PrerenderManager is no longer refcounted.

The PrerenderManager should be destroyed on the UI thread, along with
the PrerenderContents that it owns.

I originally did this by using the DeleteOnUIThread trait, but this
leaked PrerenderManager's during browser shutdown, since the last
reference was held by an object on the IO thread, and the DeleteTask
was never processed.

Now, the Profile owns the PrerenderManager's lifetime. All other
references to the PrerenderManager are weak references. With the
current thread-safety restrictions of WeakPtr's, this means that the
presence of a PrererenderManager can not be checked on the IO thread,
so all LOAD_PREFETCH requests will have a PrerenderResourceHandler
constructed, regardless of whether the current profile supports
prerendering.

BUG=77930
TEST=Existing unit tests and browser tests.


Review URL: http://codereview.chromium.org/6877085

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@82669 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 4 insertions, 3 deletions

diff --git a/chrome/browser/net/net_pref_observer.h b/chrome/browser/net/net_pref_observer.h
index a03129e..d023572 100644
--- a/chrome/browser/net/net_pref_observer.h
+++ b/chrome/browser/net/net_pref_observer.h
@@ -23,8 +23,9 @@ class PrerenderManager;
 // Must be used only on the UI thread.
 class NetPrefObserver : public NotificationObserver {
  public:
-  // |prefs| must outlive this NetPrefObserver. A reference is
-  // held to |prerender_manager| if it is non-NULL.
+  // |prefs| must be non-NULL and |*prefs| must outlive this.
+  // |prerender_manager| may be NULL. If not, |*prerender_manager| must
+  // outlive this.
   NetPrefObserver(PrefService* prefs,
                   prerender::PrerenderManager* prerender_manager);
   ~NetPrefObserver();
@@ -43,7 +44,7 @@ class NetPrefObserver : public NotificationObserver {
   BooleanPrefMember network_prediction_enabled_;
   BooleanPrefMember spdy_disabled_;
   BooleanPrefMember http_throttling_enabled_;
-  scoped_refptr<prerender::PrerenderManager> prerender_manager_;
+  prerender::PrerenderManager* prerender_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(NetPrefObserver);
 };