Add support to process favicons from Web Manifests

components/favicon/content/content_favicon_driver.h

Index: components/favicon/content/content_favicon_driver.h
diff --git a/components/favicon/content/content_favicon_driver.h b/components/favicon/content/content_favicon_driver.h
index 54a68884d81a94369bf52e3f7905004029f6fa29..b768e033ed6aee781ec1462d0fe1a19bd60c2e45 100644
--- a/components/favicon/content/content_favicon_driver.h
+++ b/components/favicon/content/content_favicon_driver.h
@@ -6,10 +6,12 @@
 #define COMPONENTS_FAVICON_CONTENT_CONTENT_FAVICON_DRIVER_H_
 
 #include "base/macros.h"
+#include "base/optional.h"
 #include "components/favicon/core/favicon_driver_impl.h"
 #include "content/public/browser/reload_type.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
+#include "content/public/common/favicon_url.h"
 #include "url/gurl.h"
 
 namespace content {
@@ -36,8 +38,8 @@ class ContentFaviconDriver
 
   // Returns the current tab's favicon URLs. If this is empty,
   // DidUpdateFaviconURL has not yet been called for the current navigation.
-  const std::vector<content::FaviconURL>& favicon_urls() const {
-    return favicon_urls_;
+  std::vector<content::FaviconURL> favicon_urls() const {
+    return favicon_urls_.value_or(std::vector<content::FaviconURL>());
   }
 
   // Saves the favicon for the last committed navigation entry to the thumbnail
@@ -62,6 +64,8 @@ class ContentFaviconDriver
   int DownloadImage(const GURL& url,
                     int max_image_size,
                     ImageDownloadCallback callback) override;
+  void DownloadManifest(const GURL& url,
+                        ManifestDownloadCallback callback) override;
   bool IsOffTheRecord() override;
   void OnFaviconUpdated(const GURL& page_url,
                         FaviconDriverObserver::NotificationIconType icon_type,
@@ -72,13 +76,18 @@ class ContentFaviconDriver
   // content::WebContentsObserver implementation.
   void DidUpdateFaviconURL(
       const std::vector<content::FaviconURL>& candidates) override;
+  void DidUpdateWebManifestURL(
+      const base::Optional<GURL>& manifest_url) override;
   void DidStartNavigation(
       content::NavigationHandle* navigation_handle) override;
   void DidFinishNavigation(
       content::NavigationHandle* navigation_handle) override;
 
   GURL bypass_cache_page_url_;
-  std::vector<content::FaviconURL> favicon_urls_;
+  // nullopt until the actual list is reported via DidUpdateFaviconURL().
+  base::Optional<std::vector<content::FaviconURL>> favicon_urls_;
+  // Web Manifest URL or empty URL if none.
+  GURL manifest_url_;
 
   DISALLOW_COPY_AND_ASSIGN(ContentFaviconDriver);
 };