Disk Cache: Add more corruption tracking histograms.

net/disk_cache/backend_impl.cc

Index: net/disk_cache/backend_impl.cc
===================================================================
--- net/disk_cache/backend_impl.cc	(revision 133063)
+++ net/disk_cache/backend_impl.cc	(working copy)
@@ -447,6 +447,9 @@
     return net::ERR_FAILED;
   }
 
+  if (create_files || !data_->header.num_entries)
+    ReportError(ERR_CACHE_CREATED);
+
   if (!(user_flags_ & kNoRandom) &&
       cache_type_ == net::DISK_CACHE && !InitExperiment(&data_->header))
     return net::ERR_FAILED;
@@ -484,6 +487,9 @@
 
   disabled_ = !rankings_.Init(this, new_eviction_);
 
+  if (!disabled_ && !(user_flags_ & kNoRandom) && base::RandInt(0, 99) < 2)
+    rankings_.SelfCheck();  // Ignore return value for now.
+
 #if defined(STRESS_CACHE_EXTENDED_VALIDATION)
   trace_object_->EnableTracing(false);
   int sc = SelfCheck();
@@ -1548,8 +1554,7 @@
 
   STRESS_DCHECK(block_files_.IsValid(address));
 
-  if (!address.is_initialized() || address.is_separate_file() ||
-      address.file_type() != BLOCK_256) {
+  if (!address.SanityCheckForEntry()) {
     LOG(WARNING) << "Wrong entry address.";
     STRESS_NOTREACHED();
     return ERR_INVALID_ADDRESS;