Add support to process favicons from Web Manifests

components/favicon/core/favicon_handler.h

Index: components/favicon/core/favicon_handler.h
diff --git a/components/favicon/core/favicon_handler.h b/components/favicon/core/favicon_handler.h
index 0e579b3ceaf97bf429979b23590f36a032deb1c5..82787e914a28611078a4f4e377e01a9112db9da9 100644
--- a/components/favicon/core/favicon_handler.h
+++ b/components/favicon/core/favicon_handler.h
@@ -13,6 +13,7 @@
 #include "base/cancelable_callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/optional.h"
 #include "base/task/cancelable_task_tracker.h"
 #include "components/favicon/core/favicon_driver_observer.h"
 #include "components/favicon/core/favicon_url.h"
@@ -23,10 +24,16 @@
 
 class SkBitmap;
 
+namespace base {
+struct Feature;
+}  // namespace base
+
 namespace favicon {
 
 class FaviconService;
 
+extern const base::Feature kFaviconsFromWebManifest;
+
 // FaviconHandler works with FaviconDriver to fetch the specific type of
 // favicon.
 //
@@ -99,6 +106,10 @@ class FaviconHandler {
         const std::vector<gfx::Size>& original_bitmap_sizes)>
         ImageDownloadCallback;
 
+    typedef base::Callback<void(
+        const std::vector<favicon::FaviconURL>& favicons)>
+        ManifestDownloadCallback;
+
     // Starts the download for the given favicon. When finished, the callback
     // is called with the results. Returns the unique id of the download
     // request, which will also be passed to the callback. In case of error, 0
@@ -111,6 +122,10 @@ class FaviconHandler {
                               int max_image_size,
                               ImageDownloadCallback callback) = 0;
 
+    // Downloads a WebManifest and returns the favicons listed there.
+    virtual void DownloadManifest(const GURL& url,
+                                  ManifestDownloadCallback callback) = 0;
+
     // Returns whether the user is operating in an off-the-record context.
     virtual bool IsOffTheRecord() = 0;
 
@@ -137,10 +152,15 @@ class FaviconHandler {
   // Initiates loading the favicon for the specified url.
   void FetchFavicon(const GURL& url);
 
-  // Message Handler.  Must be public, because also called from
-  // PrerenderContents. Collects the |image_urls| list.
+  // Collects the candidate favicons as listed in the HTML head, as well as
+  // the WebManifest URL if available.
   void OnUpdateCandidates(const GURL& page_url,
-                          const std::vector<favicon::FaviconURL>& candidates);
+                          const std::vector<favicon::FaviconURL>& candidates,
+                          const base::Optional<GURL>& manifest_url);
+
+  // Returns the supported icon types, inferred from the handler type as passed
+  // in the constructor.
+  int icon_types() const { return icon_types_; }
 
   // For testing.
   const std::vector<GURL> GetIconURLs() const;
@@ -187,6 +207,20 @@ class FaviconHandler {
   static int GetIconTypesFromHandlerType(
       FaviconDriverObserver::NotificationIconType handler_type);
 
+  // Called with the result of looking up cached icon data for the manifest's
+  // URL, which is used as icon URL.
+  void OnFaviconDataForManifestFromFaviconService(
+      const std::vector<favicon_base::FaviconRawBitmapResult>&
+          favicon_bitmap_results);
+
+  // Called when the dowloading of a manifest completes.
+  void OnDidDownloadManifest(const std::vector<FaviconURL>& candidates);
+
+  // Called when the actual list of favicon candidates to be processed is
+  // available, which can be either icon URLs listed in the HTML head instead
+  // or, if a Web Manifest was provided, the list of icons there.
+  void OnGotFinalIconURLCandidates(const std::vector<FaviconURL>& candidates);
+
   // Called when the history request for favicon data mapped to |url_| has
   // completed and the renderer has told us the icon URLs used by |url_|
   void OnGotInitialHistoryDataAndIconURLCandidates();
@@ -201,6 +235,13 @@ class FaviconHandler {
   // OnFaviconData() is called with the history data once it has been retrieved.
   void DownloadCurrentCandidateOrAskFaviconService();
 
+  // Requests the favicon for |icon_url| from the favicon service. Unless in
+  // incognito, it also updates the page URL (url_) to |icon_url| mappings.
+  void GetFaviconAndUpdateMappingsUnlessIncognito(
+      const GURL& icon_url,
+      favicon_base::IconType icon_type,
+      const favicon_base::FaviconResultsCallback& callback);
+
   // See description above class for details.
   void OnFaviconData(const std::vector<favicon_base::FaviconRawBitmapResult>&
                          favicon_bitmap_results);
@@ -283,6 +324,10 @@ class FaviconHandler {
   // |image_urls_| one by one.
   bool redownload_icons_;
 
+  // Requests to the renderer to download a manifest.
+  base::CancelableCallback<Delegate::ManifestDownloadCallback::RunType>
+      manifest_download_request_;
+
   // Requests to the renderer to download favicons.
   base::CancelableCallback<Delegate::ImageDownloadCallback::RunType>
       image_download_request_;
@@ -293,6 +338,14 @@ class FaviconHandler {
   // Whether the largest icon should be downloaded.
   const bool download_largest_icon_;
 
+  // The manifest URL from the renderer.
+  base::Optional<GURL> manifest_url_;
+
+  // Original list of candidates provided to OnUpdateCandidates(), stored to
+  // be able to fall back to, in case a manifest was provided and downloading it
+  // failed (or provided no icons).
+  std::vector<FaviconURL> non_manifest_original_candidates_;
+
   // The prioritized favicon candidates from the page back from the renderer.
   std::vector<FaviconCandidate> candidates_;