Fix crashes in DownloadRequestLimiter when extension popups/bubbles initiate downloads automatically

chrome/browser/download/download_request_limiter.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_DOWNLOAD_DOWNLOAD_REQUEST_LIMITER_H_
 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_REQUEST_LIMITER_H_
 #pragma once
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
+#include "content/public/browser/web_contents_observer.h"
 
 class DownloadRequestInfoBarDelegate;
 class TabContentsWrapper;
 
 namespace content {
 class NavigationController;
 class WebContents;
 }
 
 // DownloadRequestLimiter is responsible for determining whether a download
@@ skipping 33 matching lines @@
   static const size_t kMaxDownloadsAtOnce = 50;
 
   // The callback from CanDownloadOnIOThread. This is invoked on the io thread.
   // The boolean parameter indicates whether or not the download is allowed.
   typedef base::Callback<void(bool /*allow*/)> Callback;
 
   // TabDownloadState maintains the download state for a particular tab.
   // TabDownloadState prompts the user with an infobar as necessary.
   // TabDownloadState deletes itself (by invoking
   // DownloadRequestLimiter::Remove) as necessary.
-  class TabDownloadState : public content::NotificationObserver {
+  class TabDownloadState : public content::NotificationObserver,
+                           public content::WebContentsObserver {
    public:
     // Creates a new TabDownloadState. |controller| is the controller the
     // TabDownloadState tracks the state of and is the host for any dialogs that
     // are displayed. |originating_controller| is used to determine the host of
     // the initial download. If |originating_controller| is null, |controller|
     // is used. |originating_controller| is typically null, but differs from
     // |controller| in the case of a constrained popup requesting the download.
     TabDownloadState(DownloadRequestLimiter* host,
-                     content::NavigationController* controller,
-                     content::NavigationController* originating_controller);
+                     content::WebContents* web_contents,
+                     content::WebContents* originating_web_contents);
     virtual ~TabDownloadState();
 
     // Status of the download.
     void set_download_status(DownloadRequestLimiter::DownloadStatus status) {
       status_ = status;
     }
     DownloadRequestLimiter::DownloadStatus download_status() const {
       return status_;
     }
 
     // Number of "ALLOWED" downloads.
     void increment_download_count() {
       download_count_++;
     }
     size_t download_count() const {
       return download_count_;
     }
 
+    content::WebContents* web_contents() {
+      return content::WebContentsObserver::web_contents();

[Randy Smith (Not in Mondays), 2012/05/25 18:52:34]

This made me do a double take.  Maybe worth a comment?  "Promoting protected
method to public" or something like that?

[benjhayden, 2012/05/25 20:41:17]

Done.

+    }
+
+    // content::WebContentsObserver overrides.
     // Invoked when a user gesture occurs (mouse click, enter or space). This
     // may result in invoking Remove on DownloadRequestLimiter.
-    void OnUserGesture();
+    virtual void DidGetUserGesture() OVERRIDE;
 
     // Asks the user if they really want to allow the download.
     // See description above CanDownloadOnIOThread for details on lifetime of
     // callback.
     void PromptUserForDownload(
         content::WebContents* tab,
         const DownloadRequestLimiter::Callback& callback);
 
     // Are we showing a prompt to the user?
     bool is_showing_prompt() const { return (infobar_ != NULL); }
 
-    // NavigationController we're tracking.
-    content::NavigationController* controller() const { return controller_; }
-
     // Invoked from DownloadRequestDialogDelegate. Notifies the delegates and
     // changes the status appropriately. Virtual for testing.
     virtual void Cancel();
     virtual void Accept();
 
    protected:
     // Used for testing.
     TabDownloadState()
         : host_(NULL),
-          controller_(NULL),
           status_(DownloadRequestLimiter::ALLOW_ONE_DOWNLOAD),
           download_count_(0),
           infobar_(NULL) {
     }
 
    private:
     // content::NotificationObserver method.
     virtual void Observe(int type,
                          const content::NotificationSource& source,
                          const content::NotificationDetails& details) OVERRIDE;
 
     // Notifies the callbacks as to whether the download is allowed or not.
     // Updates status_ appropriately.
     void NotifyCallbacks(bool allow);
 
     DownloadRequestLimiter* host_;
 
-    content::NavigationController* controller_;
-
     // Host of the first page the download started on. This may be empty.
     std::string initial_page_host_;
 
     DownloadRequestLimiter::DownloadStatus status_;
 
     size_t download_count_;
 
     // Callbacks we need to notify. This is only non-empty if we're showing a
     // dialog.
     // See description above CanDownloadOnIOThread for details on lifetime of
@@ skipping 16 matching lines @@
   DownloadStatus GetDownloadStatus(content::WebContents* tab);
 
   // Updates the state of the page as necessary and notifies the callback.
   // WARNING: both this call and the callback are invoked on the io thread.
   void CanDownloadOnIOThread(int render_process_host_id,
                              int render_view_id,
                              int request_id,
                              const std::string& request_method,
                              const Callback& callback);
 
-  // Invoked when the user presses the mouse, enter key or space bar. This may
-  // change the download status for the page. See the class description for
-  // details.
-  void OnUserGesture(content::WebContents* tab);
-
  private:
   FRIEND_TEST_ALL_PREFIXES(DownloadTest, DownloadResourceThrottleCancels);
   friend class base::RefCountedThreadSafe<DownloadRequestLimiter>;
   friend class DownloadRequestLimiterTest;
   friend class TabDownloadState;
 
   ~DownloadRequestLimiter();
 
   // For unit tests. If non-null this is used instead of creating a dialog.
   class TestingDelegate {
    public:
     virtual bool ShouldAllowDownload() = 0;
 
    protected:
     virtual ~TestingDelegate() {}
   };
   static void SetTestingDelegate(TestingDelegate* delegate);
 
   // Gets the download state for the specified controller. If the
   // TabDownloadState does not exist and |create| is true, one is created.
   // See TabDownloadState's constructor description for details on the two
   // controllers.
   //
   // The returned TabDownloadState is owned by the DownloadRequestLimiter and
   // deleted when no longer needed (the Remove method is invoked).
   TabDownloadState* GetDownloadState(
-      content::NavigationController* controller,
-      content::NavigationController* originating_controller,
+      content::WebContents* web_contents,
+      content::WebContents* originating_web_contents,
       bool create);
 
   // CanDownloadOnIOThread invokes this on the UI thread. This determines the
   // tab and invokes CanDownloadImpl.
   void CanDownload(int render_process_host_id,
                    int render_view_id,
                    int request_id,
                    const std::string& request_method,
                    const Callback& callback);
 
   // Does the work of updating the download status on the UI thread and
   // potentially prompting the user.
-  void CanDownloadImpl(TabContentsWrapper* originating_tab,
+  void CanDownloadImpl(content::WebContents* originating_contents,
                        int request_id,
                        const std::string& request_method,
                        const Callback& callback);
 
   // Invoked on the UI thread. Schedules a call to NotifyCallback on the io
   // thread.
   void ScheduleNotification(const Callback& callback, bool allow);
 
   // Removes the specified TabDownloadState from the internal map and deletes
   // it. This has the effect of resetting the status for the tab to
   // ALLOW_ONE_DOWNLOAD.
   void Remove(TabDownloadState* state);
 
   // Maps from tab to download state. The download state for a tab only exists
   // if the state is other than ALLOW_ONE_DOWNLOAD. Similarly once the state
   // transitions from anything but ALLOW_ONE_DOWNLOAD back to ALLOW_ONE_DOWNLOAD
   // the TabDownloadState is removed and deleted (by way of Remove).
-  typedef std::map<content::NavigationController*, TabDownloadState*> StateMap;
+  typedef std::map<content::WebContents*, TabDownloadState*> StateMap;
   StateMap state_map_;
 
   static TestingDelegate* delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadRequestLimiter);
 };
 
 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_REQUEST_LIMITER_H_