Replace deprecated getLastUsedProfile function in

PassphraseDialogFragment.

|Profile#getLastUsedProfile| is deprecated and replaced with
|Profile#getLastUsedRegularProfile|. This CL updates
PassphraseDialogFragment class.

Note: This change is only code clean-up, does not change any behavior.

Bug: 1041781
Change-Id: I3153d152820781be684fc0fd0a7ff00d45c6981b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2082912Reviewed-by: Marc Treib <treib@chromium.org>
Reviewed-by: Ramin Halavati <rhalavati@chromium.org>
Commit-Queue: Side YILMAZ <sideyilmaz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#746353}

chrome/android/java/src/org/chromium/chrome/browser/sync/ui/PassphraseDialogFragment.java

@@ -182,8 +182,12 @@ public class PassphraseDialogFragment extends DialogFragment implements OnClickL
                 new SpanInfo("<learnmore>", "</learnmore>", new ClickableSpan() {
                     @Override
                     public void onClick(View view) {
-                        HelpAndFeedback.getInstance().show(
-                                getActivity(), helpContext, Profile.getLastUsedProfile(), null);
+                        // TODO(https://crbug.com/1048632): It works correctly now, but unsafe
+                        // if sync runs in incognito mode ever. Use the current profile (i.e.,
+                        // regular profile or incognito profile) instead of always using regular
+                        // profile.
+                        HelpAndFeedback.getInstance().show(getActivity(), helpContext,
+                                Profile.getLastUsedRegularProfile(), null);
                     }
                 }));
     }