Make DownloadHistory observe manager, items

content/public/browser/download_item.h

Index: content/public/browser/download_item.h
diff --git a/content/public/browser/download_item.h b/content/public/browser/download_item.h
index 20dc06b715698c8fbd5dd31d42c2fa39996bc22d..aecf44021af3e897d2dea0eb7b8004340b6ffa5c 100644
--- a/content/public/browser/download_item.h
+++ b/content/public/browser/download_item.h
@@ -23,6 +23,7 @@
 
 #include "base/file_path.h"
 #include "base/string16.h"
+#include "base/supports_user_data.h"
 #include "content/public/browser/download_danger_type.h"
 #include "content/public/browser/download_interrupt_reasons.h"
 #include "content/public/common/page_transition_types.h"
@@ -49,7 +50,7 @@ struct DownloadPersistentStoreInfo;
 // Destination tab's download view, may refer to a given DownloadItem.
 //
 // This is intended to be used only on the UI thread.
-class CONTENT_EXPORT DownloadItem {
+class CONTENT_EXPORT DownloadItem : public base::SupportsUserData {
  public:
   enum DownloadState {
     // Download is actively progressing.
@@ -61,10 +62,6 @@ class CONTENT_EXPORT DownloadItem {
     // Download has been cancelled.
     CANCELLED,
 
-    // This state indicates that the download item is about to be destroyed,
-    // and observers seeing this state should release all references.
-    REMOVING,
-
     // This state indicates that the download has been interrupted.
     INTERRUPTED,
 
@@ -102,22 +99,23 @@ class CONTENT_EXPORT DownloadItem {
   // to receive updates to the download's status.
   class CONTENT_EXPORT Observer {
    public:
-    virtual void OnDownloadUpdated(DownloadItem* download) = 0;
+    virtual void OnDownloadUpdated(DownloadItem* download) {}
 
     // Called when a downloaded file has been opened.
-    virtual void OnDownloadOpened(DownloadItem* download) = 0;
+    virtual void OnDownloadOpened(DownloadItem* download) {}
+
+    // Called when the user removes a download.
+    virtual void OnDownloadRemoved(DownloadItem* download) {}
+
+    // Called when the download is being destroyed. This happens after
+    // every OnDownloadRemoved() as well as when the DownloadManager is going
+    // down.
+    virtual void OnDownloadDestroyed(DownloadItem* download) {}
 
    protected:
     virtual ~Observer() {}
   };
 
-  // Interface for data that can be stored associated with (and owned
-  // by) an object of this class via GetExternalData/SetExternalData.
-  class ExternalData {
-   public:
-    virtual ~ExternalData() {};
-  };
-
   virtual ~DownloadItem() {}
 
   virtual void AddObserver(DownloadItem::Observer* observer) = 0;
@@ -225,8 +223,6 @@ class CONTENT_EXPORT DownloadItem {
   // true.
   virtual void OnContentCheckCompleted(DownloadDangerType danger_type) = 0;
 
-  virtual bool IsPersisted() const = 0;
-
   // Accessors
   virtual const std::string& GetHash() const = 0;
   virtual DownloadState GetState() const = 0;
@@ -247,7 +243,6 @@ class CONTENT_EXPORT DownloadItem {
   virtual DownloadId GetGlobalId() const = 0;
   virtual base::Time GetStartTime() const = 0;
   virtual base::Time GetEndTime() const = 0;
-  virtual int64 GetDbHandle() const = 0;
   virtual bool IsPaused() const = 0;
   virtual bool GetOpenWhenComplete() const = 0;
   virtual void SetOpenWhenComplete(bool open) = 0;
@@ -272,7 +267,6 @@ class CONTENT_EXPORT DownloadItem {
   virtual const std::string& GetETag() const = 0;
 
   virtual DownloadInterruptReason GetLastReason() const = 0;
-  virtual DownloadPersistentStoreInfo GetPersistentStoreInfo() const = 0;
   virtual BrowserContext* GetBrowserContext() const = 0;
   virtual WebContents* GetWebContents() const = 0;
 
@@ -291,22 +285,6 @@ class CONTENT_EXPORT DownloadItem {
   // but does not for dangerous downloads until the name is verified.
   virtual FilePath GetUserVerifiedFilePath() const = 0;
 
-  // Manage data owned by other subsystems associated with the
-  // DownloadItem.  By custom, key is the address of a
-  // static char subsystem_specific_string[] = ".."; defined
-  // in the subsystem, but the only requirement of this interface
-  // is that the key be unique over all data stored with this
-  // DownloadItem.
-  //
-  // Note that SetExternalData takes ownership of the
-  // passed object; it will be destroyed when the DownloadItem is.
-  // If an object is already held by the DownloadItem associated with
-  // the passed key, it will be destroyed if overwriten by a new pointer
-  // (overwrites by the same pointer are ignored).
-  virtual       ExternalData* GetExternalData(const void* key) = 0;
-  virtual const ExternalData* GetExternalData(const void* key) const = 0;
-  virtual void SetExternalData(const void* key, ExternalData* data) = 0;
-
   virtual std::string DebugString(bool verbose) const = 0;
 
   virtual void MockDownloadOpenForTesting() = 0;