Force preload=none and disable autoplay on lowend Android devices.

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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 1985 matching lines @@
 void HTMLMediaElement::setPreload(const AtomicString& preload)
 {
     BLINK_MEDIA_LOG << "setPreload(" << (void*)this << ", " << preload << ")";
     setAttribute(preloadAttr, preload);
 }
 
 WebMediaPlayer::Preload HTMLMediaElement::preloadType() const
 {
     // Force preload to none for cellular connections or when data saver is explicitly set.
     if (networkStateNotifier().isCellularConnectionType()
-        || (document().settings() && document().settings()->dataSaverEnabled())) {
+        || (document().settings() && (document().settings()->dataSaverEnabled() || document().settings()->forcePreloadNoneForMediaElements()))) {

[foolip, 2016/09/19 13:58:54]

Makes sense, as long as it's OK that calling play() or seeking will start the
load.

[DaleCurtis, 2016/09/19 21:04:46]

Yes, this is fine since it's still relatively protected by a user gesture. When
we enabled Spitzer we brought in some automatic preload which is too much for
these devices, so this restores us to the pre-Spitzer state where the user has
to shoot themselves in their own foot instead of us doing it for them!

Still not great, but there's no guarantee with these older devices (even force
pausing and releasing the resources of the media is insufficient when the device
is in a near oom state).

         UseCounter::count(document(), UseCounter::HTMLMediaElementPreloadForcedNone);
         return WebMediaPlayer::PreloadNone;
     }
 
     const AtomicString& preload = fastGetAttribute(preloadAttr);
     if (equalIgnoringCase(preload, "none")) {
         UseCounter::count(document(), UseCounter::HTMLMediaElementPreloadNone);
         return WebMediaPlayer::PreloadNone;
     }
     if (equalIgnoringCase(preload, "metadata")) {
@@ skipping 2010 matching lines @@
 
 IntRect HTMLMediaElement::AutoplayHelperClientImpl::absoluteBoundingBoxRect() const
 {
     IntRect result;
     if (LayoutObject* object = m_element->layoutObject())
         result = object->absoluteBoundingBoxRect();
     return result;
 }
 
 } // namespace blink