Handle per-tab AUTOMATIC_DOWNLOADS setting in DownloadRequestLimiter.

chrome/browser/download/download_request_limiter.h

Index: chrome/browser/download/download_request_limiter.h
diff --git a/chrome/browser/download/download_request_limiter.h b/chrome/browser/download/download_request_limiter.h
index 63d13c5fcdc4ff9add900a2159254adf6adaf158..02ecf11fcd30e0e2b12903f1b007062b0b251002 100644
--- a/chrome/browser/download/download_request_limiter.h
+++ b/chrome/browser/download/download_request_limiter.h
@@ -16,9 +16,9 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
+#include "base/scoped_observer.h"
+#include "components/content_settings/core/browser/content_settings_observer.h"
 #include "components/content_settings/core/common/content_settings.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/resource_request_info.h"
 #include "content/public/browser/web_contents_observer.h"
 
@@ -74,7 +74,7 @@ class DownloadRequestLimiter
   // TabDownloadState deletes itself (by invoking
   // DownloadRequestLimiter::Remove) as necessary.
   // TODO(gbillock): just make this class implement PermissionRequest.
-  class TabDownloadState : public content::NotificationObserver,
+  class TabDownloadState : public content_settings::Observer,
                            public content::WebContentsObserver {
    public:
     // Creates a new TabDownloadState. |controller| is the controller the
@@ -89,9 +89,8 @@ class DownloadRequestLimiter
     ~TabDownloadState() override;
 
     // Status of the download.

[dominickn, 2017/01/24 06:46:17]

Nit: "Sets the current limiter state and the underlying automatic downloads
content setting. Sends a notification that the content setting has been changed
(if it has changed)"

[alshabalin, 2017/02/07 16:16:29]

Done.

-    void set_download_status(DownloadRequestLimiter::DownloadStatus status) {
-      status_ = status;
-    }
+    void SetDownloadStatusAndNotify(
+        DownloadRequestLimiter::DownloadStatus status);
     DownloadRequestLimiter::DownloadStatus download_status() const {
       return status_;
     }
@@ -136,17 +135,19 @@ class DownloadRequestLimiter
     // given to the info bar delegate or permission bubble request.
     bool is_showing_prompt() const;
 
-    // content::NotificationObserver method.
-    void Observe(int type,
-                 const content::NotificationSource& source,
-                 const content::NotificationDetails& details) override;
+    // content_settings::Observer overrides.
+    void OnContentSettingChanged(
+        const ContentSettingsPattern& primary_pattern,
+        const ContentSettingsPattern& secondary_pattern,
+        ContentSettingsType content_type,
+        std::string resource_identifier) override;
 
     // Remember to either block or allow automatic downloads from this origin.
     void SetContentSetting(ContentSetting setting);
 
     // Notifies the callbacks as to whether the download is allowed or not.
-    // Updates status_ appropriately.
-    void NotifyCallbacks(bool allow);
+    // Returns false if it didn't notify all callbacks.
+    bool NotifyCallbacks(bool allow);
 
     content::WebContents* web_contents_;
 
@@ -165,8 +166,8 @@ class DownloadRequestLimiter
     // callbacks.
     std::vector<DownloadRequestLimiter::Callback> callbacks_;
 
-    // Used to remove observers installed on NavigationController.
-    content::NotificationRegistrar registrar_;
+    ScopedObserver<HostContentSettingsMap, content_settings::Observer>
+        observer_;
 
     // Weak pointer factory for generating a weak pointer to pass to the
     // infobar.  User responses to the throttling prompt will be returned