Navigation transitions: Added "addStyleSheetByURL" function to insert stylesheet links.

Navigation transitions: Added "addStyleSheetByURL" function to insert stylesheet links.

If transition-entering-stylesheet is defined in the response headers for the incoming document, this stylesheet will be applied as the incoming document is shown.

This is the blink side of the CL.

Design doc: https://docs.google.com/a/chromium.org/document/d/17jg1RRL3RI969cLwbKBIcoGDsPwqaEdBxafGNYGwiY4/edit# 
Implementation details: https://docs.google.com/a/chromium.org/document/d/1kREPtFJaeLoDKwrfmrYTD7DHCdxX1RzFBga2gNY8lyE/edit#heading=h.bng2kpmyvxq5 
BUG=370696
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=174470

[shatch, 2014-05-14 18:11:59]

Hi Adam, cutting up transitions change into bunch of cls, ptal.

[shatch, 2014-05-19 19:12:56]

Hi Eric, since Adam is out, do you mind taking a look?

[eseidel, 2014-05-20 23:03:42]

Is this just a convenience function?  I would presume one could do this already
by just executing javascript in the page.

[shatch, 2014-05-20 23:10:39]

On 2014/05/20 23:03:42, eseidel wrote:
> Is this just a convenience function?  I would presume one could do this
already
> by just executing javascript in the page.

Yeah, just a convenience function, bulk of the work will be done on the chrome
side. The stylesheet urls will be parsed out of the response headers from the
incoming page, passed to the TransitionPageHelper, which will hold on to them
until the transition content view is navigated and showing the serialized
elements, then add them to the transition page.

[eseidel, 2014-05-21 00:44:19]

lgtm

:shrug:.  I'm not sure this is worth pushing into the Blink API, but OK.

[commit-bot: I haz the power, 2014-05-21 00:44:53]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/simonhatch@chromium.org/285623003/20001

[commit-bot: I haz the power, 2014-05-21 20:30:30]

Change committed as 174470