Modify ThreadChecker and NonThreadSafe so that their functionality is

net/disk_cache/block_files.h

Index: net/disk_cache/block_files.h
diff --git a/net/disk_cache/block_files.h b/net/disk_cache/block_files.h
index d677ba3a14b602ddc9963630e1e542aa7db67bcf..b2c38cd63d5f1c015f2d477d1721dc512edc7b92 100644
--- a/net/disk_cache/block_files.h
+++ b/net/disk_cache/block_files.h
@@ -13,13 +13,10 @@
 #include "base/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/scoped_ptr.h"
+#include "base/threading/thread_checker.h"
 #include "net/disk_cache/addr.h"
 #include "net/disk_cache/mapped_file.h"
 
-namespace base {
-class ThreadChecker;

[brettw, 2011/03/03 17:39:43]

It kind of sucks we lose the ability to forward declare this, especially in some
of these common files like ipc_channel.h. What if you make ThreadChecker derive
from the Impl one so it can still be forward declared?

-}
-
 namespace disk_cache {
 
 // This class handles the set of block-files open by the disk cache.