Add HTMLMediaElement.waitingforkey event

public/platform/WebMediaPlayerClient.h

Index: public/platform/WebMediaPlayerClient.h
diff --git a/public/platform/WebMediaPlayerClient.h b/public/platform/WebMediaPlayerClient.h
index 3403a21e642f7899716ef66b2f5349de52a6990c..ef8af818e77297e05a69e9ee4f5529f2b2be595d 100644
--- a/public/platform/WebMediaPlayerClient.h
+++ b/public/platform/WebMediaPlayerClient.h
@@ -82,6 +82,8 @@ public:
     virtual void keyError(const WebString& keySystem, const WebString& sessionId, MediaKeyErrorCode, unsigned short systemCode) = 0;
     virtual void keyMessage(const WebString& keySystem, const WebString& sessionId, const unsigned char* message, unsigned messageLength, const WebURL& defaultURL) = 0;
     virtual void encrypted(const WebString& initDataType, const unsigned char* initData, unsigned initDataLength) = 0;
+    virtual void waitingForKey() = 0;
+    virtual void noLongerWaitingForKey() = 0;

[dcheng, 2015/02/20 18:19:20]

I feel like these could be better named. In the past, we've tended to use verbs
for method names. It seems WebMediaPlayerClient has diverged from this
convention somewhat, but I think it reads a bit more clearly.

Maybe something like:
WebMediaPlayerClient::waitForKey()
WebMediaPlayerClient::didGetKey()

or something else (I'm sure someone can come up with better names). The reason I
didn't just use the spec verbs is because (to me) it's not clear that wait for
key and resume playback are immediately related.

[sandersd (OOO until July 31), 2015/02/20 20:17:04]

I'm okay with waitingForKey(), because like the other methods here it is named
after the associated event. noLongerWaitingForKey() is harder to justify, but at
least it's clear in context.

[ddorwin, 2015/02/20 21:05:37]

It's definitely not "waitForKey()" because Blink doesn't do any waiting.

These should probably be onFoo or fireFoo, but consistency with the other
methods is higher priority.

noLongerWaitingForKey() is odd, but I can't think of another name that doesn't
expose implementation (i.e. clearWaitingForKeyFlag()).

     virtual void setWebLayer(WebLayer*) = 0;
     virtual WebMediaPlayer::TrackId addAudioTrack(const WebString& id, AudioTrackKind, const WebString& label, const WebString& language, bool enabled) = 0;
     virtual void removeAudioTrack(WebMediaPlayer::TrackId) = 0;