grey_accessibilityTrait(UIAccessibilityTraitSelected)), nil);
+  [[EarlGrey selectElementWithMatcher:exportConfirmationButton]
+      performAction:grey_tap()];
+
+  // Wait until the alerts are dismissed.
+  [[GREYUIThreadExecutor sharedInstance] drainUntilIdle];
+
+  // Check that export button is disabled
+  [[EarlGrey
+      selectElementWithMatcher:chrome_test_util::ButtonWithAccessibilityLabelId(
+                                   IDS_IOS_EXPORT_PASSWORDS)]
+      assertWithMatcher:grey_accessibilityTrait(
+                            UIAccessibilityTraitNotEnabled)];
+
+  if (IsIPadIdiom()) {
+    // Tap outside the activity view to dismiss it, because it is not
+    // accompanied by a "Cancel" button on iPad.
+    [[EarlGrey selectElementWithMatcher:
+                   chrome_test_util::ButtonWithAccessibilityLabelId(
+                       IDS_IOS_EXPORT_PASSWORDS)] performAction:grey_tap()];
+  } else {
+    // Tap on the "Cancel" button accompanying the activity view to dismiss it.
+    [[EarlGrey
+        selectElementWithMatcher:grey_allOf(
+                                     ButtonWithAccessibilityLabel(@"Cancel"),
+                                     grey_interactable(), nullptr)]
+        performAction:grey_tap()];
+  }
+
+  // Wait until the activity view is dismissed.
+  [[GREYUIThreadExecutor sharedInstance] drainUntilIdle];
+
+  // Check that export button is re-enabled.
+  [[EarlGrey
+      selectElementWithMatcher:chrome_test_util::ButtonWithAccessibilityLabelId(
+                                   IDS_IOS_EXPORT_PASSWORDS)]
+      assertWithMatcher:grey_not(grey_accessibilityTrait(
+                            UIAccessibilityTraitNotEnabled))];
+}
+
 @end

ios/chrome/browser/ui/settings/save_passwords_collection_view_controller.mm

@@ -127,11 +127,51 @@ void SavePasswordsConsumer::OnGetPasswordStoreResults(
 @implementation BlacklistedFormContentItem
 @end
 
+@protocol PasswordExportActivityViewControllerDelegate<NSObject>
+
+// Used to reset the export state when the activity view disappears.
+- (void)resetExport;
+
+@end
+
+@interface PasswordExportActivityViewController : UIActivityViewController
+
+- (PasswordExportActivityViewController*)
+initWithActivityItems:(NSArray*)activityItems
+             delegate:
+                 (id<PasswordExportActivityViewControllerDelegate>)delegate;
+
+@end
+
+@implementation PasswordExportActivityViewController {
+  __weak id<PasswordExportActivityViewControllerDelegate> _weakDelegate;
+}
+
+- (PasswordExportActivityViewController*)
+initWithActivityItems:(NSArray*)activityItems
+             delegate:
+                 (id<PasswordExportActivityViewControllerDelegate>)delegate {
+  self = [super initWithActivityItems:activityItems applicationActivities:nil];
+  if (self) {
+    _weakDelegate = delegate;
+  }
+
+  return self;
+}
+
+- (void)viewDidDisappear:(BOOL)animated {
+  [_weakDelegate resetExport];
+  [super viewDidDisappear:animated];
+}
+
+@end
+
 @interface SavePasswordsCollectionViewController ()<
     BooleanObserver,
     PasswordDetailsCollectionViewControllerDelegate,
     SuccessfulReauthTimeAccessor,
-    PasswordExporterDelegate> {
+    PasswordExporterDelegate,
+    PasswordExportActivityViewControllerDelegate> {
   // The observable boolean that binds to the password manager setting state.
   // Saved passwords are only on if the password manager is enabled.
   PrefBackedBoolean* passwordManagerEnabled_;
@@ -516,10 +556,10 @@ void SavePasswordsConsumer::OnGetPasswordStoreResults(
   if (enabled) {
     DCHECK(exportReady_ && ![self.editor isEditing]);
     exportPasswordsItem_.textColor = [[MDCPalette greyPalette] tint900];
-    exportPasswordsItem_.accessibilityTraits = UIAccessibilityTraitButton;
+    exportPasswordsItem_.accessibilityTraits &= ~UIAccessibilityTraitNotEnabled;
   } else {
     exportPasswordsItem_.textColor = [[MDCPalette greyPalette] tint500];
-    exportPasswordsItem_.accessibilityTraits = UIAccessibilityTraitNotEnabled;
+    exportPasswordsItem_.accessibilityTraits |= UIAccessibilityTraitNotEnabled;
   }
   [self reconfigureCellsForItems:@[ exportPasswordsItem_ ]];
 }
@@ -858,9 +898,10 @@ void SavePasswordsConsumer::OnGetPasswordStoreResults(
                                                     NSArray* returnedItems,
                                                     NSError* activityError))
                                               completionHandler {
-  UIActivityViewController* activityViewController =
-      [[UIActivityViewController alloc] initWithActivityItems:activityItems
-                                        applicationActivities:nil];
+  PasswordExportActivityViewController* activityViewController =
+      [[PasswordExportActivityViewController alloc]
+          initWithActivityItems:activityItems
+                       delegate:self];
   NSArray* excludedActivityTypes = @[
     UIActivityTypeAddToReadingList, UIActivityTypeAirDrop,
     UIActivityTypeCopyToPasteboard, UIActivityTypeOpenInIBooks,
@@ -893,6 +934,14 @@ void SavePasswordsConsumer::OnGetPasswordStoreResults(
   [self presentViewController:activityViewController];
 }
 
+#pragma mark - PasswordExportActivityViewControllerDelegate
+
+- (void)resetExport {
+  [self.passwordExporter resetExportState];
+}
+
+#pragma mark Helper methods
+
 - (void)presentViewController:(UIViewController*)viewController {
   if (self.presentedViewController == preparingPasswordsAlert_ &&
       !preparingPasswordsAlert_.beingDismissed) {
@@ -908,8 +957,6 @@ void SavePasswordsConsumer::OnGetPasswordStoreResults(
   }
 }
 
-#pragma mark Helper methods
-
 // Sets the save passwords switch item's enabled status to |enabled| and
 // reconfigures the corresponding cell.
 - (void)setSavePasswordsSwitchItemEnabled:(BOOL)enabled {

ios/chrome/browser/ui/settings/save_passwords_collection_view_controller_unittest.mm

@@ -333,14 +333,16 @@ TEST_P(SavePasswordsCollectionViewControllerTest,
 
   UIColor* disabledColor = [[MDCPalette greyPalette] tint500];
   EXPECT_NSEQ(disabledColor, exportButton.textColor);
-  EXPECT_EQ(UIAccessibilityTraitNotEnabled, exportButton.accessibilityTraits);
+  EXPECT_TRUE(exportButton.accessibilityTraits &
+              UIAccessibilityTraitNotEnabled);
 
   // Add blacklisted form.
   AddBlacklistedForm1();
   // The export button should still be disabled as exporting blacklisted forms
   // is not currently supported.
   EXPECT_NSEQ(disabledColor, exportButton.textColor);
-  EXPECT_EQ(UIAccessibilityTraitNotEnabled, exportButton.accessibilityTraits);
+  EXPECT_TRUE(exportButton.accessibilityTraits &
+              UIAccessibilityTraitNotEnabled);
 }
 
 TEST_P(SavePasswordsCollectionViewControllerTest,
@@ -352,7 +354,8 @@ TEST_P(SavePasswordsCollectionViewControllerTest,
 
   CheckTextCellTitleWithId(IDS_IOS_EXPORT_PASSWORDS, 3, 0);
   EXPECT_NSEQ([[MDCPalette greyPalette] tint900], exportButton.textColor);
-  EXPECT_NE(UIAccessibilityTraitNotEnabled, exportButton.accessibilityTraits);
+  EXPECT_FALSE(exportButton.accessibilityTraits &
+               UIAccessibilityTraitNotEnabled);
 }
 
 // Tests that the "Export Passwords..." button is greyed out in edit mode.
@@ -371,7 +374,8 @@ TEST_P(SavePasswordsCollectionViewControllerTest,
       collectionViewWillBeginEditing:save_passwords_controller.collectionView];
 
   EXPECT_NSEQ([[MDCPalette greyPalette] tint500], exportButton.textColor);
-  EXPECT_EQ(UIAccessibilityTraitNotEnabled, exportButton.accessibilityTraits);
+  EXPECT_TRUE(exportButton.accessibilityTraits &
+              UIAccessibilityTraitNotEnabled);
 }
 
 // Tests that the "Export Passwords..." button is enabled after exiting
@@ -393,7 +397,8 @@ TEST_P(SavePasswordsCollectionViewControllerTest,
       collectionViewWillEndEditing:save_passwords_controller.collectionView];
 
   EXPECT_NSEQ([[MDCPalette greyPalette] tint900], exportButton.textColor);
-  EXPECT_NE(UIAccessibilityTraitNotEnabled, exportButton.accessibilityTraits);
+  EXPECT_FALSE(exportButton.accessibilityTraits &
+               UIAccessibilityTraitNotEnabled);
 }
 
 TEST_P(SavePasswordsCollectionViewControllerTest, PropagateDeletionToStore) {

ios/chrome/test/app/password_test_util.h

@@ -28,6 +28,11 @@ namespace chrome_test_util {
 // blocked with a reauth prompt, and return the fake reauthentication module.
 MockReauthenticationModule* SetUpAndReturnMockReauthenticationModule();
 
+// Replace the reauthentication module in
+// PasswordExporter with a fake one to avoid being
+// blocked with a reauth prompt, and return the fake reauthentication module.
+MockReauthenticationModule* SetUpAndReturnMockReauthenticationModuleForExport();
+
 }  // namespace chrome_test_util
 
 #endif  // IOS_CHROME_TEST_APP_PASSWORD_TEST_UTIL_H_

ios/chrome/test/app/password_test_util.mm

@@ -6,6 +6,7 @@
 
 #include "base/mac/foundation_util.h"
 #import "ios/chrome/browser/ui/settings/password_details_collection_view_controller_for_testing.h"
+#import "ios/chrome/browser/ui/settings/save_passwords_collection_view_controller.h"
 #import "ios/chrome/browser/ui/settings/settings_navigation_controller.h"
 #import "ios/chrome/browser/ui/util/top_view_controller.h"
 
@@ -60,4 +61,24 @@ MockReauthenticationModule* SetUpAndReturnMockReauthenticationModule() {
   return mock_reauthentication_module;
 }
 
+// Replace the reauthentication module in
+// PasswordExporter with a fake one to avoid being
+// blocked with a reauth prompt, and return the fake reauthentication module.
+MockReauthenticationModule*
+SetUpAndReturnMockReauthenticationModuleForExport() {
+  MockReauthenticationModule* mock_reauthentication_module =
+      [[MockReauthenticationModule alloc] init];
+  // TODO(crbug.com/754642): Stop using TopPresentedViewController();
+  SettingsNavigationController* settings_navigation_controller =
+      base::mac::ObjCCastStrict<SettingsNavigationController>(
+          top_view_controller::TopPresentedViewController());
+  SavePasswordsCollectionViewController*
+      save_passwords_collection_view_controller =
+          base::mac::ObjCCastStrict<SavePasswordsCollectionViewController>(
+              settings_navigation_controller.topViewController);
+  [save_passwords_collection_view_controller
+      setReauthenticationModuleForExporter:mock_reauthentication_module];
+  return mock_reauthentication_module;
+}
+
 }  // namespace