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 2b647326e23d618c591d55348a9d47c8026b3cd5..736a9a1b56112fa1c445fb6c4efd01a69f1787e9 100644
--- a/chrome/browser/banners/app_banner_data_fetcher.cc
+++ b/chrome/browser/banners/app_banner_data_fetcher.cc
@@ -115,6 +115,9 @@ 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);

[benwells, 2016/07/05 05:34:49]

Nit: This name is a bit misleading, I think it means
PROMPT_NOT_CALLED_AFTER_PREVENT_DEFAULT, is that right?

[dominickn, 2016/07/05 06:00:09]

Done.

+
     is_active_ = false;
     was_canceled_by_page_ = false;
     page_requested_prompt_ = false;
@@ -188,6 +191,7 @@ 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);
     was_canceled_by_page_ = true;
     referrer_ = referrer;
     OutputDeveloperNotShownMessage(web_contents, kRendererRequestCancel,
@@ -202,6 +206,7 @@ void AppBannerDataFetcher::OnBannerPromptReply(
   FOR_EACH_OBSERVER(Observer, observer_list_,
                     OnDecidedWhetherToShow(this, true));
 
+  TrackBeforeInstallEvent(BEFORE_INSTALL_EVENT_COMPLETE);
   ShowBanner(app_icon_url_, app_icon_.get(), app_title_, referrer);
   is_active_ = false;
 }
@@ -209,6 +214,8 @@ void AppBannerDataFetcher::OnBannerPromptReply(
 void AppBannerDataFetcher::OnRequestShowAppBanner(
     content::RenderFrameHost* render_frame_host,
     int request_id) {
+  TrackBeforeInstallEvent(BEFORE_INSTALL_EVENT_PROMPT_CALLED);
+
   if (was_canceled_by_page_) {
     // Simulate an "OK" from the website to restart the banner display pipeline.
     was_canceled_by_page_ = false;
@@ -401,6 +408,8 @@ 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(),