Add PNACL_CACHE cache backend type, and allow larger files for this type.

chrome/browser/nacl_host/pnacl_translation_cache.cc

Index: chrome/browser/nacl_host/pnacl_translation_cache.cc
diff --git a/chrome/browser/nacl_host/pnacl_translation_cache.cc b/chrome/browser/nacl_host/pnacl_translation_cache.cc
index 278e89a9d3858b132705621c0b360e74ea44bc0a..e3c8c207cbb429c29bd1b40e2d6a2dd62fee2922 100644
--- a/chrome/browser/nacl_host/pnacl_translation_cache.cc
+++ b/chrome/browser/nacl_host/pnacl_translation_cache.cc
@@ -372,7 +372,7 @@ void PnaclTranslationCache::GetNexe(const std::string& key,
 int PnaclTranslationCache::InitOnDisk(const base::FilePath& cache_directory,
                                       const CompletionCallback& callback) {
   in_memory_ = false;
-  return Init(net::DISK_CACHE, cache_directory, 0 /* auto size */, callback);
+  return Init(net::PNACL_CACHE, cache_directory, 0 /* auto size */, callback);
 }
 
 int PnaclTranslationCache::InitInMemory(const CompletionCallback& callback) {