Add a DOMUI datasource that will handle the net-internals page....

Add a DOMUI datasource that will handle the net-internals page.

Right now it is bound to the temporary URL "chrome://net2", since the frontend is under construction.
(Loading this page right now just shows a dummy HTML page.)

This change is a first step to transitioning the about:net-internals  / about:network pages from C++ to javascript.
Note that the network stuff needs to run on the IO thread, however the DOMUI infrastructure is all set up to run on the UI thread.
I work around this by proxying things back and forth through the IO thread. Hopefully in subsequent iterations this overhead can be removed, by exposing a sort of "IO thread DOMUI".

BUG=37421
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=41791

[Mike Belshe, 2010-03-16 22:14:50]

lgtm

http://codereview.chromium.org/1036001/diff/8001/9004
File chrome/browser/dom_ui/net_internals_ui.cc (right):

http://codereview.chromium.org/1036001/diff/8001/9004#newcode56
chrome/browser/dom_ui/net_internals_ui.cc:56: // it the argument |value|.
nit:  This function will also delete |value|.

http://codereview.chromium.org/1036001/diff/8001/9004#newcode111
chrome/browser/dom_ui/net_internals_ui.cc:111: // Helper that runs |method| with
|arg|, and deletes |arg| on completion.
nit:  I find it a little strange that it deletes arg.  Seems like the caller
should do that.  But I see what you are doing with passing across threads.

http://codereview.chromium.org/1036001/diff/8001/9004#newcode257
chrome/browser/dom_ui/net_internals_ui.cc:257: // TODO(eroman): Register with
network stack to observer events.
nit: observer -> observe  (also in next function)

[eroman, 2010-03-16 23:15:58]

http://codereview.chromium.org/1036001/diff/8001/9004
File chrome/browser/dom_ui/net_internals_ui.cc (right):

http://codereview.chromium.org/1036001/diff/8001/9004#newcode56
chrome/browser/dom_ui/net_internals_ui.cc:56: // it the argument |value|.
On 2010/03/16 22:14:50, Mike Belshe wrote:
> nit:  This function will also delete |value|.

Where do you see that? |value| should not be deleted by this function...

http://codereview.chromium.org/1036001/diff/8001/9004#newcode111
chrome/browser/dom_ui/net_internals_ui.cc:111: // Helper that runs |method| with
|arg|, and deletes |arg| on completion.
On 2010/03/16 22:14:50, Mike Belshe wrote:
> nit:  I find it a little strange that it deletes arg.  Seems like the caller
> should do that.  But I see what you are doing with passing across threads.

Yeah, it is yucky.

I wanted to avoid copying too many times, so I make a deep copy on the UI
thread, pass it off to the IO thread, and then delete it here on the IO thread
after the message handler has run. I try to hide those bits in a couple
functions, so each new message handler added doesn't need to think about
deletion (that is why I do the delete here rather than in the specific handler).

Hopefully this UI-->IO layer can be collapsed in the future and this ugly part
goes away.

http://codereview.chromium.org/1036001/diff/8001/9004#newcode257
chrome/browser/dom_ui/net_internals_ui.cc:257: // TODO(eroman): Register with
network stack to observer events.
On 2010/03/16 22:14:50, Mike Belshe wrote:
> nit: observer -> observe  (also in next function)

D'oh! fixed.

[Mike Belshe, 2010-03-17 07:05:08]

http://codereview.chromium.org/1036001/diff/8001/9004
File chrome/browser/dom_ui/net_internals_ui.cc (right):

http://codereview.chromium.org/1036001/diff/8001/9004#newcode56
chrome/browser/dom_ui/net_internals_ui.cc:56: // it the argument |value|.
You're right - I was looking at the wrong instance of CallJavascriptFunction.

On 2010/03/16 23:15:58, eroman wrote:
> On 2010/03/16 22:14:50, Mike Belshe wrote:
> > nit:  This function will also delete |value|.
> 
> Where do you see that? |value| should not be deleted by this function...