Fix number parsing problems with HttpResponseHeaders::GetAgeValue() to not accept invalid numbers.

net/http/http_response_headers.h

Index: net/http/http_response_headers.h
diff --git a/net/http/http_response_headers.h b/net/http/http_response_headers.h
index a3126aa72d76c45fa1bc9e69fdec9bab0bf72470..c115bee12dc976bf9fd359a6b47cc6710b8a5619 100644
--- a/net/http/http_response_headers.h
+++ b/net/http/http_response_headers.h
@@ -253,8 +253,8 @@ class NET_EXPORT HttpResponseHeaders
                                 const base::Time& current_time) const;
 
   // The following methods extract values from the response headers.  If a
-  // value is not present, then false is returned.  Otherwise, true is returned
-  // and the out param is assigned to the corresponding value.
+  // value is not present, or is invalid, then false is returned.  Otherwise,
+  // true is returned and the out param is assigned to the corresponding value.
   bool GetMaxAgeValue(base::TimeDelta* value) const;
   bool GetAgeValue(base::TimeDelta* value) const;
   bool GetDateValue(base::Time* value) const;