create a separate WebMediaPlayer for URL derived from media stream

content/renderer/render_view_impl.cc

 // Copyright (c) 2012 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 "content/renderer/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 #include <string>
 #include <vector>
@@ skipping 174 matching lines @@
 #include "webkit/glue/alt_error_page_resource_fetcher.h"
 #include "webkit/glue/dom_operations.h"
 #include "webkit/glue/glue_serialize.h"
 #include "webkit/glue/web_intent_service_data.h"
 #include "webkit/glue/webdropdata.h"
 #include "webkit/glue/webkit_constants.h"
 #include "webkit/glue/webkit_glue.h"
 #include "webkit/glue/weburlresponse_extradata_impl.h"
 #include "webkit/gpu/webgraphicscontext3d_in_process_impl.h"
 #include "webkit/media/webmediaplayer_impl.h"
+#include "webkit/media/webmediaplayer_ms.h"
 #include "webkit/plugins/npapi/plugin_list.h"
 #include "webkit/plugins/npapi/webplugin_delegate.h"
 #include "webkit/plugins/npapi/webplugin_delegate_impl.h"
 #include "webkit/plugins/npapi/webplugin_impl.h"
 #include "webkit/plugins/ppapi/ppapi_webplugin_impl.h"
 
 #if defined(OS_ANDROID)
 #include "content/common/android/device_info.h"
 #include "content/renderer/android/address_detector.h"
 #include "content/renderer/android/content_detector.h"
@@ skipping 2284 matching lines @@
     audio_source_provider = new RenderAudioSourceProvider();
 
     // Add the chrome specific audio renderer, using audio_source_provider
     // as the sink.
     media::AudioRendererImpl* audio_renderer =
         new media::AudioRendererImpl(audio_source_provider);
     collection->AddAudioRenderer(audio_renderer);
   }
 
   WebGraphicsContext3DCommandBufferImpl* context3d = NULL;
-  if (!CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kDisableAcceleratedVideoDecode))
+  if (!cmd_line->HasSwitch(switches::kDisableAcceleratedVideoDecode))
     context3d = RenderThreadImpl::current()->GetGpuVDAContext3D();
   if (context3d) {
     scoped_refptr<base::MessageLoopProxy> factories_loop =
         RenderThreadImpl::current()->compositor_thread() ?
         RenderThreadImpl::current()->compositor_thread()->GetWebThread()
             ->message_loop()->message_loop_proxy() :
         base::MessageLoopProxy::current();
     GpuChannelHost* gpu_channel_host =
         RenderThreadImpl::current()->EstablishGpuChannelSync(
             content::CAUSE_FOR_GPU_LAUNCH_VIDEODECODEACCELERATOR_INITIALIZE);
     collection->GetVideoDecoders()->push_back(new media::GpuVideoDecoder(
         base::Bind(&media::MessageLoopFactory::GetMessageLoop,
                    base::Unretained(message_loop_factory),
                    media::MessageLoopFactory::kDecoder),
         factories_loop,
         new RendererGpuVideoDecoderFactories(
             gpu_channel_host, factories_loop, context3d)));
   }
 
   WebMediaPlayer* media_player =
       content::GetContentClient()->renderer()->OverrideCreateWebMediaPlayer(
           this, frame, client, AsWeakPtr(), collection, audio_source_provider,
           audio_source_provider, message_loop_factory, media_stream_impl_,
           render_media_log);
   if (!media_player) {
+    EnsureMediaStreamImpl();

[piman, 2012/09/22 01:03:37]

This looks heavy the first time (e.g. it creates a thread), but we'll pay that
cost even if the flag isn't set / it's not a media stream url.
Looking at IsMediaStream, it looks like it doesn't need anything from
MediaStreamImpl and could be implemented as a static method, so that you could
do this only the first time you need to create a WebMediaPlayerMS. WDYT?

[wjia(left Chromium), 2012/09/22 17:04:42]

That's a good point. In MediaStreamImpl, IsMediaStream doesn't need anything
from MediaStreamImpl. However, it uses GetMediaStream which is a virtual
function for test purpose
(http://code.google.com/p/chromium/source/search?q=getmediastream&origq=getmed...).
The unit test (in media_stream_impl_unittest.cc) has a different implementation
of GetMediaStream and it uses some member. It will be some refactoring effort to
make IsStreamMedia static. Could we do it in a follow-up patch?

For now, I changed the condition checking a bit so that it won't affect chrome
performance when the flag is not on.

+    if (cmd_line->HasSwitch(switches::kEnableWebMediaPlayerMS) &&
+        media_stream_impl_ && media_stream_impl_->IsMediaStream(url)) {
+      // TODO(wjia): when all patches related to WebMediaPlayerMS have been
+      // landed, remove the switch. Refer to crbug.com/142988.
+      return new webkit_media::WebMediaPlayerMS(
+          frame, client, AsWeakPtr(), media_stream_impl_, render_media_log);
+    }
+
     media_player = new webkit_media::WebMediaPlayerImpl(
         frame, client, AsWeakPtr(), collection, audio_source_provider,
         audio_source_provider, message_loop_factory, media_stream_impl_,
         render_media_log);
   }
   return media_player;
 }
 
 WebApplicationCacheHost* RenderViewImpl::createApplicationCacheHost(
     WebFrame* frame, WebApplicationCacheHostClient* client) {
@@ skipping 3583 matching lines @@
 
   updating_frame_tree_ = true;
   active_frame_id_map_.clear();
 
   target_process_id_ = process_id;
   target_routing_id_ = route_id;
   CreateFrameTree(webview()->mainFrame(), frames);
 
   updating_frame_tree_ = false;
 }