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

Source/modules/speech/SpeechRecognitionResult.cpp

Index: Source/modules/speech/SpeechRecognitionResult.cpp
diff --git a/Source/modules/speech/SpeechRecognitionResult.cpp b/Source/modules/speech/SpeechRecognitionResult.cpp
index ce592a58db0bc2f214582d2d4e501fc7c46434fe..e27c0aba865a7cfc5d81e90495c9f65d840b22aa 100644
--- a/Source/modules/speech/SpeechRecognitionResult.cpp
+++ b/Source/modules/speech/SpeechRecognitionResult.cpp
@@ -34,7 +34,7 @@ SpeechRecognitionResult* SpeechRecognitionResult::create(const HeapVector<Member
     return new SpeechRecognitionResult(alternatives, final);
 }
 
-SpeechRecognitionAlternative* SpeechRecognitionResult::item(unsigned long index)
+SpeechRecognitionAlternative* SpeechRecognitionResult::item(unsigned index)
 {
     if (index >= m_alternatives.size())
         return 0;