Make HTMLMediaElement.setMediaKeys() asynchronous.

Source/web/WebMediaPlayerClientImpl.cpp

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "web/WebMediaPlayerClientImpl.h"
 
 #include "core/frame/LocalFrame.h"
 #include "core/html/HTMLMediaElement.h"
 #include "core/html/TimeRanges.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/compositing/RenderLayerCompositor.h"
 #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"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/GraphicsLayer.h"
 #include "platform/graphics/gpu/Extensions3DUtil.h"
 #include "platform/graphics/skia/GaneshUtils.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebAudioSourceProvider.h"
 #include "public/platform/WebCString.h"
@@ skipping 19 matching lines @@
 #endif
 
 
 #include "wtf/Assertions.h"
 #include "wtf/text/CString.h"
 
 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);
 
     if (!webFrame || !webFrame->client())
         return nullptr;
     return adoptPtr(webFrame->client()->createMediaPlayer(webFrame, url, client));
 }
 
 WebMediaPlayer* WebMediaPlayerClientImpl::webMediaPlayer() const
@@ skipping 148 matching lines @@
 #endif
 
     m_webMediaPlayer->setVolume(mediaElement().playerVolume());
 
     m_webMediaPlayer->setPoster(poster);
 
 #if OS(ANDROID)
     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);
 }
 
 
 void WebMediaPlayerClientImpl::paint(GraphicsContext* context, const IntRect& rect)
 {
     // Normally GraphicsContext operations do nothing when painting is disabled.
     // Since we're accessing platformContext() directly we have to manually
     // check.
     if (m_webMediaPlayer && !context->paintingDisabled()) {
@@ skipping 141 matching lines @@
 
 void WebMediaPlayerClientImpl::AudioClientImpl::setFormat(size_t numberOfChannels, float sampleRate)
 {
     if (m_client)
         m_client->setFormat(numberOfChannels, sampleRate);
 }
 
 #endif
 
 } // namespace blink