PNaCl cleanup: Simplify error checking when opening temp files

components/nacl/renderer/plugin/temporary_file.h

Index: components/nacl/renderer/plugin/temporary_file.h
diff --git a/components/nacl/renderer/plugin/temporary_file.h b/components/nacl/renderer/plugin/temporary_file.h
index fe496f4daa6f8f028ef64b2ba85f4598a69337af..f0669c0a4a096591648a111ef90223e4d2d72326 100644
--- a/components/nacl/renderer/plugin/temporary_file.h
+++ b/components/nacl/renderer/plugin/temporary_file.h
@@ -42,7 +42,7 @@ class TempFile {
   TempFile(Plugin* plugin, PP_FileHandle handle);
   ~TempFile();
 
-  int32_t CheckValidity();
+  bool IsValid() { return file_handle_.IsValid(); }
   // Resets file position of the handle, for reuse.
   bool Reset();