Assert that thread-safe reference counting is used with

cross-thread NewRunnableMethod.

This assertion caught such an error in VisitedLinkMaster!

My approach, modify RunnableMethodTraits<T> to assert that
when ReleaseCallee happens on a different thread from
RetainCallee that the type supports thread-safe reference
counting.  I do this by adding a static method to both
RefCounted<T> and RefCountedThreadSafe<T>.

This results in a little ugliness in cases where people
implement AddRef and Release by hand (to make the no-ops).
There may be a nicer way to deal with those few cases.

R=brettw
BUG=none
TEST=none

Review URL: http://codereview.chromium.org/251012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@27379 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 1 insertions, 10 deletions

diff --git a/chrome/browser/printing/print_job.h b/chrome/browser/printing/print_job.h
index 45d5d12..cf4badc 100644
--- a/chrome/browser/printing/print_job.h
+++ b/chrome/browser/printing/print_job.h
@@ -8,7 +8,6 @@
 #include "base/basictypes.h"
 #include "base/gfx/native_widget_types.h"
 #include "base/message_loop.h"
-#include "base/ref_counted.h"
 #include "chrome/browser/printing/print_job_worker_owner.h"
 #include "chrome/common/notification_registrar.h"
 
@@ -32,9 +31,8 @@ class PrinterQuery;
 // any state change. While printing, the PrintJobManager instance keeps a
 // reference to the job to be sure it is kept alive. All the code in this class
 // runs in the UI thread.
-class PrintJob : public base::RefCountedThreadSafe<PrintJob>,
+class PrintJob : public PrintJobWorkerOwner,
                  public NotificationObserver,
-                 public PrintJobWorkerOwner,
                  public MessageLoop::DestructionObserver {
  public:
   // Create a empty PrintJob. When initializing with this constructor,
@@ -52,13 +50,6 @@ class PrintJob : public base::RefCountedThreadSafe<PrintJob>,
                        const NotificationDetails& details);
 
   // PrintJobWorkerOwner
-  virtual void AddRef() {
-    return base::RefCountedThreadSafe<PrintJob>::AddRef();
-  }
-  virtual void Release() {
-    return base::RefCountedThreadSafe<PrintJob>::Release();
-  }
-
   virtual void GetSettingsDone(const PrintSettings& new_settings,
                                PrintingContext::Result result);
   virtual PrintJobWorker* DetachWorker(PrintJobWorkerOwner* new_owner);