Add metrics for app banner preventDefault() and prompt().

chrome/browser/banners/app_banner_data_fetcher.cc

Index: chrome/browser/banners/app_banner_data_fetcher.cc
diff --git a/chrome/browser/banners/app_banner_data_fetcher.cc b/chrome/browser/banners/app_banner_data_fetcher.cc
index 48589c0116663d3e26774bee7ecd8002a1145b9f..d01dbfee5c7566204f9426aa39bdfa6d1e5c4a9a 100644
--- a/chrome/browser/banners/app_banner_data_fetcher.cc
+++ b/chrome/browser/banners/app_banner_data_fetcher.cc
@@ -115,6 +115,11 @@ void AppBannerDataFetcher::Cancel() {
   if (is_active_) {
     FOR_EACH_OBSERVER(Observer, observer_list_,
                       OnDecidedWhetherToShow(this, false));
+    if (was_canceled_by_page_ && !page_requested_prompt_) {
+      TrackBeforeInstallEvent(
+          BEFORE_INSTALL_EVENT_PROMPT_NOT_CALLED_AFTER_PREVENT_DEFAULT);
+    }
+
     is_active_ = false;
     was_canceled_by_page_ = false;
     page_requested_prompt_ = false;
@@ -188,6 +193,7 @@ void AppBannerDataFetcher::OnBannerPromptReply(
   // Stash the referrer for the case where the banner is redisplayed.
   if (reply == blink::WebAppBannerPromptReply::Cancel &&
       !page_requested_prompt_) {
+    TrackBeforeInstallEvent(BEFORE_INSTALL_EVENT_PREVENT_DEFAULT_CALLED);
     was_canceled_by_page_ = true;
     referrer_ = referrer;
     OutputDeveloperNotShownMessage(web_contents, kRendererRequestCancel,
@@ -195,6 +201,17 @@ void AppBannerDataFetcher::OnBannerPromptReply(
     return;
   }
 
+  // If we haven't yet returned, but either of |was_canceled_by_page_| or
+  // |page_requested_prompt_| is true, the page has requested a delayed showing
+  // of the prompt. Otherwise, the prompt was never canceled by the page.
+  if (was_canceled_by_page_ || page_requested_prompt_) {
+    TrackBeforeInstallEvent(
+        BEFORE_INSTALL_EVENT_PROMPT_CALLED_AFTER_PREVENT_DEFAULT);
+    was_canceled_by_page_ = false;
+  } else {
+    TrackBeforeInstallEvent(BEFORE_INSTALL_EVENT_NO_ACTION);
+  }
+
   AppBannerSettingsHelper::RecordMinutesFromFirstVisitToShow(
       web_contents, validated_url_, GetAppIdentifier(), GetCurrentTime());
 
@@ -202,6 +219,7 @@ void AppBannerDataFetcher::OnBannerPromptReply(
   FOR_EACH_OBSERVER(Observer, observer_list_,
                     OnDecidedWhetherToShow(this, true));
 
+  TrackBeforeInstallEvent(BEFORE_INSTALL_EVENT_COMPLETE);
   ShowBanner(app_icon_.get(), app_title_, referrer);
   is_active_ = false;
 }
@@ -211,7 +229,7 @@ void AppBannerDataFetcher::OnRequestShowAppBanner(
     int request_id) {
   if (was_canceled_by_page_) {
     // Simulate an "OK" from the website to restart the banner display pipeline.
-    was_canceled_by_page_ = false;
+    // Don't reset |was_canceled_by_page_| yet for metrics purposes.
     OnBannerPromptReply(render_frame_host, request_id,
                         blink::WebAppBannerPromptReply::None, referrer_);
   } else {
@@ -403,6 +421,8 @@ void AppBannerDataFetcher::OnAppIconFetched(const SkBitmap& bitmap) {
 
   app_icon_.reset(new SkBitmap(bitmap));
   event_request_id_ = ++gCurrentRequestID;
+
+  TrackBeforeInstallEvent(BEFORE_INSTALL_EVENT_CREATED);
   web_contents->GetMainFrame()->Send(
       new ChromeViewMsg_AppBannerPromptRequest(
         web_contents->GetMainFrame()->GetRoutingID(),