Remove RenderFrameHostImplState and convert it to boolean.

content/browser/frame_host/render_frame_host_impl.h

 // Copyright 2013 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 CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_HOST_IMPL_H_
 #define CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_HOST_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 85 matching lines @@
 struct ResourceResponse;
 
 class CONTENT_EXPORT RenderFrameHostImpl : public RenderFrameHost,
                                            public BrowserAccessibilityDelegate,
                                            public SiteInstanceImpl::Observer {
  public:
   using AXTreeSnapshotCallback =
       base::Callback<void(
           const ui::AXTreeUpdate&)>;
 
-  // Keeps track of the state of the RenderFrameHostImpl, particularly with
-  // respect to swap out.
-  enum RenderFrameHostImplState {
-    // The standard state for a RFH handling the communication with an active
-    // RenderFrame.
-    STATE_DEFAULT = 0,
-    // The RFH has not received the SwapOutACK yet, but the new page has
-    // committed in a different RFH.  Upon reception of the SwapOutACK, the RFH
-    // will be deleted.
-    STATE_PENDING_SWAP_OUT,
-  };
-  // Helper function to determine whether the RFH state should contribute to the
-  // number of active frames of a SiteInstance or not.
-  static bool IsRFHStateActive(RenderFrameHostImplState rfh_state);
-
   // An accessibility reset is only allowed to prevent very rare corner cases
   // or race conditions where the browser and renderer get out of sync. If
   // this happens more than this many times, kill the renderer.
   static const int kMaxAccessibilityResets = 5;
 
   static RenderFrameHostImpl* FromID(int process_id, int routing_id);
   static RenderFrameHostImpl* FromAXTreeID(
       AXTreeIDRegistry::AXTreeID ax_tree_id);
 
   ~RenderFrameHostImpl() override;
@@ skipping 221 matching lines @@
     return is_waiting_for_beforeunload_ack_;
   }
 
   // Whether the RFH is waiting for an unload ACK from the renderer.
   bool IsWaitingForUnloadACK() const;
 
   // Called when either the SwapOut request has been acknowledged or has timed
   // out.
   void OnSwappedOut();
 
-  // The current state of this RFH.
-  RenderFrameHostImplState rfh_state() const { return rfh_state_; }
+  // This method returns true from the time this RenderFrameHost has been
+  // created. It returns false, once SwapOut is called and the object is pending
+  // deletion.

[Charlie Reis, 2016/04/08 20:25:37]

Just some wordsmithing:

This method returns true from the time this RenderFrameHost is created until
SwapOut is called, at which point it is pending deletion.

[nasko, 2016/04/08 21:25:32]

Done.

+  bool is_active() { return !is_waiting_for_swapout_ack_; }
 
   // Sends the given navigation message. Use this rather than sending it
   // yourself since this does the internal bookkeeping described below. This
   // function takes ownership of the provided message pointer.
   //
   // If a cross-site request is in progress, we may be suspended while waiting
   // for the onbeforeunload handler, so this function might buffer the message
   // rather than sending it.
   void Navigate(const CommonNavigationParams& common_params,
                 const StartNavigationParams& start_params,
@@ skipping 303 matching lines @@
       const std::set<std::string>& digests_of_uris_of_serialized_resources);
 
 #if defined(OS_MACOSX) || defined(OS_ANDROID)
   void OnShowPopup(const FrameHostMsg_ShowPopup_Params& params);
   void OnHidePopup();
 #endif
 
   // Registers Mojo services that this frame host makes available.
   void RegisterMojoServices();
 
-  // Updates the state of this RenderFrameHost and clears any waiting state
-  // that is no longer relevant.
-  void SetState(RenderFrameHostImplState rfh_state);
+  // Resets any waiting state of this RenderFrameHost that is no longer
+  // relevant.
+  void ResetWaitingState();
 
   // Returns whether the given URL is allowed to commit in the current process.
   // This is a more conservative check than RenderProcessHost::FilterURL, since
   // it will be used to kill processes that commit unauthorized URLs.
   bool CanCommitURL(const GURL& url);
 
   // Returns whether the given origin is allowed to commit in the current
   // RenderFrameHost. The |url| is used to ensure it matches the origin in cases
   // where it is applicable. This is a more conservative check than
   // RenderProcessHost::FilterURL, since it will be used to kill processes that
@@ skipping 123 matching lines @@
   // RenderFrameHosts that need management of the rendering and input events
   // for their frame subtrees require RenderWidgetHosts. This typically
   // means frames that are rendered in different processes from their parent
   // frames.
   // TODO(kenrb): Later this will also be used on the top-level frame, when
   // RenderFrameHost owns its RenderViewHost.
   RenderWidgetHostImpl* render_widget_host_;
 
   int routing_id_;
 
-  // The current state of this RenderFrameHost.
-  RenderFrameHostImplState rfh_state_;
+  // Boolean indicating whether this RenderFrameHost is being actively used or
+  // is waiting for FrameHostMsg_SwapOut_ACK and thus pending deletion.
+  bool is_waiting_for_swapout_ack_;
 
   // Tracks whether the RenderFrame for this RenderFrameHost has been created in
   // the renderer process.  Currently only used for subframes.
   // TODO(creis): Use this for main frames as well when RVH goes away.
   bool render_frame_created_;
 
   // Whether we should buffer outgoing Navigate messages rather than sending
   // them. This will be true when a RenderFrameHost is created for a cross-site
   // request, until we hear back from the onbeforeunload handler of the old
   // RenderFrameHost.
@@ skipping 131 matching lines @@
 
   // NOTE: This must be the last member.
   base::WeakPtrFactory<RenderFrameHostImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderFrameHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_HOST_IMPL_H_