Fixed namespace declaration not being cleared between files.

Change-Id: Ie9fedf894d82a403d0b6b4848d221d6bbee58984
Tested: on OS X.
diff --git a/src/idl_parser.cpp b/src/idl_parser.cpp
index e4d2d94..47e44c8 100644
--- a/src/idl_parser.cpp
+++ b/src/idl_parser.cpp
@@ -713,6 +713,7 @@
     while (token_ != kTokenEof) {
       if (token_ == kTokenNameSpace) {
         Next();
+        name_space_.clear();
         for (;;) {
           name_space_.push_back(attribute_);
           Expect(kTokenIdentifier);