GDB: Test for executing nacl-manifest command twice.

tests/gdb/gdb_test.py

Index: tests/gdb/gdb_test.py
===================================================================
--- tests/gdb/gdb_test.py	(revision 10609)
+++ tests/gdb/gdb_test.py	(working copy)
@@ -247,17 +247,21 @@
   def Eval(self, expression):
     return self.Command('-data-evaluate-expression ' + expression)['value']
 
+  def LoadManifestFile(self):
+    assert self._manifest_file is not None
+    # gdb uses bash-like escaping which removes slashes from Windows paths.
+    self.Command('nacl-manifest ' + FilenameToUnix(self._manifest_file))
+
   def Connect(self):
     self._GetResponse()
     if self._options.irt is not None:
       self.Command('nacl-irt ' + FilenameToUnix(self._options.irt))
     if self._options.ld_so is not None:
-      # gdb uses bash-like escaping which removes slashes from Windows paths.
-      manifest_file = GenerateManifest(self._options.output_dir,
-                                       self._options.nexe,
-                                       self._options.ld_so,
-                                       self._name)
-      self.Command('nacl-manifest ' + FilenameToUnix(manifest_file))
+      self._manifest_file = GenerateManifest(self._options.output_dir,
+                                             self._options.nexe,
+                                             self._options.ld_so,
+                                             self._name)
+      self.LoadManifestFile()
       self.Command('set breakpoint pending on')
     else:
       self.Command('file ' + FilenameToUnix(self._options.nexe))