Remove bad const from disk_cache::Backend interface.

net/http/mock_http_cache.h

Index: net/http/mock_http_cache.h
diff --git a/net/http/mock_http_cache.h b/net/http/mock_http_cache.h
index fa4fb54a1866a35248f4957ea904a3b96ed54b58..dcf7e3d3c22c63ebd65a52c7a8e24f0c209bfc5a 100644
--- a/net/http/mock_http_cache.h
+++ b/net/http/mock_http_cache.h
@@ -106,11 +106,11 @@ class MockDiskCache : public disk_cache::Backend {
                         const net::CompletionCallback& callback) OVERRIDE;
   virtual int DoomAllEntries(const net::CompletionCallback& callback) OVERRIDE;
   virtual int DoomEntriesBetween(
-      const base::Time initial_time,
-      const base::Time end_time,
+      base::Time initial_time,
+      base::Time end_time,
       const net::CompletionCallback& callback) OVERRIDE;
   virtual int DoomEntriesSince(
-      const base::Time initial_time,
+      base::Time initial_time,
       const net::CompletionCallback& callback) OVERRIDE;
   virtual int OpenNextEntry(void** iter, disk_cache::Entry** next_entry,
                             const net::CompletionCallback& callback) OVERRIDE;