MSE, MS, and any blob URL: Ignore preload 'none' on resource fetching

third_party/WebKit/Source/core/html/HTMLMediaElement.cpp

 /*
  * Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
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  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 1077 matching lines @@
                     attemptLoad = false;
                 }
             }
         }
     }
 
     bool canLoadResource = source.isMediaProviderObject() || canLoadURL(url, contentType);
     if (attemptLoad && canLoadResource) {
         ASSERT(!webMediaPlayer());
 
-        if (effectivePreloadType() == WebMediaPlayer::PreloadNone) {
+        if (!m_mediaSource && effectivePreloadType() == WebMediaPlayer::PreloadNone) {

[philipj_slow, 2016/04/14 12:39:27]

I would like it very much if this matched the behavior of
https://github.com/whatwg/html/pull/1037 even if not done in precisely the same
place. In other words, it'd be nice if MediaStream was also exempted here.

Can you use isObjectOrBlobURL perhaps? That doesn't quite match the spec because
it'll be true even for a bogus blob: URL, but maybe that's a better solution
anyway. If it's a bogus blob: URL the load will just fail quicker.

[wolenetz, 2016/04/21 21:37:30]

I've added isObjectOrBlobURL usage here, but adding a related MediaStream layout
test is interesting: it looks like that would best be done in the
web-platform-tests repo, and then imported into Blink the way other media-stream
imported tests are. I'll put together such a wpt test PR shortly and eventual
import of it should hopefully satisfy the mediastream portion of this CR
question.

I've added an invalid blob url non-MSE/non-MS test with preload=none into this
CL.

             WTF_LOG(Media, "HTMLMediaElement::loadResource(%p) : Delaying load because preload == 'none'", this);
             deferLoad();
         } else {
             startPlayerLoad();
         }
     } else {
         mediaLoadingFailed(WebMediaPlayer::NetworkStateFormatError);
     }
 
     // If there is no poster to display, allow the media engine to render video frames as soon as
@@ skipping 2831 matching lines @@
 }
 
 #if !ENABLE(OILPAN)
 WeakPtr<HTMLMediaElement> HTMLMediaElement::createWeakPtr()
 {
     return m_weakPtrFactory.createWeakPtr();
 }
 #endif
 
 } // namespace blink