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

Source/modules/speech/SpeechRecognition.cpp

Index: Source/modules/speech/SpeechRecognition.cpp
diff --git a/Source/modules/speech/SpeechRecognition.cpp b/Source/modules/speech/SpeechRecognition.cpp
index 16d59af59a4ab2b0494dc03378537b5f4fdb0121..8c75608abf642428172fa0006362efa1359f3965 100644
--- a/Source/modules/speech/SpeechRecognition.cpp
+++ b/Source/modules/speech/SpeechRecognition.cpp
@@ -108,7 +108,7 @@ void SpeechRecognition::didEndAudio()
 
 void SpeechRecognition::didReceiveResults(const HeapVector<Member<SpeechRecognitionResult> >& newFinalResults, const HeapVector<Member<SpeechRecognitionResult> >& currentInterimResults)
 {
-    unsigned long resultIndex = m_finalResults.size();
+    size_t resultIndex = m_finalResults.size();
 
     for (size_t i = 0; i < newFinalResults.size(); ++i)
         m_finalResults.append(newFinalResults[i]);