Allow setting a new MinidumpDescriptor on ExceptionHandler, also expose directory from MinidumpDescriptor

R=digit at https://breakpad.appspot.com/452003/

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1037 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/client/linux/handler/exception_handler.h

@@ -138,6 +138,10 @@ class ExceptionHandler {
     return minidump_descriptor_;
   }
 
+  void set_minidump_descriptor(const MinidumpDescriptor& descriptor) {
+    minidump_descriptor_ = descriptor;
+  }
+
   void set_crash_handler(HandlerCallback callback) {
     crash_handler_ = callback;
   }