[Android] Add signin FRE render test when no accounts on device

This CL adds a render test for SigninFirstRunFragment when no accounts
are on device.

Bug: 1045473
Change-Id: I058212677f7f4cb0d29888632f12d2fabd75ded0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2639895Reviewed-by: Tanmoy Mollik <triploblastic@chromium.org>
Commit-Queue: Alice Wang <aliceywang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#845624}

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

@@ -180,6 +180,35 @@ public class SigninFragmentTest {
                 "signin_fragment_default_account");
     }
 
+    @Test
+    @LargeTest
+    @Feature("RenderTest")
+    public void testSigninFREFragmentWithNoAccountsOnDevice() throws IOException {
+        HistogramDelta countHistogram =
+                new HistogramDelta("Signin.AndroidDeviceAccountsNumberWhenEnteringFRE", 0);
+        HistogramDelta startPageHistogram =
+                new HistogramDelta("Signin.SigninStartedAccessPoint", SigninAccessPoint.START_PAGE);
+        CustomSigninFirstRunFragment fragment = new CustomSigninFirstRunFragment();
+        Bundle bundle = new Bundle();
+        bundle.putInt(SigninFirstRunFragment.CHILD_ACCOUNT_STATUS, ChildAccountStatus.NOT_CHILD);
+        when(mFirstRunPageDelegateMock.getProperties()).thenReturn(bundle);
+        fragment.setPageDelegate(mFirstRunPageDelegateMock);
+
+        mActivityTestRule.launchActivity(null);
+        TestThreadUtils.runOnUiThreadBlocking(() -> {
+            mActivityTestRule.getActivity()
+                    .getSupportFragmentManager()
+                    .beginTransaction()
+                    .add(android.R.id.content, fragment)
+                    .commit();
+        });
+        ApplicationTestUtils.waitForActivityState(mActivityTestRule.getActivity(), Stage.RESUMED);
+        Assert.assertEquals(1, countHistogram.getDelta());
+        Assert.assertEquals(1, startPageHistogram.getDelta());
+        mRenderTestRule.render(mActivityTestRule.getActivity().findViewById(android.R.id.content),
+                "signin_fre_fragment_with_no_account");
+    }
+
     @Test
     @LargeTest
     @Feature("RenderTest")