Disk cache: Reference CL for the implementation of file format version 3.

net/disk_cache/file_win.cc

Index: net/disk_cache/file_win.cc
===================================================================
--- net/disk_cache/file_win.cc	(revision 199883)
+++ net/disk_cache/file_win.cc	(working copy)
@@ -44,7 +44,6 @@
   if (error) {
     DCHECK(!actual_bytes);
     actual_bytes = static_cast<DWORD>(net::ERR_CACHE_READ_FAILURE);
-    NOTREACHED();
   }
 
   if (data->callback_)
@@ -67,7 +66,10 @@
 namespace disk_cache {
 
 File::File(base::PlatformFile file)
-    : init_(true), mixed_(true), platform_file_(INVALID_HANDLE_VALUE),
+    : init_(true),
+      mixed_(true),
+      force_creation_(false),
+      platform_file_(INVALID_HANDLE_VALUE),
       sync_platform_file_(file) {
 }
 
@@ -78,8 +80,9 @@
 
   DWORD sharing = FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE;
   DWORD access = GENERIC_READ | GENERIC_WRITE | DELETE;
+  DWORD mode = force_creation_ ? OPEN_ALWAYS : OPEN_EXISTING;
   platform_file_ = CreateFile(name.value().c_str(), access, sharing, NULL,
-                              OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
+                              mode, FILE_FLAG_OVERLAPPED, NULL);
 
   if (INVALID_HANDLE_VALUE == platform_file_)
     return false;