Update MediaKeySession method names to latest EME spec.

public/platform/WebContentDecryptionModuleSession.h

Index: public/platform/WebContentDecryptionModuleSession.h
diff --git a/public/platform/WebContentDecryptionModuleSession.h b/public/platform/WebContentDecryptionModuleSession.h
index 4b01c4f14ec0a770b9b9874bf0631ebea26a9ec5..bf28c7b76ef41bef55081667d7d25f71029e3eed 100644
--- a/public/platform/WebContentDecryptionModuleSession.h
+++ b/public/platform/WebContentDecryptionModuleSession.h
@@ -58,9 +58,9 @@ public:
     virtual ~WebContentDecryptionModuleSession();
 
     virtual WebString sessionId() const = 0;
-    virtual void generateKeyRequest(const WebString& mimeType, const unsigned char* initData, size_t initDataLength) = 0;
-    virtual void update(const unsigned char* key, size_t keyLength) = 0;
-    virtual void close() = 0;
+    virtual void initialize(const WebString& mimeType, const unsigned char* initData, size_t initDataLength) = 0;
+    virtual void update(const unsigned char* response, size_t responseLength) = 0;
+    virtual void release() = 0;
 };
 
 } // namespace blink