Revert 169577 "[HTML Import] Let script block by pending resourc..."

Revert 169577 "[HTML Import] Let script block by pending resourc..."

This is a speculative revert to address reported crashes in the wild.

> [HTML Import] Let script block by pending resources created by lifecycle callback
> 
> This change tells the HTML parser know that lifecycle callbacks,
> that is triggered through Microtask checkpoint, can create resources that
> blocks scripts.
> 
> It also streamlines the unblock notification from Document to the parser
> into didLoadAllScriptBlockingResources(). Now both didRemoveAllPendingStylesheets()
> and didLoadAllImports() checks resource readiness and invokes the unified notification.
> 
> TEST=custom-element-style-block.html
> BUG=346408
> R=dglazkov@chromium.org, dominicc@chromium.org
> 
> Review URL: https://codereview.chromium.org/202813002

TBR=morrita@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=169769

[Hajime Morrita, 2014-03-21 20:56:04]

Committed patchset #1 manually as r169769.