[sms] Replace current infobar if one exists

This CL replaces the current infobars if there are existing ones by
removing them.

Bug: 999222
Change-Id: Id3d84ca24a935c6c3420dfeb8194d0610278a631
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1775213
Commit-Queue: Jun Cai <juncai@chromium.org>
Reviewed-by: Ayu Ishii <ayui@chromium.org>
Cr-Commit-Position: refs/heads/master@{#692123}

chrome/browser/ui/android/sms/sms_infobar.cc

@@ -27,7 +27,8 @@ void SmsInfoBar::Create(content::WebContents* web_contents,
   auto infobar =
       std::make_unique<SmsInfoBar>(web_contents, std::move(delegate));
   auto* infobar_service = InfoBarService::FromWebContents(web_contents);
-  infobar_service->AddInfoBar(std::move(infobar));
+  infobar_service->RemoveAllInfoBars(/*animate=*/false);
+  infobar_service->AddInfoBar(std::move(infobar), /*replace_existing=*/true);
 }
 
 SmsInfoBar::SmsInfoBar(content::WebContents* web_contents,