Use "unsigned" rather than "unsigned long" for C++ code interacting with WebIDL's "unsigned long".

Source/modules/speech/SpeechGrammarList.cpp

Index: Source/modules/speech/SpeechGrammarList.cpp
diff --git a/Source/modules/speech/SpeechGrammarList.cpp b/Source/modules/speech/SpeechGrammarList.cpp
index 043412e0102f958d3ea7b9787149130ea644bc02..4eeefa7e3fbafb06cacb74bb01d1b5d3dc0143e9 100644
--- a/Source/modules/speech/SpeechGrammarList.cpp
+++ b/Source/modules/speech/SpeechGrammarList.cpp
@@ -36,7 +36,7 @@ SpeechGrammarList* SpeechGrammarList::create()
     return new SpeechGrammarList;
 }
 
-SpeechGrammar* SpeechGrammarList::item(unsigned long index) const
+SpeechGrammar* SpeechGrammarList::item(unsigned index) const
 {
     if (index >= m_grammars.size())
         return 0;