NaCl: enable meta-based validation for shared libraries.

chrome/browser/nacl_host/nacl_browser.h

Index: chrome/browser/nacl_host/nacl_browser.h
diff --git a/chrome/browser/nacl_host/nacl_browser.h b/chrome/browser/nacl_host/nacl_browser.h
index f3d86460119f8565c535869d6d59961091837403..d30af55a7d205f97d3472fb962db5cdc8c71d9c0 100644
--- a/chrome/browser/nacl_host/nacl_browser.h
+++ b/chrome/browser/nacl_host/nacl_browser.h
@@ -6,6 +6,7 @@
 #define CHROME_BROWSER_NACL_HOST_NACL_BROWSER_H_
 
 #include "base/bind.h"
+#include "base/containers/mru_cache.h"
 #include "base/files/file_util_proxy.h"
 #include "base/memory/singleton.h"
 #include "base/memory/weak_ptr.h"
@@ -15,6 +16,15 @@
 class URLPattern;
 class GURL;
 
+namespace nacl {
+
+// Open an immutable executable file that can be mmaped.
+// This function should only be called on a tread that can perform file IO.
+void OpenNaClExecutableImpl(const base::FilePath& file_path,
+                            base::PlatformFile* file);
+
+}
+
 // Represents shared state for all NaClProcessHost objects in the browser.
 class NaClBrowser {
  public:
@@ -70,6 +80,9 @@ class NaClBrowser {
     return validation_cache_.GetValidationCacheKey();
   }
 
+  uint64 PutFilePath(const base::FilePath& path);
+  bool GetFilePath(uint64 nonce, base::FilePath *path);
+
   bool QueryKnownToValidate(const std::string& signature, bool off_the_record);
   void SetKnownToValidate(const std::string& signature, bool off_the_record);
   void ClearValidationCache(const base::Closure& callback);
@@ -123,6 +136,9 @@ class NaClBrowser {
   NaClResourceState validation_cache_state_;
   base::Callback<void(int)> debug_stub_port_listener_;
 
+  typedef base::HashingMRUCache<uint64, base::FilePath> PathCacheType;
+  PathCacheType path_cache_;
+
   bool ok_;
 
   // A list of pending tasks to start NaCl processes.