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

Source/modules/speech/SpeechGrammarList.h

Index: Source/modules/speech/SpeechGrammarList.h
diff --git a/Source/modules/speech/SpeechGrammarList.h b/Source/modules/speech/SpeechGrammarList.h
index 01632099b5f746860c967c5b18a0d8a26bcb34b4..97da574a93569014f8edfd8a355a79c1d15554c2 100644
--- a/Source/modules/speech/SpeechGrammarList.h
+++ b/Source/modules/speech/SpeechGrammarList.h
@@ -39,8 +39,8 @@ class SpeechGrammarList final : public GarbageCollected<SpeechGrammarList>, publ
 public:
     static SpeechGrammarList* create();
 
-    unsigned long length() const { return m_grammars.size(); }
-    SpeechGrammar* item(unsigned long) const;
+    unsigned length() const { return m_grammars.size(); }
+    SpeechGrammar* item(unsigned) const;
 
     void addFromUri(ExecutionContext*, const String& src, double weight = 1.0);
     void addFromString(const String&, double weight = 1.0);