[App banners] Add browser test for canceling banners

chrome/browser/banners/app_banner_data_fetcher.cc

 // Copyright 2015 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 "chrome/browser/banners/app_banner_data_fetcher.h"
 
 #include "base/bind.h"
 #include "base/strings/string_util.h"
 #include "chrome/browser/banners/app_banner_metrics.h"
 #include "chrome/browser/banners/app_banner_settings_helper.h"
@@ skipping 122 matching lines @@
 
 void AppBannerDataFetcher::OnBannerPromptReply(
     content::RenderFrameHost* render_frame_host,
     int request_id,
     blink::WebAppBannerPromptReply reply) {
   content::WebContents* web_contents = GetWebContents();
   if (!is_active_ || !web_contents || request_id != gCurrentRequestID) {
     Cancel();
     return;
   }
-  is_active_ = false;
 
   // The renderer might have requested the prompt to be canceled.
   if (reply == blink::WebAppBannerPromptReply::Cancel) {
     // TODO(mlamouri,benwells): we should probably record that to behave
     // differently with regard to showing the banner.
     Cancel();
     return;
   }
 
   // Definitely going to show the banner now.
   FOR_EACH_OBSERVER(Observer, observer_list_,
                     OnDecidedWhetherToShow(this, true));
 
   infobars::InfoBar* infobar = CreateBanner(app_icon_.get(), app_title_);
   if (infobar) {
     InfoBarService::FromWebContents(web_contents)->AddInfoBar(
         make_scoped_ptr(infobar));
   }
+  is_active_ = false;
 }
 
 AppBannerDataFetcher::~AppBannerDataFetcher() {
   FOR_EACH_OBSERVER(Observer, observer_list_, OnFetcherDestroyed(this));
 }
 
 std::string AppBannerDataFetcher::GetBannerType() {
   return "web";
 }
 
@@ skipping 169 matching lines @@
   if (!manifest.start_url.is_valid())
     return false;
   if (manifest.name.is_null() && manifest.short_name.is_null())
     return false;
   if (!DoesManifestContainRequiredIcon(manifest))
     return false;
   return true;
 }
 
 }  // namespace banners