Fix dtor of web_contents.

Fix dtor of web_contents.

BUG=NONE
TEST=run_tests
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=182313

[achuithb, 2013-02-13 09:03:12]

Disconnect needs to be in WebContents.

[nduca, 2013-02-13 09:08:39]

are we missing a unit test that would have revealed this issue sooner?

lgtm if you feel our test coverage is adequate

[achuithb, 2013-02-13 09:48:26]

On 2013/02/13 09:08:39, nduca wrote:
> are we missing a unit test that would have revealed this issue sooner?
> 
> lgtm if you feel our test coverage is adequate

We're not testing WebContents independently of Tabs. We should probably have
some unittests just for WebContents.

[achuithb, 2013-02-13 09:54:30]

I've added a TODO to move some of the Tab unittests to WebContents...

[nduca, 2013-02-13 10:04:55]

But what was the failure here? Extensions were calling disconnect when we quit? 

Why didnt' the extension unitttest catch this?

[achuithb, 2013-02-13 10:08:10]

Failure is that ExtensionPage does not disconnect on destruction (since
WebContent does not disconnect on destruction), so you're unable to create the
ExtensionPage a second time. 

This failure will be caught by the extension unittests, but that's a bit
indirect.

[nduca, 2013-02-13 10:32:34]

We should have a test that explicitly disconnects the extension. YOu could add
that here.

E.g. 


another test in the SingleTextensionTests class that you made that disconnects
the extension.

[achuithb, 2013-02-13 10:41:40]

On 2013/02/13 10:32:34, nduca wrote:
> We should have a test that explicitly disconnects the extension. YOu could add
> that here.
> 
> E.g. 
> 
> 
> another test in the SingleTextensionTests class that you made that disconnects
> the extension.

I don't quite understand. 

Something like:
extension = b.extensions[load_extension]
extension.Disconnect()

Now test that extension.ExecuteJavaScript throws an exception?

[nduca, 2013-02-13 10:43:44]

That looks good. But do something with the extension that causes a backend to be
connected, eg exec javascript. Add 1+1. Put a comment explaining why. You're
trying to make sure connect gets called, and remember, the first thing web
contents when you do something on the tab is it connects its backend.

[nduca, 2013-02-13 10:44:27]

And no, dont test that executejs throws an exception!

The test is that Disconnect worked.

If you had tested disconnect before, then you would have discovered that it
didnt' exist.

[achuithb, 2013-02-13 10:49:59]

On 2013/02/13 10:44:27, nduca wrote:
> And no, dont test that executejs throws an exception!
> 
> The test is that Disconnect worked.
> 
> If you had tested disconnect before, then you would have discovered that it
> didnt' exist.

Done.