Handle interface to prerenders.

chrome/browser/prerender/prerender_contents.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_PRERENDER_PRERENDER_CONTENTS_H_
 #define CHROME_BROWSER_PRERENDER_PRERENDER_CONTENTS_H_
 #pragma once
 
 #include <list>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/time.h"
 #include "base/values.h"
 #include "chrome/browser/prerender/prerender_final_status.h"
+#include "chrome/browser/prerender/prerender_handle.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/common/referrer.h"
 #include "ui/gfx/size.h"
 
 class Profile;
 class TabContents;
 struct FaviconURL;
 
@@ skipping 31 matching lines @@
         Profile* profile,
         const GURL& url,
         const content::Referrer& referrer,
         Origin origin,
         uint8 experiment_id) = 0;
 
    private:
     DISALLOW_COPY_AND_ASSIGN(Factory);
   };
 
-  // Information on pages that the prerendered page has tried to prerender.
-  struct PendingPrerenderInfo;
-  typedef std::list<PendingPrerenderInfo> PendingPrerenderList;
-
   // Indicates how this PrerenderContents relates to MatchComplete. This is to
   // figure out which histograms to use to record the FinalStatus, Match (record
   // all prerenders and control group prerenders) or MatchComplete (record
   // running prerenders only in the way they would have been recorded in the
   // control group).
   enum MatchCompleteStatus {
     // A regular prerender which will be recorded both in Match and
     // MatchComplete.
     MATCH_COMPLETE_DEFAULT,
     // A prerender that used to be a regular prerender, but has since been
-    // replaced by a MatchComplete dummy.  Therefore, we will record this only
+    // replaced by a MatchComplete dummy. Therefore, we will record this only
     // for Match, but not for MatchComplete.
     MATCH_COMPLETE_REPLACED,
     // A prerender that is a MatchComplete dummy replacing a regular prerender.
     // In the control group, our prerender never would have been canceled, so
     // we record in MatchComplete but not Match.
     MATCH_COMPLETE_REPLACEMENT,
     // A prerender that is a MatchComplete dummy, early in the process of being
     // created. This prerender should not fail. Record for MatchComplete, but
     // not Match.
     MATCH_COMPLETE_REPLACEMENT_PENDING,
   };
 
   virtual ~PrerenderContents();
 
+  // For MatchComplete correctness, create a dummy replacement prerender
+  // contents to stand in for this prerender contents that (which we are about
+  // to destroy).
+  void MakeIntoDummyReplacementOf(

[dominich, 2012/06/28 00:34:32]

can this be a separate CL?

+      const PrerenderContents* original_prerender_contents);
+
   bool Init();
 
   static Factory* CreateFactory();
 
   // Start rendering the contents in the prerendered state. If
   // |is_control_group| is true, this will go through some of the mechanics of
   // starting a prerender, without actually creating the RenderView.
   // |creator_child_id| is the id of the child process that caused the prerender
   // to be created, and is needed so that the prerendered URLs can be sent to it
   // so render-initiated navigations will swap in the prerendered page. |size|
@@ skipping 38 matching lines @@
 
   // Set the final status for how the PrerenderContents was used. This
   // should only be called once, and should be called before the prerender
   // contents are destroyed.
   void set_final_status(FinalStatus final_status);
   FinalStatus final_status() const { return final_status_; }
 
   Origin origin() const { return origin_; }
   uint8 experiment_id() const { return experiment_id_; }
 
+  int client_count() const { return client_count_; }

[dominich, 2012/06/28 00:34:32]

usage count? instance count?

+  void IncrementClientCount();
+  void DecrementClientCount();
+
   base::TimeTicks load_start_time() const { return load_start_time_; }
 
   // Indicates whether this prerendered page can be used for the provided
   // URL, i.e. whether there is a match. |matching_url| is optional and will be
   // set to the URL that is found as a match if it is provided.
   // TODO(gavinp,mmenke): Rework matching to be based on both the URL
   // and the session WebStorage.
-  bool MatchesURL(const GURL& url, GURL* matching_url) const;
+  bool Matches(

[dominich, 2012/06/28 00:34:32]

we didn't use the returned matching_url anywhere? if not, then change the
comment please.

+      const GURL& url,
+      const content::SessionStorageNamespace* session_storage_namespace);
 
   // content::WebContentsObserver implementation.
   virtual void DidStopLoading() OVERRIDE;
   virtual void DidStartProvisionalLoadForFrame(
       int64 frame_id,
       bool is_main_frame,
       const GURL& validated_url,
       bool is_error_page,
       content::RenderViewHost* render_view_host) OVERRIDE;
   virtual void DidFinishLoad(int64 frame_id,
@@ skipping 31 matching lines @@
   // new tab.
   void CommitHistory(TabContents* tab);
 
   base::Value* GetAsValue() const;
 
   // Returns whether a pending cross-site navigation is happening.
   // This could happen with renderer-issued navigations, such as a
   // MouseEvent being dispatched by a link to a website installed as an app.
   bool IsCrossSiteNavigationPending() const;
 
-  // Adds a pending prerender to the list.
-  virtual void AddPendingPrerender(const GURL& url,
-                                   const content::Referrer& referrer,
-                                   const gfx::Size& size);
+  virtual PrerenderHandle AddPendingPrerender(const GURL& url,
+                                              const content::Referrer& referrer,
+                                              const gfx::Size& size);
 
   // Returns true if |url| corresponds to a pending prerender.

[dominich, 2012/06/28 00:34:32]

comment

-  bool IsPendingEntry(const GURL& url) const;
+  bool IsPendingEntry(PrerenderHandle prerender_handle) const;
 
   // Reissues any pending prerender requests from the prerendered page.  Also
   // clears the list of pending requests.
   void StartPendingPrerenders();
 
  protected:
+  // Information on pages that the prerendered page has tried to prerender.
+  struct PendingPrerenderInfo {

[dominich, 2012/06/28 00:34:32]

I believe this can just be a forward reference here, and then actually defined
in the .cc file as before.

If not, why not?

+    PendingPrerenderInfo(PrerenderHandleImpl* prerender_handle_impl,
+                         const GURL& url,
+                         const content::Referrer& referrer,
+                         const gfx::Size& size);
+
+    PrerenderHandleImpl* prerender_handle_impl;

[dominich, 2012/06/28 00:34:32]

const PrerenderHandleImpl?

+    const GURL url;
+    const content::Referrer referrer;
+    const gfx::Size size;
+  };
+  typedef std::list<PendingPrerenderInfo> PendingPrerenderList;
+

[dominich, 2012/06/28 00:34:32]

nit: extra blank line

+
   PrerenderContents(PrerenderManager* prerender_manager,
                     PrerenderTracker* prerender_tracker,
                     Profile* profile,
                     const GURL& url,
                     const content::Referrer& referrer,
                     Origin origin,
                     uint8 experiment_id);
 
   // Called whenever a RenderViewHost is created for prerendering.  Only called
   // once the RenderViewHost has a RenderView and RenderWidgetHostView.
@@ skipping 10 matching lines @@
 
   bool prerendering_has_been_cancelled() const {
     return prerendering_has_been_cancelled_;
   }
 
   virtual content::WebContents* CreateWebContents(
       content::SessionStorageNamespace* session_storage_namespace);
 
   bool prerendering_has_started_;
 
+  // Time at which we started to load the URL.  This is used to compute
+  // the time elapsed from initiating a prerender until the time the
+  // (potentially only partially) prerendered page is shown to the user.
+  base::TimeTicks load_start_time_;
+
  private:
   class TabContentsDelegateImpl;
 
   // Needs to be able to call the constructor.
   friend class PrerenderContentsFactoryImpl;
 
   friend class PrerenderRenderViewHostObserver;
 
   // Message handlers.
   void OnUpdateFaviconURL(int32 page_id, const std::vector<FaviconURL>& urls);
@@ skipping 28 matching lines @@
   int32 page_id_;
   GURL url_;
   GURL icon_url_;
   content::NotificationRegistrar notification_registrar_;
 
   // A vector of URLs that this prerendered page matches against.
   // This array can contain more than element as a result of redirects,
   // such as HTTP redirects or javascript redirects.
   std::vector<GURL> alias_urls_;
 
+  // The session storage namespace for use in Matching. We must save it
+  // rather than get it from the RenderViewHost since in the control group
+  // we won't have a RenderViewHost.
+  content::SessionStorageNamespace* session_storage_namespace_;
+
+  // Number of distinct clients of this prerendered page (distinct link elements

[dominich, 2012/06/28 00:34:32]

instances?

+  // for instance).
+  int client_count_;
+
   bool has_stopped_loading_;
 
   // True when the main frame has finished loading.
   bool has_finished_loading_;
 
   // This must be the same value as the PrerenderTracker has recorded for
   // |this|, when |this| has a RenderView.
   FinalStatus final_status_;
 
   // The MatchComplete status of the prerender, indicating how it relates
   // to being a MatchComplete dummy (see definition of MatchCompleteStatus
   // above).
   MatchCompleteStatus match_complete_status_;
 
   // Tracks whether or not prerendering has been cancelled by calling Destroy.
   // Used solely to prevent double deletion.
   bool prerendering_has_been_cancelled_;
 
-  // Time at which we started to load the URL.  This is used to compute
-  // the time elapsed from initiating a prerender until the time the
-  // (potentially only partially) prerendered page is shown to the user.
-  base::TimeTicks load_start_time_;
-
   // Process Metrics of the render process associated with the
   // RenderViewHost for this object.
   scoped_ptr<base::ProcessMetrics> process_metrics_;
 
   // The prerendered TabContents; may be null.
   scoped_ptr<TabContents> prerender_contents_;
 
   scoped_ptr<PrerenderRenderViewHostObserver> render_view_host_observer_;
 
   scoped_ptr<TabContentsDelegateImpl> tab_contents_delegate_;
@@ skipping 16 matching lines @@
 
   // The size of the WebView from the launching page.
   gfx::Size size_;
 
   DISALLOW_COPY_AND_ASSIGN(PrerenderContents);
 };
 
 }  // namespace prerender
 
 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_CONTENTS_H_