Make HTMLMediaElement.setMediaKeys() asynchronous.

Source/web/WebMediaPlayerClientImpl.cpp

Index: Source/web/WebMediaPlayerClientImpl.cpp
diff --git a/Source/web/WebMediaPlayerClientImpl.cpp b/Source/web/WebMediaPlayerClientImpl.cpp
index 059913134535b8455caaea8df1bcf90ab41cfbb8..4c14d9297659519459081c63e17c05d2ec995cd7 100644
--- a/Source/web/WebMediaPlayerClientImpl.cpp
+++ b/Source/web/WebMediaPlayerClientImpl.cpp
@@ -13,6 +13,7 @@
 #include "modules/encryptedmedia/HTMLMediaElementEncryptedMedia.h"
 #include "modules/encryptedmedia/MediaKeyNeededEvent.h"
 #include "modules/mediastream/MediaStreamRegistry.h"
+#include "platform/ContentDecryptionModuleResult.h"
 #include "platform/audio/AudioBus.h"
 #include "platform/audio/AudioSourceProviderClient.h"
 #include "platform/geometry/IntSize.h"
@@ -52,6 +53,19 @@ using namespace blink;
 
 namespace blink {
 
+// Represents the result used when setContentDecryptionModule() is called.
+// This happens asynchronously. Since there is no way to report an error,

[ddorwin, 2014/07/31 00:56:36]

This is the scenario xhwang was referring to in the other CL.
Maybe we should DCHECK that it doesn't fail.

[jrummell, 2014/08/07 01:43:02]

Remove this in favor of having a synchronous method.

+// simply ignore any result.
+class IgnoreResponseContentDecryptionModuleResult FINAL : public ContentDecryptionModuleResult {

[ddorwin, 2014/07/31 00:56:36]

We should come up with a better name, especially if we make changes related to
the comments above and below.

[jrummell, 2014/08/07 01:43:02]

Gone.

+public:
+    IgnoreResponseContentDecryptionModuleResult() { }
+
+    // ContentDecryptionModuleResult implementation.
+    virtual void complete() OVERRIDE { }
+    virtual void completeWithSession(blink::WebContentDecryptionModuleResult::SessionStatus status) OVERRIDE { }
+    virtual void completeWithError(blink::WebContentDecryptionModuleException code, unsigned long systemCode, const blink::WebString& message) OVERRIDE { }
+};
+
 static PassOwnPtr<WebMediaPlayer> createWebMediaPlayer(WebMediaPlayerClient* client, const WebURL& url, LocalFrame* frame)
 {
     WebLocalFrameImpl* webFrame = WebLocalFrameImpl::fromFrame(frame);
@@ -220,8 +234,10 @@ void WebMediaPlayerClientImpl::load(WebMediaPlayer::LoadType loadType, const WTF
     m_usePaintOnAndroid = (loadType != WebMediaPlayer::LoadTypeMediaStream);
 #endif
 
-    // Tell WebMediaPlayer about any connected CDM (may be null).
-    m_webMediaPlayer->setContentDecryptionModule(HTMLMediaElementEncryptedMedia::contentDecryptionModule(mediaElement()));
+    // Tell WebMediaPlayer about any connected CDM (may be null). Ignore any
+    // errors that happen while setting the CDM.
+    ContentDecryptionModuleResult* result = new IgnoreResponseContentDecryptionModuleResult();
+    m_webMediaPlayer->setContentDecryptionModule(HTMLMediaElementEncryptedMedia::contentDecryptionModule(mediaElement()), result->result());

[ddorwin, 2014/07/31 00:56:36]

Hmm, I wonder if this needs to be synchronous due to the load call that follows.
They at least need to be serialized.

Maybe the new Result class above should call load() in complete(). That would be
the safest solution. HOWEVER, load() is probably expected to be synchronous, so
we might need to block here or something. Hmm.

Alternatively, maybe we should keep (and rename) the synchronous version of
setContentDecryptionModule for this very scenario.

[jrummell, 2014/08/07 01:43:02]

Done.

     m_webMediaPlayer->load(loadType, kurl, corsMode);
 }