Allow app banners to be triggered by increases in site engagement.

chrome/browser/banners/app_banner_manager.cc

Index: chrome/browser/banners/app_banner_manager.cc
diff --git a/chrome/browser/banners/app_banner_manager.cc b/chrome/browser/banners/app_banner_manager.cc
index e20ec795e24a02780581ddb694caf39cd9ede993..4e8aac325a4d7d6460252913e438260b6874969f 100644
--- a/chrome/browser/banners/app_banner_manager.cc
+++ b/chrome/browser/banners/app_banner_manager.cc
@@ -7,12 +7,13 @@
 #include "chrome/browser/banners/app_banner_data_fetcher.h"
 #include "chrome/browser/banners/app_banner_debug_log.h"
 #include "chrome/browser/banners/app_banner_settings_helper.h"
-#include "content/public/browser/navigation_details.h"
+#include "chrome/browser/engagement/site_engagement_service.h"
+#include "chrome/browser/profiles/profile.h"
+#include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/frame_navigate_params.h"
 #include "content/public/common/origin_util.h"
-#include "net/base/load_flags.h"
 
 namespace {
 bool gDisableSecureCheckForTesting = false;
@@ -36,15 +37,12 @@ bool AppBannerManager::URLsAreForTheSamePage(const GURL& first,
          first.path() == second.path() && first.query() == second.query();
 }
 
-AppBannerManager::AppBannerManager()
-    : data_fetcher_(nullptr),
-      weak_factory_(this) {
-  AppBannerSettingsHelper::UpdateFromFieldTrial();
-}
-
 AppBannerManager::AppBannerManager(content::WebContents* web_contents)
     : content::WebContentsObserver(web_contents),
+      SiteEngagementObserver(nullptr),
       data_fetcher_(nullptr),
+      banner_request_queued_(false),
+      load_finished_(false),
       weak_factory_(this) {
   AppBannerSettingsHelper::UpdateFromFieldTrial();
 }
@@ -54,7 +52,7 @@ AppBannerManager::~AppBannerManager() {
 }
 
 void AppBannerManager::ReplaceWebContents(content::WebContents* web_contents) {
-  Observe(web_contents);
+  content::WebContentsObserver::Observe(web_contents);
   if (data_fetcher_.get())
     data_fetcher_.get()->ReplaceWebContents(web_contents);
 }
@@ -63,18 +61,11 @@ bool AppBannerManager::IsFetcherActive() {
   return data_fetcher_ && data_fetcher_->is_active();
 }
 
-void AppBannerManager::DidNavigateMainFrame(
-    const content::LoadCommittedDetails& details,
-    const content::FrameNavigateParams& params) {
-  last_transition_type_ = params.transition;
-}
-
-void AppBannerManager::RequestAppBanner(
-    content::RenderFrameHost* render_frame_host,
-    const GURL& validated_url,
-    bool is_debug_mode) {
-  if (render_frame_host->GetParent()) {
-    OutputDeveloperNotShownMessage(web_contents(), kNotLoadedInMainFrame,
+void AppBannerManager::RequestAppBanner(const GURL& validated_url,
+                                        bool is_debug_mode) {
+  content::WebContents* contents = web_contents();
+  if (contents->GetMainFrame()->GetParent()) {
+    OutputDeveloperNotShownMessage(contents, kNotLoadedInMainFrame,
                                    is_debug_mode);
     return;
   }
@@ -89,7 +80,7 @@ void AppBannerManager::RequestAppBanner(
   // URL is invalid.
   if (!content::IsOriginSecure(validated_url) &&
       !gDisableSecureCheckForTesting) {
-    OutputDeveloperNotShownMessage(web_contents(), kNotServedFromSecureOrigin,
+    OutputDeveloperNotShownMessage(contents, kNotServedFromSecureOrigin,
                                    is_debug_mode);
     return;
   }
@@ -100,12 +91,54 @@ void AppBannerManager::RequestAppBanner(
   data_fetcher_->Start(validated_url, last_transition_type_);
 }
 
+void AppBannerManager::DidStartNavigation(
+    content::NavigationHandle* navigation_handle) {
+  if (!navigation_handle->IsInMainFrame())
+    return;
+
+  load_finished_ = false;
+  if (AppBannerSettingsHelper::ShouldUseSiteEngagementScore() &&
+      GetSiteEngagementService() == nullptr) {
+    // Ensure that we are observing the site engagement service on navigation
+    // start. This may be the first navigation, or we may have stopped
+    // observing if the banner flow was triggered on the previous page.
+    SiteEngagementObserver::Observe(SiteEngagementService::Get(
+        Profile::FromBrowserContext(web_contents()->GetBrowserContext())));
+  }
+}
+
+void AppBannerManager::DidFinishNavigation(
+    content::NavigationHandle* navigation_handle) {
+  if (navigation_handle->HasCommitted())
+    last_transition_type_ = navigation_handle->GetPageTransition();
+}
+
 void AppBannerManager::DidFinishLoad(
     content::RenderFrameHost* render_frame_host,
     const GURL& validated_url) {
-  // The third argument is the is_debug_mode boolean value, which is true only
-  // when it is triggered by the developer's action in DevTools.
-  RequestAppBanner(render_frame_host, validated_url, false /* is_debug_mode */);
+  // Don't start the banner flow unless the main frame has finished loading.
+  if (render_frame_host->GetParent())
+    return;
+
+  load_finished_ = true;
+  if (!AppBannerSettingsHelper::ShouldUseSiteEngagementScore() ||
+      banner_request_queued_) {
+    banner_request_queued_ = false;
+
+    // The third argument is the is_debug_mode boolean value, which is true only
+    // when it is triggered by the developer's action in DevTools.
+    RequestAppBanner(validated_url, false /* is_debug_mode */);
+  }
+}
+
+void AppBannerManager::MediaStartedPlaying(const MediaPlayerId& id) {
+  active_media_players_.push_back(id);
+}
+
+void AppBannerManager::MediaStoppedPlaying(const MediaPlayerId& id) {
+  active_media_players_.erase(std::remove(active_media_players_.begin(),
+                                          active_media_players_.end(), id),
+                              active_media_players_.end());
 }
 
 bool AppBannerManager::HandleNonWebApp(const std::string& platform,
@@ -115,6 +148,30 @@ bool AppBannerManager::HandleNonWebApp(const std::string& platform,
   return false;
 }
 
+void AppBannerManager::OnEngagementIncreased(content::WebContents* contents,
+                                             const GURL& url,
+                                             double score) {
+  // Only trigger a banner using site engagement if:
+  //  1. engagement increased for the web contents which we are attached to; and
+  //  2. there are no currently active media players; and
+  //  3. we have accumulated sufficient engagement.
+  if (web_contents() == contents && active_media_players_.empty() &&
+      AppBannerSettingsHelper::HasSufficientEngagement(score)) {
+    // Stop observing so we don't double-trigger the banner.
+    SiteEngagementObserver::Observe(nullptr);
+
+    if (!load_finished_) {
+      // Wait until the main frame finishes loading before requesting a banner.
+      banner_request_queued_ = true;
+    } else {
+      // Requesting a banner performs some simple tests, creates a data fetcher,
+      // and starts some asynchronous checks to test installability. It should
+      // be safe to start this in response to user input.
+      RequestAppBanner(url, false /* is_debug_mode */);
+    }
+  }
+}
+
 void AppBannerManager::CancelActiveFetcher() {
   if (data_fetcher_) {
     data_fetcher_->Cancel();