Add UMA actions for elements on the Hung Renderer Dialog

Add UMA actions for elements on the Hung Renderer Dialog.

This will help us diagnose how often this Dialog is appearing with no associated crash report.

BUG=436379

[Will Harris, 2014-12-22 20:54:24]

wfh@chromium.org changed reviewers:
+ isherman@chromium.org, sky@chromium.org

[Will Harris, 2014-12-22 20:54:56]

PTAL

isherman for actions.xml
sky for everything else

[Will Harris, 2014-12-22 23:06:40]

wfh@chromium.org changed reviewers:
+ mpearson@chromium.org
- isherman@chromium.org

[Will Harris, 2014-12-22 23:07:11]

On 2014/12/22 20:54:56, Will Harris wrote:
> PTAL
> 
> isherman for actions.xml
> sky for everything else

try mpearson instead of isherman.

[Will Harris, 2014-12-30 11:04:45]

On 2014/12/22 23:07:11, Will Harris wrote:
> On 2014/12/22 20:54:56, Will Harris wrote:
> > PTAL
> > 
> > isherman for actions.xml
> > sky for everything else
> 
> try mpearson instead of isherman.

festive ping.

[Mark P, 2015-01-02 18:41:15]

actions.xml lgtm

[Will Harris, 2015-01-02 22:28:50]

wfh@chromium.org changed reviewers:
+ msw@chromium.org

[Will Harris, 2015-01-02 22:29:13]

ping for chrome/browser/ui/views

[msw, 2015-01-02 22:58:35]

https://codereview.chromium.org/819163002/diff/1/chrome/browser/ui/views/hung...
File chrome/browser/ui/views/hung_renderer_view.cc (right):

https://codereview.chromium.org/819163002/diff/1/chrome/browser/ui/views/hung...
chrome/browser/ui/views/hung_renderer_view.cc:288:
content::RecordAction(UserMetricsAction("HungRendererDialogView.Shown"));
Should this be outside of the active Widget check? (Do you want to record this
metric if the dialog is triggered while it's already open, perhaps if a second
tab is hung?)

Further, should this be before the early return at the top of the function? (Do
you want to record this metric if the dialog is stifled because the browser
window isn't active when the hang is detected?)

At the most extreme, should this be recorded even earlier in
HungRendererDialogView::Show(), if there is no root window or if
logging::DialogsAreSuppressed()?

I'm not so sure that recording the number of times the dialog is shown (at least
like this) will correlate strongly with the number of detected page
hangs/crashes reported through other mechanisms...

https://codereview.chromium.org/819163002/diff/1/chrome/browser/ui/views/hung...
chrome/browser/ui/views/hung_renderer_view.cc:298:
content::RecordAction(UserMetricsAction("HungRendererDialogView.Closed"));
Should this also be recorded in HungRendererDialogView::TabDestroyed()?
Perhaps override DialogDelegate::OnClosed() to record this instead?

[Will Harris, 2015-02-28 21:14:09]

It seems the issue in the corresponding bug was fixed so no need to add these. 
Closing.