Reland: Remove "needkey" event and add its replacement, "encrypted".

Source/web/WebMediaPlayerClientImpl.h

Index: Source/web/WebMediaPlayerClientImpl.h
diff --git a/Source/web/WebMediaPlayerClientImpl.h b/Source/web/WebMediaPlayerClientImpl.h
index e34aa888f3c1cde0126788a3812318b74ae82073..0ff81e912109bd7191861027f308cd32899a41ac 100644
--- a/Source/web/WebMediaPlayerClientImpl.h
+++ b/Source/web/WebMediaPlayerClientImpl.h
@@ -70,7 +70,9 @@ public:
     virtual void keyAdded(const WebString& keySystem, const WebString& sessionId) override;
     virtual void keyError(const WebString& keySystem, const WebString& sessionId, MediaKeyErrorCode, unsigned short systemCode) override;
     virtual void keyMessage(const WebString& keySystem, const WebString& sessionId, const unsigned char* message, unsigned messageLength, const WebURL& defaultURL) override;
+    // FIXME: Remove keyNeeded() once rename to encrypted() is complete.
     virtual void keyNeeded(const WebString& contentType, const unsigned char* initData, unsigned initDataLength) override;
+    virtual void encrypted(const WebString& initDataType, const unsigned char* initData, unsigned initDataLength) override;
 
     virtual void setWebLayer(WebLayer*) override;
     virtual WebMediaPlayer::TrackId addAudioTrack(const WebString& id, AudioTrackKind, const WebString& label, const WebString& language, bool enabled) override;