Introduce ManifestUpgradeDetector for WebAPK to detect web manifest changes.

chrome/browser/android/webapps/add_to_homescreen_data_fetcher.cc

Index: chrome/browser/android/webapps/add_to_homescreen_data_fetcher.cc
diff --git a/chrome/browser/android/webapps/add_to_homescreen_data_fetcher.cc b/chrome/browser/android/webapps/add_to_homescreen_data_fetcher.cc
index 0ffe0adf17e0b10b6f999a73923cb72753a5f130..022248dea93b621a9552db0be5d782e1548d9d3f 100644
--- a/chrome/browser/android/webapps/add_to_homescreen_data_fetcher.cc
+++ b/chrome/browser/android/webapps/add_to_homescreen_data_fetcher.cc
@@ -41,6 +41,7 @@ AddToHomescreenDataFetcher::AddToHomescreenDataFetcher(
     int minimum_icon_size_in_dp,
     int ideal_splash_image_size_in_dp,
     int minimum_splash_image_size_in_dp,
+    bool stop_fetch_when_no_manifest,
     Observer* observer)
     : WebContentsObserver(web_contents),
       weak_observer_(observer),
@@ -52,7 +53,8 @@ AddToHomescreenDataFetcher::AddToHomescreenDataFetcher(
       ideal_icon_size_in_dp_(ideal_icon_size_in_dp),
       minimum_icon_size_in_dp_(minimum_icon_size_in_dp),
       ideal_splash_image_size_in_dp_(ideal_splash_image_size_in_dp),
-      minimum_splash_image_size_in_dp_(minimum_splash_image_size_in_dp) {
+      minimum_splash_image_size_in_dp_(minimum_splash_image_size_in_dp),
+      stop_fetch_when_no_manifest_(stop_fetch_when_no_manifest) {
   DCHECK(minimum_icon_size_in_dp <= ideal_icon_size_in_dp);
   DCHECK(minimum_splash_image_size_in_dp <= ideal_splash_image_size_in_dp);
 
@@ -101,6 +103,19 @@ void AddToHomescreenDataFetcher::OnDidGetWebApplicationInfo(
       break;
   }
 
+  if (stop_fetch_when_no_manifest_) {
+    web_contents()->HasManifest(
+        base::Bind(&AddToHomescreenDataFetcher::OnDidHasManifest, this));
+  } else {
+    web_contents()->GetManifest(
+        base::Bind(&AddToHomescreenDataFetcher::OnDidGetManifest, this));
+  }
+}
+
+void AddToHomescreenDataFetcher::OnDidHasManifest(bool has_manifest) {
+  if (!has_manifest)
+    return;
+
   web_contents()->GetManifest(
       base::Bind(&AddToHomescreenDataFetcher::OnDidGetManifest, this));
 }
@@ -110,11 +125,17 @@ void AddToHomescreenDataFetcher::OnDidGetManifest(
     const content::Manifest& manifest) {
   if (!web_contents() || !weak_observer_) return;
 
+  if (stop_fetch_when_no_manifest_ && manifest.IsEmpty()) return;
+
+  weak_observer_->OnDidHasManifest(true);
   if (!manifest.IsEmpty()) {
       content::RecordAction(
           base::UserMetricsAction("webapps.AddShortcut.Manifest"));
       shortcut_info_.UpdateFromManifest(manifest);
       shortcut_info_.manifest_url = manifest_url;
+      icon_urls_.clear();
+      for (const auto& icon : manifest.icons)
+        icon_urls_.push_back(icon.src.spec());
   }
 
   GURL icon_src = ManifestIconSelector::FindBestMatchingIcon(
@@ -164,6 +185,11 @@ bool AddToHomescreenDataFetcher::OnMessageReceived(
   return handled;
 }
 
+void AddToHomescreenDataFetcher::ReplaceWebContents(
+    content::WebContents* web_contents) {
+  Observe(web_contents);
+}
+
 AddToHomescreenDataFetcher::~AddToHomescreenDataFetcher() {
   DCHECK(!weak_observer_);
 }
@@ -263,7 +289,7 @@ void AddToHomescreenDataFetcher::NotifyObserver(const SkBitmap& bitmap) {
   is_icon_saved_ = true;
   shortcut_icon_ = bitmap;
   is_ready_ = true;
-  weak_observer_->OnDataAvailable(shortcut_info_, shortcut_icon_);
+  weak_observer_->OnDataAvailable(shortcut_info_, shortcut_icon_, icon_urls_);
 }
 
 GURL AddToHomescreenDataFetcher::GetShortcutUrl(const GURL& actual_url) {