HTML Imports: Make sure new imports being added to the "first child"

HTML Imports: Make sure new imports being added to the "first child"

The notion of first child was introduced at r171966. That is,
The first import of import-tree order should take care of all
the subimports of the same URL.

This invariant is enforced by HTMLImportLoader::addImport()
but its implementation wasn't enough. This change extends it
so that the invariant enforcement is done against the subtree,
instead of just against the added node itself.

TEST=import-normalize-[123]{3}.html
R=dominicc@chromium.org,dglazkov@chromium.org
BUG=372055
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=173900

[Hajime Morrita, 2014-05-11 02:24:18]

Could you rubberstamp/review please?
I have to merge this to the fresh branch.

[dglazkov, 2014-05-12 17:32:36]

lgtm

https://codereview.chromium.org/274213003/diff/40001/Source/core/html/imports...
File Source/core/html/imports/HTMLImportChild.cpp (right):

https://codereview.chromium.org/274213003/diff/40001/Source/core/html/imports...
Source/core/html/imports/HTMLImportChild.cpp:220: void
HTMLImportChild::normalize()
I apologize, I am trying to (re)learn how this works.

normalize() is invoked in addImport, which itself comes from createLoader or
shareLoader, which in turn comes from ensureLoader. This is where I get lost.
The ensureLoader is called in several places, and all of them have to do with
loading completion or start.

I am not sure I understand why. Can't the ordering be ensured at the time the
link is processed? Please help me understand :)

[commit-bot: I haz the power, 2014-05-12 17:32:55]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/morrita@chromium.org/274213003/40001

[commit-bot: I haz the power, 2014-05-12 18:08:43]

Change committed as 173900

[Hajime Morrita, 2014-05-14 08:17:22]

On 2014/05/12 17:32:36, dglazkov wrote:
> lgtm
> 
>
https://codereview.chromium.org/274213003/diff/40001/Source/core/html/imports...
> File Source/core/html/imports/HTMLImportChild.cpp (right):
> 
>
https://codereview.chromium.org/274213003/diff/40001/Source/core/html/imports...
> Source/core/html/imports/HTMLImportChild.cpp:220: void
> HTMLImportChild::normalize()
> I apologize, I am trying to (re)learn how this works.
> 
> normalize() is invoked in addImport, which itself comes from createLoader or
> shareLoader, which in turn comes from ensureLoader. This is where I get lost.
> The ensureLoader is called in several places, and all of them have to do with
> loading completion or start.
>
> I am not sure I understand why. Can't the ordering be ensured at the time the
> link is processed? Please help me understand :)

This is where I should revise for clarify.
The ensureLoader() is called when each HTMLImportChild is created and added into
import tree.
It used to be created lazily for a reason but no longer is. I'll make a cleanup
change.