Only delete old frames when a new main frame navigation commits

chrome/browser/extensions/api/web_navigation/frame_navigation_state.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_EXTENSIONS_API_WEB_NAVIGATION_FRAME_NAVIGATION_STATE_H_
 #define CHROME_BROWSER_EXTENSIONS_API_WEB_NAVIGATION_FRAME_NAVIGATION_STATE_H_
 
 #include <map>
 #include <set>
 
 #include "base/compiler_specific.h"
 #include "googleurl/src/gurl.h"
 
+namespace content {
+class RenderViewHost;
+}
+
 namespace extensions {
 
 // Tracks the navigation state of all frames in a given tab currently known to
 // the webNavigation API. It is mainly used to track in which frames an error
 // occurred so no further events for this frame are being sent.
 class FrameNavigationState {
  public:
-  // A frame is uniquely identified by its frame ID and the render process ID.
-  // We use the render process ID instead of e.g. a pointer to the RVH so we
-  // don't depend on the lifetime of the RVH.
+  // A frame is uniquely identified by its frame ID and the RVH it's in.
   struct FrameID {
     FrameID();
-    FrameID(int64 frame_num, int render_process_id);
+    FrameID(int64 frame_num, content::RenderViewHost* render_view_host);
 
     bool IsValid() const;
 
     bool operator<(const FrameID& other) const;
     bool operator==(const FrameID& other) const;
     bool operator!=(const FrameID& other) const;
 
     int64 frame_num;
-    int render_process_id;
+    content::RenderViewHost* render_view_host;

[Matt Perry, 2012/07/30 11:52:43]

Is render_view_host guaranteed to outlive a FrameID? The webnavigation API seems
to be assuming that it will always get the final navigation event for all RVHs.
Maybe you should listen to RENDER_VIEW_HOST_DESTROYED as well, to be safe.

[jochen (gone - plz use gerrit), 2012/07/30 15:33:18]

Done.

   };
   typedef std::set<FrameID>::const_iterator const_iterator;
 
   FrameNavigationState();
   ~FrameNavigationState();
 
   // Use these to iterate over all frame IDs known by this object.
   const_iterator begin() const { return frame_ids_.begin(); }
   const_iterator end() const { return frame_ids_.end(); }
 
   // True if navigation events for the given frame can be sent.
   bool CanSendEvents(FrameID frame_id) const;
 
   // True if in general webNavigation events may be sent for the given URL.
   bool IsValidUrl(const GURL& url) const;
 
   // Starts to track a frame identified by its |frame_id| showing the URL |url|.
   void TrackFrame(FrameID frame_id,
                   const GURL& url,
                   bool is_main_frame,
                   bool is_error_page);
 
+  // Stops tracking all frames for a given RenderViewHost.
+  void StopTrackingFramesInRVH(content::RenderViewHost* render_view_host);
+
   // Update the URL associated with a given frame.
   void UpdateFrame(FrameID frame_id, const GURL& url);
 
   // Returns true if |frame_id| is a known frame.
   bool IsValidFrame(FrameID frame_id) const;
 
   // Returns the URL corresponding to a tracked frame given by its |frame_id|.
   GURL GetUrl(FrameID frame_id) const;
 
-  // True if the frame given by its |frame_id| is the main frame of its tab.
+  // True if the frame given by its |frame_id| is a main frame of its tab.
+  // There might be multiple uncomitted main frames.
   bool IsMainFrame(FrameID frame_id) const;
 
-  // Returns the frame ID of the main frame, or -1 if the frame ID is not
-  // known.
+  // Returns the frame ID of the last comitted main frame, or -1 if the frame
+  // ID is not known.
   FrameID GetMainFrameID() const;
 
   // Marks a frame as in an error state, i.e. the onErrorOccurred event was
   // fired for this frame, and no further events should be sent for it.
   void SetErrorOccurredInFrame(FrameID frame_id);
 
   // True if the frame is marked as being in an error state.
   bool GetErrorOccurredInFrame(FrameID frame_id) const;
 
   // Marks a frame as having finished its last navigation, i.e. the onCompleted
@@ skipping 32 matching lines @@
     GURL url;  // URL of this frame.
   };
   typedef std::map<FrameID, FrameState> FrameIdToStateMap;
 
   // Tracks the state of known frames.
   FrameIdToStateMap frame_state_map_;
 
   // Set of all known frames.
   std::set<FrameID> frame_ids_;
 
-  // The current main frame.
+  // The id of the last comitted main frame.
   FrameID main_frame_id_;
 
   // If true, also allow events from chrome-extension:// URLs.
   static bool allow_extension_scheme_;
 
   DISALLOW_COPY_AND_ASSIGN(FrameNavigationState);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_WEB_NAVIGATION_FRAME_NAVIGATION_STATE_H_