[Android][Test] Test error metrics in web sign-in flow

This CL tests the error metrics recording in the web sign-in flow.

Bug: 1139244
Change-Id: I2c5254afafb71388eeb86d1759e8c808331124e4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2484652Reviewed-by: Tanmoy Mollik <triploblastic@chromium.org>
Commit-Queue: Alice Wang <aliceywang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#818405}

chrome/android/javatests/src/org/chromium/chrome/browser/signin/AccountPickerBottomSheetTest.java

@@ -386,6 +386,9 @@ public class AccountPickerBottomSheetTest {
     @Test
     @MediumTest
     public void testSignInGeneralError() {
+        MetricsUtils.HistogramDelta accountConsistencyHistogram =
+                new HistogramDelta("Signin.AccountConsistencyPromoAction",
+                        AccountConsistencyPromoAction.GENERIC_ERROR_SHOWN);
         // Throws a connection error during the sign-in action
         doAnswer(invocation -> {
             Callback<GoogleServiceAuthError> onSignInErrorCallback = invocation.getArgument(1);
@@ -409,11 +412,15 @@ public class AccountPickerBottomSheetTest {
         onView(withId(R.id.account_picker_selected_account)).check(matches(not(isDisplayed())));
         onView(withId(R.id.account_picker_signin_spinner_view)).check(matches(not(isDisplayed())));
         onView(withId(R.id.account_picker_dismiss_button)).check(matches(not(isDisplayed())));
+        Assert.assertEquals(1, accountConsistencyHistogram.getDelta());
     }
 
     @Test
     @MediumTest
     public void testSignInAuthError() {
+        MetricsUtils.HistogramDelta accountConsistencyHistogram =
+                new HistogramDelta("Signin.AccountConsistencyPromoAction",
+                        AccountConsistencyPromoAction.AUTH_ERROR_SHOWN);
         CoreAccountInfo coreAccountInfo =
                 mAccountManagerTestRule.toCoreAccountInfo(PROFILE_DATA1.getAccountName());
         // Throws an auth error during the sign-in action
@@ -437,6 +444,7 @@ public class AccountPickerBottomSheetTest {
         onView(withId(R.id.account_picker_selected_account)).check(matches(not(isDisplayed())));
         onView(withId(R.id.account_picker_signin_spinner_view)).check(matches(not(isDisplayed())));
         onView(withId(R.id.account_picker_dismiss_button)).check(matches(not(isDisplayed())));
+        Assert.assertEquals(1, accountConsistencyHistogram.getDelta());
     }
 
     @Test